I have a 1997 Ford Taurus 3.0L. I have had long-crank slow-start problems for years. I found a tip that works excellent for this condition. I turn the key on but not to start. At this point, I hear a whirring noise under the hood. Once this whirring noise stops, then I turn the key from on to start, and my car starts immediately! It has worked wonders. My problem is: what is this whirring noise under the hood, and more importantly, what causes the noise to actually turn off? I understand the whirring noise itself isn't keeping the car from starting, but what controls it? It's like the car needs to check out a few things before turning off this whirring noise device. Another problem is this wait is getting longer and longer when it's getting cold in Minnesota. At other times, the whirring noise stops at differnent time spans - sometimes this whirring noise stops after two or three seconds, and sometimes it takes 20 seconds to stop. Please help. Thanks.

Are you sure the noise is under the hood? It could also be the fuel pump in the fuel tank. The pump is an electric motor that runs when the key is turned to the run position to prime the fuel system at startup. If you find you need to wait for the pump to shut off to successfully start the engine, your pump may be about to leave you stranded, or you may have a fuel system restriction such as a restricted fuel filter.

If you are confident that this noise is not your fuel pump, then it may be your Idle Air Control (IAC) motor on the throttle body controlling the amount of air that bypasses the throttle plate at idle and startup. The IAC will adjust the bypass air based on intake air temperature, coolant temperature, and load on the engine.

-Rod

Thanks for the ideas. The noise is definitely from under the hood. In the past week (colder outside temperatures have arrived here in Minnesota), the time it takes for this whirring noise to stop has increased from 5 seconds to around 30 seconds...sometimes. Anyway, this will give me time to turn the key on and quickly listen under the hood to where this whirring noise is originating. I will use your ideas. I will reply back to this post this tomorrow with more info and results.
I thought it could be the fuel pump going bad too so here is my idea about how I eliminated the fuel pump being the cause at this point: after driving around town for a half-hour I will turn the car off , then I will very quickly turn the ignition back to "on", but not "start", and yet that whirring noise is there and it still may take 20 - 30 seconds for it to stop. My theory here is if the car was running fine a few seconds ago then it must be getting adequate fuel pressure, so therefore, I will turn off the car and immediately try turning the key back to "on" thinking the whirring noise will stop real quick since the fuel pressure was just fine a second or two ago. But instead, the whirring noise may still run up to 20 or 30 seconds for whatever mysterious reason(s). Does this theory/test sound accurate? Or am I off target here?

A better check for if it's the fuel pump would be to unplug the fuel pump inertia switch in the trunk, then see if the the whirring is present. If the noise is still present, it is certainly not the fuel pump making the noise.

You could rule out the IAC by doing the same (unplugging the IAC motor). Be aware though that unplugging the IAC may cause a code to be set and a Check Engine Light.

Which 3.0L engine do you have, the 12V or the 24V DOHC?

-Rod

The whirring noise is for sure the two fans turning while the car is doing some sort of pre-start testing step(s). As soon as the "whatever" turns the fans off, I can start the car with absolutely no problems. Otherwise, if I were to turn the key from "off" to "on" then immediately to "start", then I have the common condition of long-crank hard-start occurring. So, what type of pre-start testing steps does a 1997 Taurus 12-valve do? Whatever it is will turn the fans on until some process is completed, then it turns the fans off. I know the fans being on are NOT the problem, it's just that is a great indicator when I can then turn the key from "on" to "start" with great results when starting the engine. I also have some other information. I noticed when I was directly over the fans (key "on" - engine "off"), that when the fans did get turned off by whatever process, then there was a click noise from the big module mounted alongside the battery box called the Constant Control Relay Module which has around 20-plus wires going to it. I am not sure if this last fact means anything. Last night the car took almost a minute for the fans to turn off before I could start the car. I notice as the weather is getting colder, the delay for the fans to turn off is also getting longer. I have had the car for five years, but this is starting to become a longer delay then I can ever remember. Please reply with any ideas you may have.
Thanks again, Rick

The only thing they do when you turn the key to on is display all the warning lights and prime the fuel pump.

My fuel pressure is right on according to the books specifications. I hooked a fuel pressure gauge onto the fuel rail for an accurate reading. Any other ideas? I have a feeling there are some pre-diagnostic computer programs or checks that the PCM (or other components) check or run through before other conditions are met that brings my car to this point where the fans also turn off. It also seems my entire problem gets worse with the outside temperature becoming colder too. Again, any more ideas? Thanks.

Hey everyone, I have more detailed facts, test results, and what-ifs for those of you that have your "thinking caps" on.

Here’s what I found out when I connected an inline spark tester on one of the plugs, connected a noid light on one of the injector harnesses, and connected a fuel gauge to the fuel rail on the car all at the same time during which time I had an assistant turn the key from "off" to "on" and immediately to "start" to turn the car over. (I know the car will not start due to the "fans being on", but I will at least see if I'm getting spark, injector pulse and fuel pressure during this brief time before the fans turn off.)

What I found out was absolutely no injector pulse, there was absolutely no spark at all, and the fuel pressure was perfect at 42psi while the car was cranking over just fine.

As soon as those "fans did turn off", then all of a sudden I had injector pulse, spark at the plugs, and the car started right off.

What would cause a 1997 V6-3.0L Taurus GL not to have injector pulse and not to have spark at the plugs while "the fans are momentarily on" when the key if first turned on from "off" to "on"?

After the above test was complete, I did some experimenting (or being desperate). Here’s some more interesting facts. Fact 1: I was troubleshooting my car during this time in a warm garage. Fact 2: The delay for the "fans to turn off" so I could actually start the car was about 5 to 10 seconds. Fact 3: The delay for the "fans to turn off" did not shorten or lengthen with the ECT (engine coolant temp) sensor disconnected, with the MAF (mass airflow) sensor disconnected, with the IAT (intake air temp) sensor disconnected, with the IAC (idle air control) sensor disconnected, and with the oil pressure sensor (feeds the dash board oil light) disconnected. Fact 4: this was very discouraging, but this morning when the garage was cold again, I went to start my car to go to work and the delay for the "fans to turn off" was back around 20 - 25 seconds. Fact 5: Once my car starts, ever, it has always ran fine. It has never stalled during driving conditions. My only dilemma is getting the car to start.

If anyone has any ideas, please let me know.

I have a OBDII code reader/scanner that can read generic and factory proprietary codes, individual sensors, and captured and live data.

I’m hoping all this detailed information above will mean something to someone that can help with this 1997 Taurus with its starting problems.

Thanks, Rick

Try turning the key to "run" and connecting with your scan tool. Will it connect while the fans are running, or only get communication once the fans stop?

I'll have to check on the 1997, but Ford used to use a Constant Control Relay Module (CCRM) which contained the relay for the PCM, fuel pump, cooling fans, and A/C compressor clutch.

If your Taurus uses a CCRM, I wonder if you maybe have a faulty ground to the CCRM. When the ignition is first turned to "run" the CCRM gets a ground through an incorrect path, turning on the cooling fans initially. After some time, the relay kicks out for whatever reason and then the PCM relay closes, allowing spark, fuel, etc. If your scan tool cannot connect to the PCM while the fans are running, that might indicate this is on the right path.

-Rod

Rod,

It's interesting you asked will I "only get communication once the fans stop?". That is EXACTLY what happens with my OBD-II reader. I get no data from the OBD-II connector until the fans stop. Is this a good clue about what may be happening?

Hmmmm... it seems you might have seen/heard of the above condition before. :-) I sure hope so.

What would be some ideas to try next, or tests to conduct at this point?

thanks, Rick

From my experiences (non-Ford) this would be indicative of a problem in the engine coolant temp sensor (CTS) circuit.

Fortunately for me, I have not experienced symptoms such as you describe. However, I do recall the older Taurii had a CCRM which contained the relays for the cooling fans, fuel pump, as well as the PCM power. Unfortunately, I don't have a service manual for the 1997 Taurus. My manual for the 1998 shows discrete relays for the cooling fans and PCM power. I'm not sure if 1997 was the same as '98 or if the 1997 has the CCRM.

Typcially the CCRM was mounted to the radiator core support. It has a bunch of wires (about 20 wires) connected to it. Don't mistake the airbag sensor for a CCRM (the airbag sensor will only have a couple of wires to it).

If you do have a CCRM, I would suggest tracing the ground wires and make sure it has good grounds. Unfortunately, since I don't have the service manual, I cannot tell you which wires should be ground. :(

In either case (CCRM or not) the PCM drives the relay coils for the cooling fans (high and low speeds). During normal operation, the PCM should have power in order for it to turn on the cooling fans. That along with your tool not being able to communicate while the fans run would suggest to me a ground issue or a PCM fault.

However, checking the coolant temperature sensor (not the sender) would be worthwhile. It is certainly less expensive to replace than the PCM and should be quick to either narrow down or rule out.

-Rod

Rod,

What do you mean to check the "coolant temperature sensor" but not the "sender"?

thanks, Rick

On many cars there are two devices in the coolant path, a coolant temperature sensor and a coolant temperature sender. Both devices look nearly identical. The sensor typically provides the temperature data to the Powertrain Control Module (PCM). The sender typically just drives the temp gauge/light on the instrument cluster.

Rod,
I have done some more tests.
1) check the grounds: the grounds seem very good, I also checked the ground at pin-15 in the CCRM harness and it showed a good ground although it had more resistance at key-on than key-off. (See table below)
2) disconnect the PCM to confirm the fans will come on: I disconnected the PCM and the fans did come on
3) check for power at the red wire at the injectors: the red wire does have 12volts at the injector harness while the engine is cranking but not started.

I also have some more extra information to help solve this situation.
The tach does not move at all during the time the key is turned from "on" to "start" during the no-start time period.
The ECT sensor had 64ohms while the outside temperature was 58degrees. The ECT also checks out fine with my OBD-II scanner (which can display real-time data readings) from engine start-up to proper engine temperature during test driving.

Why/how would a faulty ECT sensor tell a car not to provide spark to the plugs and not to provide electrical pulse to the injectors while the engine is cranking over?

I also tested some of the terminals at the CCRM harness when I had it disconnected from the CCRM with the key-on engine off, and during key-off.

Note: Terminal-13 seemed very suspicious with 0 volts at key-off
Terminal-15 has more resistance at key-on than key-off

Terminal-1 (cooling power low) had 0volts at key-on and key-off
Terminal-2 (cooling power low) had 0volts at key-on and key-off
Terminal-3 (battery power) had 12volts at key-on and key-off
Terminal-4 (battery power) had 12volts at key-on and key-off
Terminal-5 I did not test
Terminal-6 (cooling power high) had 0volts at key-on and key-off
Terminal-7 (cooling power high) had 0volts at key-on and key-off
Terminal-8 (battery power) had 12volts at key-on and key-off
Terminal-9 not used
Terminal-10 (battery power) had 12volts at key-on and key-off
Terminal-11 (battery power) had 12volts at key-on and key-off
Terminal-12 (battery power to PCM) had 7mVolts at key-on and 1mVolts at key-off
Terminal-13 (battery power) had 12volts at key-on and O volts at key-off
Terminal-14 I did not test since I didn’t know what type of signal to check for
Terminal-15 (ground) 60ohms at key-on and 2ohms at key-off
Terminal-16 no pin
Terminal-17 (high speed fan signal from PCM) - 3mVolts at key-on and 0volts at key-off
Terminal-18 did not test
Terminal-19 not used
Terminal-20 not used
Terminal-21 did not test
Terminal-22 did not test
Terminal-23 did not test
Terminal-24 did not test

Overall, I am asking myself what situation would tell a car not to provide spark to the plugs and not to provide electrical pulse to the injectors while the engine is cranking over and the fans are on, BUT once the fans turn off and the engine is allowed to start...this "whatever keeps the engine from starting while the fans are on" never interferes with the engine running at an idle or while driving once it has started (in other words the engine has never QUIT running once it has started)???

thanks, Rick

I'll have to sit down and think about all this good data.

As for it never interfereing once the car is running, have you heard the cooling fans run while driving due to engine temperature or due to having the A/C or defrost turned on?

The coolant temp sensor, even way out of range, should not prevent spark or injector pulse. However, a faulty crankshaft position sensor could. I don't know how the cooling fan would tie in to the that circuit though.

-Rod

Rod,

Thanks for tackling this problem.

My theory on this whole situation is this: some touchy relay is having problems within the CCRM or other location that provides power to the PCM (is there a PCM relay somewhere). Once this touchy relay is closed/open then the PCM finally gets its power to do its many functions including the following TWO ITEMS: 1) the PCM now having power can perform its proper instructions and send a signal to the CCRM where the fan relays are located and tell the fans to quit running and also 2) the PCM now having power can also signal to the rest of the car such as to allow electrical pulse at the fuel injectors and to allow spark at the spark plugs if and when the key is turned from "on" to "start".

If there is a PCM relay, where could it be? and could I jumper it during the "fans on but engine won't start" brief time period to see if I all of a sudden the fans turn off and I get spark at the engine?

Or should I scrap my entire relay/power theory, because it could be.............

I look very forward to your reply.

Have a nice weekend, and I will check back during the weekend.

I'll pull up the diagram for the 1996 CCRM. Back in 1993, the PCM relay was part of the CCRM [/URL]
[url]http://www.members.aol.com/Rod2414738/Car_Stuff/CCRM-1.jpg (http://www.members.aol.com/Rod2414738/Car_Stuff/CCRM-1.jpg%29)

Your theory sounds pretty reasonable, although I suspect more of a grounding issue since, in 1993, the relays were active low.

-Rod

I looked over the diagram for the 93 again and noticed a flaw -- the PCM relay is active high, the cooling fan relays are active low, but the power to the fan is supplied by the PCM relay, so in order for the fans to have power, the PCM relay would need to be closed as well. Or, there is some drastic wiring fault outside the CCRM.

I'll try to find a similar diagram for the 1996 which may be more similar to your 1997.

-Rod

Well, I don't have a 1996 or 1997 service manual like I thought I did. I have a 1995, and the 1995 Taurus was the previous generation, so that would be similar to my 1993 manual. :(

-Rod

I'm hardly a mechanic but I am an electronic tech and the crazy problem your having caught my attention, so maybe I can help.

Under the circumstances I would suspect the PCM itself but I do have another theory.

If the schematic that Rod posted is the same as your car and you measured the resistance from pin 15 to the negative battery terminal and got 60 ohms then there is your problem. Bad electrical connections can be thermally intermittent also, so you may be able to find the problem with a heat gun and a can of cold spray.

You also said that you have 0 volts on pin 1,2,6 and 7. If that is the case the fan couldn't run at all. Are you sure your testing it right. You should have pos. test lead on one of these and neg. on bat. neg. If your testing with your neg. lead on pin 15 and it does have a bad connection then you will get bad results.

Also a resistance measurment can be misleading. A voltage drop will tell you how much resistance is to high.

Try this: Measure the voltage between 15 and the neg. bat. terminal with key off and with key on. It should always read 0 volt. If you get any voltage (voltage drop will be directly proportional to resistance) then you have a bad connection. A few millivolts are OK, but if you get anything higher than say a half a volt then you should suspect the connections.

Note that you should be measuring this on the CCRM side of the connector in case the connector itself is the problem. Otherwise you could get a good test result when in fact the CCRM isn't getting a good ground. If you have an analog meter you should have neg. lead to bat neg. and pos. lead to 15. If you have a digital meter then it doesn't really matter.

Let me know something, because your strange problem has peaked my curiosity.

By the way, if you do get the right diagram/schematic I will be glad to help you test it.

I assume the relays are removable. If so try pulling the relays out 1 at a time and see what happens. That could tell you a lot. It would help a lot if you knew which relay you were pulling though. Aren't they labeled on the cover?

The CCRM is a sealed module. The relays are soldered to the board and the pins of the connector are not accessible without drilling out the rivets holding the CCRM together.

I think the next step should be to backprobe the terminals on the CCRM connector that control the relay coils as well as the signals from the switched side of the relays. This will help you identifiy if the PCM is telling the fans and fuel pump to run, or if the CCRM is definitely malfunctioning.

I found a copy of the 1997 service manual and it agrees with what you posted for pinouts. Pin 12 should have + battery voltage to it with the key on. If you are only getting 7mV with key on, there is a problem with that circuit. You may want to try temporarily tying pin 12 to battery voltage after turning the key on to see if the fans stop running and the car will start.

The voltage you are seeing on pin 13 is correct. However, as joeh100 mentioned, if you are seeing 0Vdc on pins 1, 2, 6, and 7, the fans should not be running. Try reversing the leads and see what the meter reads.

For pins 14 and 17, put the red meter lead on the positive terminal of the battery and the black meter lead on pin 14 and again on pin 17 and record the voltage readings. While you have the red meter lead on the positive terminal of the battery, make a measurement with the black lead on the pin 15. Now move the black lead to the negative terminal of the battery and see what voltage difference you have. Make these measurements with the key on and again with the key off.

According to the diagram in the service manual, there is a diode with the anode connected to pin 15 (ground) and the cathode connected to the fuel pump inertia shutoff. Pin 5 is supposed to have battery voltage with the key on, and is also tied to the PCM. Maybe this diode is faulty and causing a voltage offset on the CCRM ground which is causing only some of the relays to operate. This would help explain the 60 ohm reading versus 2 ohm readings you noted on pin 15. This diode is also located within the CCRM.

-Rod

I didn't know it was a sealed unit. That complicates things, lol. I think Rod hit on something with the diode though.

It is a counter emf diode for suppressing spikes coming from the fuel pump and it does provide another path to ground through the fuel pump. It doesn't have to be bad to provide the ground, however it is possible that the diode could have shorted and caused the wiring to open up somewhere between 15 and ground. You obviously don't have a good ground to the CCRM or you wouldn't have measured 60 ohms. This still seems like the problem to me (bad ground external to ccrm). Tell us what the voltage measurements are on 15. Resistance measurements aren't reliable when voltage is present and could even damage your meter.

I suspect the diode is still good because if it shorted you should have blown a fuse somewhere; but if you tell us what kind of meter you have, we'll tell you how to check the diode just to be on the safe side. You can check it externally if you disconnect the connector so no external wiring effects the reading. If it's a digital meter with the diode symbol --|>|-- it will be easy. If not you can still test it just a different way.

I didn't know it was a sealed unit. That complicates things, lol. I think Rod hit on something with the diode though.

It is a counter emf diode for suppressing spikes coming from the fuel pump and it does provide another path to ground through the fuel pump. It doesn't have to be bad to provide the ground, however it is possible that the diode could have shorted and caused the wiring to open up somewhere between 15 and ground. You obviously don't have a good ground to the CCRM or you wouldn't have measured 60 ohms. This still seems like the problem to me (bad ground external to ccrm). Tell us what the voltage measurements are on 15. Resistance measurements aren't reliable when voltage is present and could even damage your meter.

I suspect the diode is still good because if it shorted you should have blown a fuse somewhere; but if you tell us what kind of meter you have, we'll tell you how to check the diode just to be on the safe side. You can check it externally if you disconnect the connector so no external wiring effects the reading. If it's a digital meter with the diode symbol --|>|-- it will be easy. If not you can still test it just a different way.


Hello everyone.
I tried some ideas from Rod and joeh100.

I disconnected the CCRM harness from the CCRM and checked for voltage between pin-15 and the battery ground post with the key on and with the key off. I got 0.8mV with key-off, and I got 5.0mV with key-on.

I’m not sure if these next set of numbers are useful, but with the CCRM harness connected back to the CCRM I get these readings between pin-15 and the battery ground post: .8mV with key-off, 50mV with key-on and fans runnings, 13mV with key-on and fans finally turning off.

I re-ran my resistence test between pin-15 and the battery ground post. I still get 2ohms with key-off, however, it now reads 13ohms with key-on. A few days ago, I had 2ohms with key-off and 60 ohms with key-on. I re-ran this test many times when testing both nights.

extra notes: My earlier post with all 24 pins listed and test results were when the CCRM harness was disconnected from the CCRM. So some of my tests may be invalid. An example would be pin-12 which is "Battery power to the PCM"...in this case there would be 0 volts with the "key on" or with the "key off" since the CCRM harness that I'm testing is disconnected at the moment, so it is absent of power (see my follow-up Pin-12 test further below). I just wanted to mention this situation since I do NOT want to waste anyone's time here with inaccurate information on my part. If I need to retest or do a test differently, please let me know.

I am using a digital tester - Meterman 34XR.

Rod: I tried the idea of related to your response of "I found a copy of the 1997 service manual and it agrees with what you posted for pinouts. Pin-12 should have + battery voltage to it with the key on". This time I tested with the CCRM harness still connected to the CCRM. With the "key off" I get 0.7mV, and with the "key on and fans running" I get 12volts, and with the "key on and fans finally turned off" I get 12volts. Does pin-12 seem okay?

joeh100: are you still need of a 1997 Taurus GL wiring schematic? I will try to find one online for you if you do. I have a Haynes manual with the wiring diagrams in the back of the book for my use. Thanks for offering to instruct me on how to troubleshoot/test various circuits.

I'm open to the next set of ideas/steps/tests. thanks to all, Rick

Keep in mind that I'm using the diagram that Rod posted for my assumptions. If its too different from yours then I may be barking up the wrong tree. If I had access to the correct diagram I could tell you how to static test everything in the ccrm except the solid state relay and voltage inverter. You'll have to test these 2 under operating conditons, not a big deal though.

I’m not sure if these next set of numbers are useful, but with the CCRM harness connected back to the CCRM I get these readings between pin-15 and the battery ground post: .8mV with key-off, 50mV with key-on and fans runnings, 13mV with key-on and fans finally turning off.

That would suggest a good ground. Also try this same test with one lead on pin 15 and the other to bat. pos. It should be the same as the bat. voltage. 12-14 V. Also when you tested the resistance was this with the ccrm connected or not?

If the diagram I am using is similar then this is how to test the diode that Rod mentioned. First disconnect the ccrm. Set your meter to the diode test mode -|>|-. First connect the pos. lead to pin 5 and neg lead to pin 15. Meter should read OL. Next swith the lead polarity. Pos. to pin 15 and neg. to pin 5. Meter should read between .5 and .7 V (decimal place actually depends on the meter. It could show 500 to 700 if in mV) Just look for the numbers 5 to 7.

The solid state voltage inverter that is in the diagram that Rod provided is also a suspect component that needs testing.

joeh100,

My resistance test was performed with the CCRM harness disconnected from the CCRM.

If the diagram from Rod is from a 1996, then the diagram should work for a 1997 also. The only reason I say "yes" to this is that the CCRM relay part number (Airtex # 1R1573) at rockauto.com is the same CCRM relay part number for a 1996 or a 1997 Taurus GL. What I have in my Haynes manual does not have as much detail as the diagram supplied by Rod.

If anyone else has a link to a 1997 CCRM schematic, please let me know.

joeh1000, in the meantime, I will follow-through this evening with your latest reply.

Rod,

Was the following link that you supplied for a 1997 Taurus GL?:
http://www.members.aol.com/Rod241473...uff/CCRM-1.jpg

thanks, Rick

Nope, that link is for a 1993. I have a somewhat similar diagram (well, 2-part diagram) for the 1997 if you are looking for it. Send me a private message with your request and an e-mail address for you that can accept PDF attachments and I'll send it your way.

-Rod

Rod,

I will private message you for the correct 1997 schematic.

joeh100, can you also private message Rod with an acceptable email address to receive this two-part Taurus 1997 GL schematic for any future test ideas you may have???

(note - see my very next reply in this post with the latest test ideas completed)

T H A N K S again to all for helping, Rick

Here are some more test results.
1) I found no PCM relay module in the fuse box area above the radiator. The only PCM relay I can found is the one in the CCRM. I did drill out the rivets and open up the CCRM. I saw nothing unusual as far as dirt, burnt circuits, etc.

I also took out all the relays one at a time that were found in the fuse box above the radiator. Each time the fans would still turn on as the key was turned from "off" to "on".

2) I disconnected the CCRM harness from the CCRM and the fans did NOT turn on as the key was turned from "off" to "on". Not sure if this test means anything.

3) With the CCRM harness connected to the CCRM, I tested the voltage at the suspicious pin-13 (power) as seen in previous replies. The test results were:
key-off: 0 volts
key on fans running: 12 volts
key on fans finally off: 12 volts.

4) With the CCRM harness connected to the CCRM, I measured the resistance at pin-15 which seems to be the only ground for the CCRM according to the my Haynes manual. The test results were:
key-off: 0 1.9 ohms
key on fans running: 110 ~ 140 ohms
key on fans finally off: 22 ohms.
DOES THIS TEST INDICATE ANYTHING...IT SEEMS 110 OHMS IS HIGH ?!?!?!

I then grounded pin-15 directly to the battery ground post, and nothing
improved...the fans still kicked on when the key was turned from "off" to "on".

I then grounded pin-15 through the DMM and the direct ground results were identical to above:
key-off: 0 1.9 ohms
key on fans running: 110 ~ 140 ohms
key on fans finally off: 22 ohms.
DOES THIS TEST INDICATE ANYTHING...IT SEEMS 110 OHMS IS HIGH ?!?!?! AGAIN!

5) With the CCRM harness connected to the CCRM, I tested the voltage to the battery positive post while using pin-15 as ground (the CCRM ground signal):
key-off: 12 volts
key on fans running: 12 volts
key on fans finally off: 12 volts.

6) With the CCRM harness DIS-connected from the CCRM, I followed the instructions on how to test diodes. I first connected the positive lead to pin-5 on the CCRM module box (not the CCRM wire harness) and I connected the negative lead to pin-15 on the CCRM module box. My test meter read O L. Next, I switched the positive lead to pin-15 on the CCRM module box and switched the negative lead to pin-5 on the CCRM module box. I expected the meter to read .5 ~ .7 volts. However, the meter stayed at 0. Provided that I tested using the correct steps, does this test result point out anything obviously wrong? Did we find the bad link of the puzzle here?

Is there a different diode I can test on the CCRM module box just to make sure I am testing correctly, and the meter will properly read a diode, any diode, correctly? I had the meter set to the ->|- setting.

I look forward to the above multiple test results being analyzed by others. I am no mechanic.

On another note, I ordered a Ford 1997 Taurus manual on cd-rom from eBay. Hopefully, this will help answer some questions anyone may have. The website claimed this cd-rom contained schematics, pin-outs, troubleshooting ideas, etc. I am not a mechanic by trade, so I am trying to learn as I go here. I do not enjoy car troubles, but I do NOT mind learning during the course of having car troubles such as the above conditions.

Anyway, let me know what others may be thinking. It would be appreciated again. Rick

More good testing (for the most part). My input:

1) You got the expected results for a working CCRM.
2) Again, expected for a working CCRM.
3) Pin 13 is "Hot in Start or Run." You got the expected results for a working CCRM.
4) You got expected result. However, your readings with the key on is not a meaningful check as joeh100 mentioned. Making these readings with the key on COULD damage your meter. Your changing resistance readings are likely caused by voltage through the relay coils.
5) Expected results. Pin 15 is ground and since you always read 12V, your ground reference must not be shifting.
6) "OL" with the red lead on pin 5 and the black lead on pin 15 is correct and expected. However, "0" with the red lead on pin 15 and the black lead on pin 5 is not what I would expect. Did you really see "0" or did you mean to type "OL?" If you really saw zero, that would imply there was absolutely no drop across the diode when forward biased. That would indicate a goofy diode. Try the same check, but use the resistance setting of your meter. What resistance reading do you get with the red meter lead on pin 15 and the black meter lead on pin 5 and the CCRM disconnected?

There is another diode in the CCRM that you could test. It is positioned between pin 23 (cathode) and pin 15 (anode). With the CCRM disconnected, you can test this diode in exactly the same way you tested the other diode, but substitute pin 23 for pin 5.

Keep in mind here that the diagram we are using is more of a block diagram than a schematic. There is a chance other components exist in the circuit that are not showing in the diagram and could be skewing our expectations. Do you happen to have any acquaintances that have a 1997 Taurus with the same options as yours? Maybe you could swap CCRMs with them, or at least perform non-destructive out-of-circuit checks on theirs for reference?

I'd also be very curious to see what kind of voltages you get on pin 14 and pin 17 with the key on, fans running and key on, fans off. For these measurements, have the red meter lead on the positive terminal of the battery.

If the above measurements yield "0V" on pin 14, then move the black meter lead to battery negative and the red meter lead to pin 14.

Pin 17 is the high speed relay coil signal (ground potential) from the PCM. Pin 14 is the low speed cooling fan signal from the PCM. This signal on pin 14 does not go to the relay coil directly though, rather it goes to a solid state relay driver. It's unclear if the signal on pin 14 should be at ground potential, +12V, +5V, or some other logic level.

-Rod

Rod's right, the relay driver is probably the problem. Is it made with discrete components? Are there any transistors on the board? They will be black and shaped like the letter D. Do you have a digital camera?

How well are you at splicing wires back together. The easiest way to test is just cut the wire at pin 14 (the low speed wire, cut long enough to repair easily) and see if the fan still comes on. If this is the problem the fan may or may not run but your car should start right up with no problems. If so we'll try and explain how to fix it. Leave the wire cut for now.

Also measure the voltage on that wire on the side coming from the PCM during all conditions and post results.

There are numerous solid-state devices in the CCRM that I took apart years ago. In addition to TO-18 transistors, there were also a few TO-220 transistors, as well as some logic circuits with house part numbers and the expected passive components.

At this point, I'd suggest looking into a replacement CCRM from a salvage yard before cutting any wires. I don't expect that they'd be all that expensive. Just make sure you have the part number and any large, bold letters from the case of your CCRM when trying to find a replacement.

If you can get a chunk of the mating plug for the CCRM and really want to figure out what's happening, you could build a breakout cable using the mating connector/cable and the board-mount connector from a third CCRM.

If you decide a replacement CCRM is too expensive to experiment with right now, you can probably remove the terminal from location 14 by disassembling the connector. Those connectors used to have a red terminal retainer on the connector face that can be popped out and the terminals removed. Just be sure to hold on to the wires so they don't come out until you are ready to take them out.

-Rod

Rod, joeh100:

Thanks for the feedback...it feels good to make progress.

Rod, I can rerun the diode test from above (item #6) again and post the results this evening. Can you confirm with the 1996/97 schematic I am using the correct pins for the diode tests above?

In reference to your previous question: I feel very comfortable cutting wires, splicing, labeling, soldering, etc. If anyone has any "absolute yes or no, or go or no go tests" that involve cutting wires, re-wiring, etc. then let me know. That will be no problem. If fact, it would be nice to try and corner what area the problem COULD be in, or corner what area the problem may NOT be in. I'm not sure if I am making sense here but in other words it would be nice to come up with some tests that positively indicate a certain direction as far as good or bad (no in-between results)...and if this involves some side-wiring, cutting, modifying, etc., then let me know.

I was also thinking this morning, that if we start running out of clean tests to conduct, I may end up taking a chance and start buying parts to replace. This is why I welcome the next round of tests or ideas (before buying anything) that may involve some side-wiring, cutting, modifying, over-riding, etc.

My strategy is to positively eliminate any bad connections or factory wiring, and then focus on either replacing the CCRM and/or the PCM.

thanks, Rick

Rod,
I will conduct all your stated tests this evening. I do not have any friends with another CCRM to swap out.

In my test above (test #1), the relays I took out one at a time were for windshield wipers, blower motor, horn, auto LP HD/LP, etc. I just wanted to make sure nothing unusual would happen by taking out any relays I found in this area of the car.

joeh100,
When you stated "the relay driver is probably the problem", is this part found inside the CCRM? I do have a digital camera. I took pictures last night of the relay box above the radiator to confirm I have no PCM relay in this area...meaning my only PCM relay I know of is inside the CCRM.

thanks, Rick

Damn Rod, for a mechanic I'm impressed with your electrical skills/knowledge.
Just guessing, you are a mechanic aren't you?

Anyway...
I wouldn't have suggested cutting a wire if I wasn't pretty sure where the problem was. Right when the PCM powers up it has to send a logic "high" to keep the fan from running.
My theory: The relay driver is bad in the CCRM and loading the PCM. The only way to tell is to isolate them by removing that connection. If you can remove the terminal without cutting the wire that will be better. If this is the problem you will know immediately because the car should start right up without problems. That's a definate go or no go test. It is possible the driving device in the PCM is bad also, but unlikely. Once they are isolated it will be easy to test though.

If the transistors are TO-18 and TO-220 as Rod said then they will not look like the letter D. Those are TO-92 devices. I'm not sure how much a replacement CCRM would be, but if we could isolate a bad transistor you could buy a replacement from Radio Shack and get someone to replace it fairly cheap. However if an IC is bad and it is an OEM part (house numbers) then your probably out of luck getting any data on these. I worked on a car radio once and some of the IC's had "Ford" and their part number printed on them. Needless to say, the radio did not get repaired.

joeh100,

What is meant by a logic "high"?

My automotive electronics knowledge base is probably a "beginner" level.

Rick

I said logic high because we don't know about the driving circuitry in the pcm yet. A logic high could be any voltage above ground or it could be simply an open circuit, it depends on the pcm. If the pcm is being loaded then you can't test this without breaking the connection between the pcm and the ccrm.

Taurus1997, your labeling of the pin functions for the CCRM agree with the labeling of the Ford factory service manual.

Damn Rod, for a mechanic I'm impressed with your electrical skills/knowledge.
Just guessing, you are a mechanic aren't you?
Nope, I'm a Sr. Systems Engineer with a degree in Electrical Engineering. Working with cars is just a hobby of mine.

If the transistors are TO-18 and TO-220 as Rod said then they will not look like the letter D. Those are TO-92 devices.

Oops, that's what I get for going off memory. Some of the small signal Q's are TO-92 (plastic case, not metal can) while the larger driver Q's are TO-220.

-Rod

LOL, well that explains a lot. You seem to have access to a lot of data on different year models and stuff and you know a lot about cars. I just assumed you where a mechanic.

Here is more information about the two diode tests.

A) I re-ran the diode test with the CCRM harness disconnected from the CCRM module box. I first connected the positive lead to pin-5 (inertia fuel shutoff to motor) on the CCRM module box and I connected the negative lead to pin-15 (ground) on the CCRM module box. My test meter read O L. Next, I switched the positive lead to pin-15 on the CCRM module box and switched the negative lead to pin-5 on the CCRM module box. I expected the meter to read .5 ~ .7 volts. However, the meter stayed at 0 L.

note: the resistance test across pin-5 and pin-15 showed 0 ohms...the meter reading never moved at all.

B) I also ran a diode test using pin-15 and pin-23. I first connected the positive lead to pin-23 (power to A/C compressor clutch coil) on the CCRM module box and I connected the negative lead to pin-15 (ground) on the CCRM module box. My test meter read O L. Next, I switched the positive lead to pin-15 on the CCRM module box and switched the negative lead to pin-23 on the CCRM module box. I expected the meter to read .5 ~ .7 volts and I got 0.599 !

Do the above two diode tests with different results point anything out? Remember, I am the "gopher" here while you are the "brains" behind this operation. :-)



I also ran some additional voltage tests too with the CCRM harness connected back to the CCRM module box.

D) With the red meter lead on the positive battery post, and the black meter lead at pin-14 (low speed fan signal from PCM) I get the following:
key-off: 12 volts
key on fans running: 300 mVolts
key on fans finally off: 12 volts.

E) With the red meter lead on the positive battery post, and the black meter lead at pin-17 (high speed fan signal from PCM) I get the following:
key-off: 12 volts
key on fans running: 130 mVolts
key on fans finally off: 50 mVolts.

Does test E) indicate anything unusual compared to test D)? The voltage is different for test D) and E) at "key on fans finally off".

F) With the black meter lead on the negative battery post, and the red meter lead at pin-8 (power) I get the following:
key-off: 12 volts
key on fans running: 12 volts
key on fans finally off: 12 volts.

G) With the black meter lead on the negative battery post, and the red meter lead at pin-10 (power) I get the following:
key-off: 12 volts
key on fans running: 12 volts
key on fans finally off: 12 volts.

That’s all the testing I did last night. I did not get a chance to intercept pin-14 (low speed fan signal from PCM) under a starting condition. I will do that this evening.

So, have we made progress here with all the above test data?

I am still new to car electronics for this next question: if we figure out how to keep the fans from turning on when turning the key from "off" to "on", will this situation then provide the missing electrical spark to the plugs and provide the missing electrical pulse to the injectors so the car will start? (I get no spark to the plugs or electrical pulse to the injectors as long as the fans are running during startup...as soon as those fans turn off...my car starts immediately and easily).

thanks again to everyone for their time and input,
Rick

Keep in mind that I don't have the correct diagram, but your first test shows an open diode. You said that you measured the resistance also and it stayed at 0. This is an impossible contradiction. Are you sure the resistance didn't read OL. There is a big difference between 0 and OL. 0 is zero resistance and OL is over load or out of range. If your meter is autoranging then OL means infinite (for all practical purposes).

If this diode is open it's possible that noise is feeding back into the PCM and causing problems.

Does the fan run only when there is voltage going to the fuel pump?
Test for any AC voltage on pin 14, and on the power wire to the PCM.

There's a wire coming off the fuel pump and back into the the PCM I assume is for the PCM to test the fuel pump. It's possible this wire is introducing noise into the PCM. Just a guess though.

The other tests suggest that the PCM is telling the fan to run for whatever reason and not what I expected. Yes test D and E should be at different voltages when the fan is off. I don't have the right diagram but I believe test F and G are good.

If you could isolate signals between the PCM and the CCRM you could eliminate one or the other as the problem.

Rod, how are the electric ignition and the injectors driven? Right from the PCM? I assume that during inital power up the PCM wouldn't bother driving the ignition or the injectors until the fuel pressure is ok.

Are there other wires in the same wiring harness that go to the fan?

joeh100,

I will re-run the resistance test tonight.

I have 42psi of fuel pressure immediately as the key is turned from "off" to "on".

I will also test for AC voltage on pin-14 at the CCRM.

I will also test for AC voltage on the power wire going to the PCM.

Rod has the correct 96-97 CCRM wiring diagram. You would have to private email him with an acceptable email address for him to send you back the CCRM wiring diagram as attachments.

Another test I will run tonight is to disconnect pin-14 and see what happens.

thanks for your ideas,
Rick

Also make a note of what the fuel pump is doing while the fans are running. Just measure voltage on that pin.

joeh100, Rod:
In reference to the diode test A) from yesterday, and how I tested for resistance between pin-5 and pin-15, and how I got 0 as a stated result, and joeh100 stating that is an impossible contradiction....well joeh100 was right. I re-did the resistance test between pin-5 (inertia fuel shutoff to motor) and pin-15 (ground) and the result I got was 0.L

I was wrong to have stated the test result was 0.

I am kind of anxious to hear back if the above test is our smoking gun as to what the problem is. Is it????


I also ran a few more tests.
AA) With the CCRM harness connected to the CCRM module box I tested for AC voltage on pin-14 (low speed fan signal):
key-off: 160 mVolts
key on fans running: 160 mVolts
key on fans finally off: 160 mVolts

BB) With the CCRM harness connected to the CCRM module box I tested for AC voltage on pin-24 (power to PCM):
key-off: 10 mVolts
key on fans running: 10 mVolts
key on fans finally off: 10 mVolts

note: I believe there could be a problem with test BB) above. My Haynes manual for 1996-2001 Taurus says pin-24 is "power to PCM", but the .pdf attachments that Rod sent to me says pin-24 is "high-speed Electro-Drive fan".
Rod, which one is correct?


CC) With the CCRM harness connected to the CCRM module box I tested for a resistance readling on pin-18 (fuel pump relay ground) with my black test meter lead on the battery negative post:
key-off: very, very little ohms
key on fans running: very, very little ohms
key on fans finally off: very, very little ohms

I thought with pin-18 being a ground, that I would put my test meter in resistance mode and see a resistance reading output???

Anyway, things got interesting when I then put my test meter in DC voltage mode with the black test meter lead on the battery negative post and got the following results:
- key on and fans running: 180 mVolts
- then the CCRM did some clicking noise
- then the fans finally turned off
- then I got 0 volts for a split second
- then the CCRM did another clicking noise
- then I got a steady 12volts (at which time the key was "on" and the fans finally off).

Hhmmm???? Does this mean anything???

The last test of the evening was where I cut pin-14 (low speed fan signal from PCM), turned the key from "off" to "on" and immediately to "start"... but the car did NOT start until a lot of cranking of the engine.

What I DID discover in chronological order on subsequent attempts with pin-14 cut was this:
- the key would be turned from "off" to "on"
- the fans would turn on like usual
- the CCRM module box would make a clicking noise
- the fans would KEEP RUNNING anyway instead of turning off ! ! !
- I would try starting the car anyway and the car would start just fine with the fans still running.

Okay. Now I am really confused about what all this test data means from this evening. Please, please help me decipher what it means.

Today the temperature was very cold (20 degrees) compared to the previous days, and my car at one particular start-up took almost two minutes for the fans to turn off so I could start my car. This only happened once. The average wait today was around 30 seconds for those fans to turn off.

I will be anxiously waiting for any feedback, replies, test ideas, recommendations, humor, instructions on how to sell my car,etc. :-0

thanks, Rick

Sorry, I'm getting a late start tonight. I'll have to find another time to digest what has transpired since my last post.

As for the function of pin-24, normally I'd trust the factory service manual over a Haynes. However, in this case, the block diagram shows pin 24 as being in parallel with pin 12 and coming from the EEC Relay, so the Haynes manual is likely correct (as is the block diagram from Ford).

Pin 18 is the ground signal for the fuel pump relay coil, but is not a constant ground. Ie: this line is active low, when a ground is provided by the PCM, the fuel pump relay is closed.

I'll have to go back and re-read, but why were you testing with your meter set to AC? Were you looking for noise?

-Rod

Instead of pin 18 I meant to test the output voltage to the fuel pump (I think pin 5). I am interested to know if the fuel pump is also running while the fans are running during initial start up.

Your resistance test confirms that if a diode is suppose to be between those connections, then it is open.

The AC noise test seems to show no signifigant noise.

The strange clicking could have been the result of the open input to pin 14. That and the fact that the fans continued to run does not necessarily mean anything is wrong yet. Was the wire cut at that time. Also, you didn't mention where your pos. test lead was. Just that the neg. was to bat. neg.

Rod, do you think he could tie the CCRM input wire at pin 14 straight to bat pos to test the proper function of the CCRM or do you think the input should be "pulled high" through a resistor. This could positively indicate the PCM is the culprit for whatever reason. Not necessarily bad but something other than the CCRM is the problem.

I don't see how the diode could be causing the problem but you never know.
Also do you think that the counter emf diode to the fuel pump is not in his CCRM but rather at the fuel pump.

I'm confused have you absolutely guaranteed good power to the PCM. There are a lot of power wires coming off of the CCRM. It would be VPWR on the diagram that ROD posted.

In the meantime since you've already drilled the rivets to the CCRM try tracing down that diode back to the connector and test the diode both ways in the diode test mode with your meter.

If for some reason the high and low speed fan relays where engaged this could cause a problem. Try disconnecting the fan during startup.

Rod is the fan suppose to always run when the AC compressor is on even if it is cold outside?

The clutch to your AC compressor isn't always running for some reason is it?
Do you have electronic climate control in that car?

I won't suggest anything else until Rod chimes in. Rod Since the failure is so directly related to temperature do you think another problem somewhere could have exposed a problem in the PCM source code.

And finally you asked for instructions on how to sell your car. Make sure it is nice and warm when you sell it. :grinyes:

joeh100,

You had asked "...Was the wire cut at that time. Also, you didn't mention where your pos. test lead was. Just that the neg. was to bat. neg..."
and your answer is "the wire was NOT cut at the time, and the red positive test lead was still on pin-18 as per test CC above".

You has asked about "...absolutely guaranteed good power to the PCM..."
and my answer is from post #15 on the first page of this thread where I initially tested a lot of wires:

(note: Terminal-12...could this be a clue???)

Terminal-3 (battery power) had 12volts at key-on and key-off
Terminal-4 (battery power) had 12volts at key-on and key-off
Terminal-5 I did not test
Terminal-6 (cooling power high) had 0volts at key-on and key-off
Terminal-7 (cooling power high) had 0volts at key-on and key-off
Terminal-8 (battery power) had 12volts at key-on and key-off
Terminal-9 not used
Terminal-10 (battery power) had 12volts at key-on and key-off
Terminal-11 (battery power) had 12volts at key-on and key-off
Terminal-12 (battery power to PCM) had 7mVolts at key-on and 1mVolts at key-off
Terminal-13 (battery power) had 12volts at key-on and 0 volts at key-off

Is Terminal-12 suspicious???

Also, the A/C clutch is not running and I do not have automatic climate control neither.

thanks, Rick

I will retest Battery Power wires 3, 4, 8, 10, 11, and 13 tonight with more detail of
key-off:
key on fans on:
key on fans finally off:

I will also retest Power to PCM wires 12 and 24 with more detail of
key-off:
key on fans on:
key on fans finally off:

I will also test the voltage at pin-5 which is Inertia Fuel Shut-off.

thanks, Rick

Oh yes, I will also try disconnecting the fans too for a start-up test.

Rick

Sorry about all of these individual posts from myself in a matter of minutes, but what do you guys think of this test:

I notice the wait time for the fans to turn off is getting longer and longer as the temperature is getting colder. I will still conduct the previous tests that I mentioned in my previous posts. However, when I am done testing for the night, I will leave my car outside overnight in the cold temperatures but bring into the house the CCRM module box itself to keep it nice and warm. Tomorrow morning, I will connect the CCRM module box back into the car and see what happens with the delay for the fans to turn off.

How about that "undocumented Ford test" ???????? :-) :-0

Rick

Sorry about all of these individual posts from myself in a matter of minutes, but what do you guys think of this test:

I notice the wait time for the fans to turn off is getting longer and longer as the temperature is getting colder. I will still conduct the previous tests that I mentioned in my previous posts. However, when I am done testing for the night, I will leave my car outside overnight in the cold temperatures but bring into the house the CCRM module box itself to keep it nice and warm. Tomorrow morning, I will connect the CCRM module box back into the car and see what happens with the delay for the fans to turn off.

How about that "undocumented Ford test" ???????? :-) :-0

Rick

I think that sounds like a very good test!

I'm going to print out the last few day's worth of postings to review when I want to exercise my brain. Work's been keeping me here 16 hours a day this week. :(

-Rod

Rod, joeh100:

I just remembered that when I did all my testing (post #15 on page 1 of this topic) I had the CCRM wire harness disconnected from the CCRM module box. I will re-test all the power wires tonight as stated above AND with the CCRM wire harness connected to the CCRM.

Rick

OK, I'm just shooting from the hip now but here are some other ideas.

Did you ever actually test the engine coolant temperature sensor?

If the car is running extremely hot the PCM will not supply ignition to certain cylinders. In essence using them as heat pumps to protect the engine. This could make the car damn hard to start. It should set an error code though, so I'm not sure.

Not a bad idea to test it though.

Also the voltage on pin 18 seems to suggest that the fuel pump is running while the fans are running. I'm not a mechanic but I don't think it's good for the fuel pump to run for 2 min's straight. You said before that you have 42 psi right when you hit the switch, so why would the fuel pump need to run for so long. Again I would expect the PCM to set an error code if the fuel pump had to run for that long.

Isn't there a fuel pressure sensor or switch somewhere that can be tested?

When's the last time the battery got disconnected. Disconnecting the battery for a while would cause a full system reset of the PCM data and may fix any flaws if present in the source code.

If all else fails, Rod and I will come visit you personally. With our combined knowledge and expertise, we should be able to get you going again in no time. It shouldn't take longer than an hour to burn your car to an empty shell and make it look like an accident. How good is your insurance?

Still tired from work, but a couple of quick clarifications.

I don't believe the Taurus engines will operate as a heat pump. The Lincoln LS engines will, but I don't believe the cylinder head temperature sensors are employed on any of the Taurus engines. However, I would still like for Rick to get a reading of the sensor (and, again, not the sender). Until I have a chance to look at the diagrams though, I'm not sure how to tell you to distinguish one from the other.

Also, the fuel pump on these cars is an electric motor. During normal operation when the engine is running, the fuel pump is running continuously. There is a fuel pressure regulator on the fuel rail that should prevent the pressure from getting too high.

Hmm, Minnesota isn't too far from Iowa....My sister in-law lives in St. Paul on Portland Ave. and says we don't visit her enough.... :)

-Rod

Rod, joeh100:

We really need to fix my problem fast....I don't want no midnight yard sale fires!!!!! LOL...............really...........LOL.

Thanks for the humor.

About the ECT sensor (and not the sender): I checked it with a resistance test and my meter, and it was okay. I also tested this same sensor with my OBD-II scanner that can read real-time data for any sensor, and my scanner showed very nice temperatures throughout my test drive for the ECT. I also left the ECT sensor disconnected during one of my earlier tests, and the fan delay did NOT change at all.

Referring back to my post #8 on page 1 of this topic:

I connected an inline spark tester on one of the plugs, connected a noid light on one of the injector harnesses, and connected a fuel gauge to the fuel rail on the car all at the same time during which time I had an assistant turn the key from "off" to "on" and immediately to "start" to turn the car over. (I know the car will not start due to the "fans being on", but I will at least see if I'm getting spark, injector pulse and fuel pressure during this brief time before the fans turn off.)

What I found out was absolutely no injector pulse, there was absolutely no spark at all, and the fuel pressure was perfect at 42psi while the car was cranking over just fine.

As soon as those "fans did turn off", then all of a sudden I had injector pulse, spark at the plugs, and the car started right off.

What would cause a 1997 V6-3.0L Taurus GL not to have injector pulse and not to have spark at the plugs while "the fans are momentarily on" when the key is first turned on from "off" to "on"?



joeh100, I would NOT say my car is hard to start while I'm cranking the engine, I would say my car won't start at all while I'm cranking the engine with those fans on...meaning I don't think the ECT is interfering. Just a guess.

I also get no emission codes at all.

I have not disconnected the battery in a long time. I will do that this weekend...can't hurt to try.

About the fuel pump idea: my test results this evening may lend some attention in this area.

I will post these test results from this evening here in a few minutes after I get them typed in.

thanks, Rick

I did have one question from yesterday before I get into this evenings test results.

When I re-ran the diode test for resistance between pin-5 (inertia fuel shutoff) and pin-15 (ground) and got 0.L, did this result/test conclude anything?????? Also remember, when I checked pin-5 and pin-15 with my meter in diode mode and switched the leads I got 0.L both directions. What was the conclusion from the data above????? As expected, inconclusive, still don’t know?????

Here are this evenings test results.

I disconnected the wire harness at both cooling fans, and the car still would not start when I turned the key from "off" to "on" and quickly to "start". The car did start as soon as I heard that click several seconds later coming from the CCRM module box.

Moving on, I tested the CCRM wires with the CCRM wire harness connected to the CCRM module box. All tests had the black test meter lead on the negative battery post except for pin-18.

I find the following test results for pin-5 and pin-24 interesting. Could this mean anything?

Pin-1: low electric cooling fan power
key off: 1 mVolt
key on fans on: 12 volts
key on fans finally off: 3 volts then it went down to 8.0 mV within a couple of seconds

Pin-2: low electric cooling fan power
key off: 1 mVolt
key on fans on: 12 volts
key on fans finally off: 3 volts then it went down to 8.0 mV within a couple of seconds

Pin-3: battery power
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-4: battery power
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-5: inertia fuel shutoff
key off: 1 mVolts
key on fans on: 12 volts
key on fans finally off: 10 mVolts

Pin-6: high cooling fan power
key off: 1 mVolts
key on fans on: 9 volts
key on fans finally off: 3 volts then it went down to 8.0 mV within a couple of seconds

Pin-7: high cooling fan power
key off: 8 mVolts
key on fans on: 9 volts
key on fans finally off: 3 volts then it went down to 8.0 mV within a couple of seconds

Pin-8: battery power
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-9: no wire

Pin-10: battery power
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-11: battery power
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-12: BATTERY POWER TO PCM
key off: 1.4 mVolts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-13: battery power
key off: 0.5 mVolts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-14: low speed fan signal from PCM
key off: 1 mVolt
key on fans on: 12 volts
key on fans finally off: 40 mVolts

Pin-15: ground
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-16: no wire

Pin-17: high speed fan signal from PCM
key off: 1 mVolt
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-18: fuel pump relay ground <---- with black test meter lead on the negative battery post
key off: 1 mVolt
key on fans on: 200 mVolts
key on fans finally off: 1.0 mVolts
...same pin test again but with wires switched
Pin-18: fuel pump relay ground <---- with red test meter lead on the positive battery post
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 50.0 mVolts

Pin-19: no wire

Pin-20: no wire

Pin-21: A/C clutch signal to PCM (A/C was off in the car)
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-22: wide open throttle signal to PCM
key off: 1 mVolt
key on fans on: 12 volts
key on fans finally off: 100 mVolt

Pin-23: power to A/C compressor clutch (A/C was off in the car)
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 12 volts

Pin-24: POWER TO PCM
key off: 1 mVolt
key on fans on: 60mVolt
key on fans finally off: 1 mVolts

It seems like pin-5 (inertia fuel pump) is 12 volts until the fans turn off.

I am also going to test Pin-24 again tomorrow just to make sure those test result numbers repeat themselves.

My last test for the evening is with the CCRM module box in the warm house, and the car is outside of the garage in the cold weather tonight. Tomorrow morning, I will reconnect the CCRM module box into the car. I will then turn the key from "off" to "on" and see how long the delay is for those cooling fans to turn off. It will be VERY interesting to see what happens. To tell you the truth, I’m not sure what result would be favorable from this test.

Hhmmmm. I will leave that up to you guys to decipher.

Have a good evening,
Rick

I am not a mechanic, I was just throwing some stuff out there for ideas.

I was wrong about the cooling fan test. With the new diagram Rod sent me, it doesn't matter if both the high and low speed relays engage at once because of the way they are controlled. On the other diagram it could have mattered. Sorry about that.

First, yes the diode is open, can you trace it down and test it in circuit to confirm. It does need to be replaced. I'm not sure how this could cause the problem but there is another connection on pin 5 that goes to the PCM. I assume this is so the PCM can test the fuel pump. I'm not sure if this and the diode could be causing the problem some how.

TEST RESULTS:

Pin 1, 2, 6 & 7 confirm the low speed relay is engaging and not the high speed relay. The 3 volts that dropped off is normal from fan generating V.
All OK

Pin 3, 4 All OK should always be 12V

Pin 5 FAIL see pin 18 results Shows that the fuel pump is running while the fans are running and then shuts off when the fans shut off. OK???

Pin 8, 10 & 11 All OK should always be 12V

Pin 12 OK Power to PCM comes on with switch

Pin 13 OK 12 Volts with switch on

Pin 14 OK? PCM seems to be switching fan on

Pin 15 FAIL? Please tell me this was with meter neg. to bat. neg.
12 V on this pin means you have an open/no ground. You said that you performed all test with black lead to bat neg. except 18. Although if you tested this pin the same way as 18 then it could be OK. Actually you can't test it the same way as 18 because you will measure 12V to bat. Pos. even if the ground is bad because there is a path to ground through the AC clutch coil and clutch coil counter emf diode. Also through the fuel pump and fuel pump counter emf diode if it weren't open (this could also explain diode failure here). Although if you measured Pos. voltage on 15 the diodes could be reversed biased and off (no ground). But if your meter lead was to bat. pos. I probably typed all this for nothing :banghead: Make sure to test to bat. neg.


Pin 17 OK high speed always off

Pin 21, 22 & 23 seem to be OK




Pin 18 TEST: FAIL First with meter to bat. neg.
key off should show 0V OK
key on with fan on .2V OK
key on with fan off 0V FAIL If there's no voltage to pin 5 at this time then the fuel pump relay should be deenergized and you should measure 12V here because of feed back through the relay coil or pullup resistor in PCM drive.

Pin 18 TEST: Meter to bat. pos.
key off: 12 volts inconclusive
key on fans on: 12 volts OK
key on fans finally off: .05 Volts OK

Pin 24 FAIL/INCONCLUSIVE Very suspicious. This is also connected to pin 12 which tested ok. The reason 2 terminals are used on a connector is because the connector is not designed to deliver the needed current through one terminal. Pin 12 showed 12 V though and no voltage drop across the connector. Even if the connector was open on 24; the diagram I have shows another wire that should feed back 12 V to this point. You may have to trace this wiring down. If a retest shows the same results, then do the following: Disconnect connector and measure resistance between 12 and 24 on both the CCRM connector and also between 12 and 24 on the connector that goes to the CCRM and report. Do this with key off.


Rerun the failed tests. If the results are the same it could mean that there is no pos. V to fuel pump relay and low speed fan relay. Could be due to open traces? Pin 17 did show pos voltage though. This could be due to a pullup resistor in the PCM. Try measuring the resistance between pin 17 and 12 and again from 17 to 24 of the CCRM. Both times with connector disconnected and key off. You should get the relay coil resistance if everything is ok. I'm guessing around 100 ohms but should not be 0 and no higher than probably 250.

The fuel pump relay and the low power relays could be running in series during failure due to no pos. V on them. This would explain both of them running at the same time, and quitting at the same time. Bad ground on 15 could also cause a similar problem.

This is assuming all your test results are correct, And I'm not sure how the car starts performing normally after this though.

For the diode you could go to radio shack and pick up a silicone diode. A 2 amp or higher should be fine at around 1KV piv or higher. If you feel capable and replace it yourself be sure to get the polarity right. White stripe on diode to pin 5. If you put it in the wrong way you will create a short circuit to ground.

If the CCRM is messed up bad it might be easier to just get a new CCRM. Not just yet though. Perform a few more tests to confirm and let ROD go over my test analysis.

There also seems to be external problems on the wiring to pin 24.
Not sure about the diagram but what the hell is a "high speed electro drive fan"?

All depends on the test. No offense but some of your earlier tests were a little foggy. The one you did last night seemed to be very good though. Rerun all failed tests just to be sure. If they fail again the same way then do some of the resistance tests that I suggested and post the results.

Hmm, Minnesota isn't too far from Iowa....My sister in-law lives in St. Paul on Portland Ave. and says we don't visit her enough.... :smile:

ROD, were you planning on taking a test meter or a gas can?

Rod, joeh100:

Last night I brought the CCRM module box inside the house to keep it warm. I parked the car outside in the cold temperatures overnight (20 degrees). This morning I connected the CCRM module box back up to the car. The results saw the delay for "those fans to turn off" INCREASE to about 3 minutes ! ! ! !

Usually it's around 5 - 40 seconds.

Does this temperature test eliminate the CCRM module box from being my problem???

This morning I also retested pin-24. Now I get 12 volts at key-on fans on, and 12 volts at key on fans finally off...most of the time. I also got some very low readings similar to my 11/02 post. I am skeptical. I could be having a bad testing day, but I doubt it. I repeated this test this morning about 6 times.

(joeh100, I will review your previous posts and reply with a test plan for your latest requests)

thanks,
Rick

I reran three of the five requested tests during my lunch break today.

Pin-5: inertia fuel shutoff
key off: 1 mVolts <-----same value as previous test
key on fans on: 12 volts <-----same value as previous test
key on fans finally off: 20 mVolts <----this was 10 mVolts on the first test



Pin-15: ground
with red meter lead on battery positive post and testing for DC volts
key off: 12 volts
key on fans on: 12 volts
key on fans finally off: 12 volts

with black meter lead on battery negative post and testing for DC volts
key off: 0.8 mVolts
key on fans on: 44 mVolts
key on fans finally off: 14mVolts

with black meter lead on battery negative post and testing for resistance
key off: 1.6 ohms
key on fans on: 110 ohms
key on fans finally off: 35 ohms

joej100, I apologize for an invalid test that I posted on 11/02/06 for pin-15.
Today’s test for pin-15 should cover all the bases. Sorry about this mishap.


Pin-24: POWER TO PCM
key off: 1 mVolt
key on fans on: 12 volts
key on fans finally off: 12 volts
Pin-24 test results today also were different than what I posted on 11/02/06. I want to say that it’s user error here. Pin-24 should be 12 volts. Whether pin-24 was a good test or bad test, the fans would still run for awhile.


The good news is that I am going to pick up a used CCRM module box in about an hour here. I am going to bring my test meter with and confirm the diode test with pin-5 and pin-15 has a value of .5 ~ .7 unlike my current CCRM module box which is 0.L both ways.

Rick

A lot of thing are different when a car is cold. It has to idle higher for longer to warm up and other things too. This does not really eliminate the CCRM yet.

pin 15 and 24 seem to be ok now.

pin 5 still verifies the fuel pump is running at the same time the fans are running.

Retest pin 18, with meter on bat neg. With the fuel pump relay disengaged you should be getting 12V here. If your not then there's a problem. Also easy to verify with the resistance test I mentioned.
This is the last thing I see that could be causing a problem in the CCRM besides the diode.

Les us know if the new CCRM works though.

The resistance test between pin-12 and pin-24 on the CCRM module box was 0.3 ohms.

The resistance test between pin-12 and pin-24 on the CCRM wire harness was 0.4 ohms.

The resistance test between pin-17 and pin-12 on the CCRM module box was 87 ohms as expected.
The resistance test between pin-17 and pin-24 on the CCRM module box was 88 ohms as expected.

That's all I got for test data. Now here are the results for the spare parts I tried at the local salvage yard.

I tried a CCRM module with the same exact Ford numbers of 101 on the top row, then a big letter R, then F6SF-12B577-AA: nothing improved. The fans still turned on and the car would not start until the fans turned off. The diode test at pin-5 and pin-23 was 0.L both ways on this spare part.

I tried a CCRM module with the Ford numbers of 101 on the top row, then a big letter R, then F48F-12B577-AA: nothing improved. The fans still turned on and the car would not start until the fans turned off. The diode test at pin-5 and pin-23 was 0.7! But nothing improved. :-(

I tried a THIRD CCRM module with the Ford numbers of 101 on the top row, then a big letter R, then F48F-12B577-AA: nothing improved. The fans still turned on and the car would not start until the fans turned off.

Only the very first CCRM module from the salvage yard had the exact same Ford part numbers. The second and third CCRM module from the salvage yard were almost identical to the entire Ford numbers as compared to my original CCRM module....except the first part of the last number was different. I typed F48F as that first part...I am going by memory. The numbers of 101 on the top row, then a big letter R, then F6SF-12B577-AA are the exact Ford part number as found on the original CCRM module.

Well.
Well.
Hhmmm.

I either got three bad CCRM modules............ or it's something else on the car causing problems. This Monday, I am going back to the salvage yard and will be trying to replace my car's computer (PCM/ECM) with one of their spares.

We'll see what happens!

thanks, Rick

Wow, I really expected a good CCRM to fix this, and I would doubt you got three bad CCRMs.

One test from a few posts ago piqued my curiosity:
"Pin-5: inertia fuel shutoff
key off: 1 mVolts
key on fans on: 12 volts
key on fans finally off: 10 mVolts"

This has me wondering if for some reason, when the PCM is attempting to activate the fuel pump to prime the system, the fans are turning on, loading the signal, and somehow setting up an oscillation. Mitsubishi had issues with a bad batch of electrolytic capacitors in their ECMs that would cause goofy things like this. I have not heard of Fords having a similar issue with faulty caps though. But, I'm not working in the automotive industry either.

An electrolytic that is going high in Equivalent Series Resistance (ESR) could set up an oscillation or R-C delay circuit that is quite temperature sensitive though. Such an oscillation would be difficult to detect using a DMM, even on the ACV setting. You'd likely need an oscilloscope to pick it up.

I'll be interested to hear what the alternate PCM does for you. I hope we are not sending you on a completely wild goose (or is it grey duck in MN?) chase.... It would appear that our record is not too good currently.

-Rod

Any batch of components could be bad, but the infamous bad batch of electrolytics out of Taiwan was after 2000 if I'm not mistaken.

Doohhh!!! Here's something I meant to mention earlier. Check the resistance between pin 5 and all fan pins (1,2,6,7) on the connector going to the CCRM (not the CCRM, but wires coming into it with key off). Bad wiring in the harness could actually be connecting the fans to the fuel pump. They are coming off of the same connector. Oh yea, check resistance from all these pins to bat. neg. for comparison. Resistance from (5 to neg.) + (6 or 7 to neg.) should = resistance of (6 or 7 to 5).

He's obviously eliminated the CCRM but what about that bad diode ROD? You think spikes coming from the fuel pump could have damaged the PCM. There is a wire coming off of pin 5 back to the PCM. I'm not sure of it's function but it's probably for testing the fuel pump.

The spikes would of course be high voltage in the opposite polarity. Not very good for electronics. If he puts in a new PCM with the original CCRM and it still has the open diode then it could possibly damage the new PCM.


Some more ideas if the new PCM doesn't work. Again, I'm shooting from the hip now but what the hell.

Do you have diagrams for the fuel pump wiring? Anything else connected there that could have been damaged.

Try leaving the car out and warming the PCM with a hair dryer (not a heat gun) before starting.

I know it tested good but try heating the engine temp sensor before starting also to see if the PCM is actually causing the fans to run related to this sensor. Or put a potentiometer in line here and test the time.

This is really far fetched, but did you disconnect bat. yet. Maybe bad data is causing a flaw/bug in the programming.

We were having numerous issues with bad electrolytics with the Gen 1 Mitsu 3000GT/Dodge Stealth. That was model year 1991 through 1993, so there was a bad batch of caps at least back to the early 1990s.

The fuel pump system is wires, the inertia switch (mechanical switch) and the pump. It is possible that a bad CCRM could contribute to a damaged PCM, or vice versa. That is a good thought.

I'm gonna have to look around to see if I still have my dissected CCRM to see if it agrees with Rick's.

-Rod

Hello again to Rod, joeh100, and others:
I was away for the long weekend. I just got back.

Rod,
I was also wondering "WHY" to the following test results at Pin-5 (inertia fuel shutoff):
key off: 1 mVolts
key on fans on: 12 volts
key on fans finally off: 10 mVolts.

My "WHY" here is why did the voltage drop to 10 mvolts once the fans turned off?, and would the voltage return to the proper 12 volts once the car is started since the fuel pump would need to turn on to continue supplying fuel to the engine?
I am go to assume "yes" to my last part of my question above...but we’ll see after testing this.
I will test Pin-5 again but add one more VOLTAGE test result of "key on/fans finally off/engine running".
key off: 1 mVolts
key on fans on: 12 volts
key on fans finally off: 10 mVolts.
key on fans finally off and engine running: ??? volts

joeh100,
I will run the following resistance tests this evening with key OFF:
1) resistance between CCRM wire harness pin-5 and pin-1 (low electric cooling fan power)
2) resistance between CCRM wire harness pin 5 and pin-2 (low electric cooling fan power)
3) resistance between CCRM wire harness pin 5 and pin-6 (high electric cooling fan power)
4) resistance between CCRM wire harness pin 5 and pin-7 (high electric cooling fan power)
and
5) resistance between CCRM wire harness pin-5 and negative battery post
6) resistance between CCRM wire harness pin-1 and negative battery post
7) resistance between CCRM wire harness pin-2 and negative battery post
8) resistance between CCRM wire harness pin-6 and negative battery post
9) resistance between CCRM wire harness pin-7 and negative battery post

Oh yes, one more tidbit of information. I already tried heating up the ECT sensor with a hair dryer to see the effect it had on the "delay time for the fans to turn off" - it had no effect. I also put the hair dryer in the air intake tube (where the air filter is found) and supplied very warm air up into the air intake into the motor - it had no effect on the "delay time for the fans to turn off".

I did try heating up the PCM on another test which had no effect. However, it seemed like the heat really could not get to the "smarts" of the PCM itself. Just the wire harness is all I could get at to warm up. Therefore, I am going to take the PCM out one night to see if it has a confirmed effect on the "delay time for the fans to turn off".
I will conduct this test by 1) disconnecting the negative and positive lead on the battery, 2) disconnecting and removing the PCM, 3) keep the PCM warm in the house, 4) reinstall the PCM the next morning when it’s cold out, 5) connect the positive and negative lead on the battery, 6) and turn the key from "off" to "on" and see what happens to the delay time. Right now it has gotten back to 50 degrees again. The delay is only 7 - 9 seconds. I will need to wait until the temperature gets colder, let’s say to around 20 degrees, before I can do this test. The delay at around 20 degrees can be up to 2 or 3 minutes!!!!.
Once I run this test and the delay is only 7 - 9 seconds, then I’m assuming the PCM is the problem.
or
if the delay is still long from around 40 seconds to 2 minutes, then I will assume the PCM if fine, and then I will test all the positive and negative inputs at the PCM itself to see which one is not showing up at when I turn the key from "off" to "key on".

Thanks again for everyone’s time for helping, and also the EXTRA STEPS trying to avoid damaging any new components that may be placed into the overall picture. Rick

Hey, Rick. Did you ever order the CD manual off of ebay? If so what did you think of it? I'm thinking of ordering one for my car.

Hello again to Rod, joeh100, and others:
I was away for the long weekend. I just got back.

Rod,
I was also wondering "WHY" to the following test results at Pin-5 (inertia fuel shutoff):
key off: 1 mVolts
key on fans on: 12 volts
key on fans finally off: 10 mVolts.

My "WHY" here is why did the voltage drop to 10 mvolts once the fans turned off?, and would the voltage return to the proper 12 volts once the car is started since the fuel pump would need to turn on to continue supplying fuel to the engine?
I am go to assume "yes" to my last part of my question above...but we’ll see after testing this.
I will test Pin-5 again but add one more VOLTAGE test result of "key on/fans finally off/engine running".
key off: 1 mVolts
key on fans on: 12 volts
key on fans finally off: 10 mVolts.
key on fans finally off and engine running: ??? volts

Yes, if anything is going to make sense here, you'll have to see +12V on pin 5 with respect to ground when the engine is finally running. If you have access to an oscilloscope, this would be an interesting signal to scope out.

-Rod

joeh100, Rod:

Here are the latest test results.

DC voltate test for Pin-5 (inertia fuel shutoff) with the black meter test lead connected to the negative battery post:
key off: 1 mVolts
key on fans on: 12 volts
key on fans finally off: 10 mVolts.
key on fans finally off and engine running: 12 volts <------- looks good !!!!!!!!!

Rod, I believe Pin-5 above is showing the correct voltage........right?


With key OFF:
1) resistance between CCRM wire harness pin-5 and pin-1 (low electric cooling fan power) was
1.8 ohms
2) resistance between CCRM wire harness pin 5 and pin-2 (low electric cooling fan power) was
1.8 ohms
3) resistance between CCRM wire harness pin 5 and pin-6 (high electric cooling fan power) was
1.1 ohms
4) resistance between CCRM wire harness pin 5 and pin-7 (high electric cooling fan power) was
1.1 ohms
and
5) resistance between CCRM wire harness pin-5 and negative battery post was 0.9 ohms
6) resistance between CCRM wire harness pin-1 and negative battery post was 0.6 ohms
7) resistance between CCRM wire harness pin-2 and negative battery post was 0.6 ohms
8) resistance between CCRM wire harness pin-6 and negative battery post was 0.4 ohms
9) resistance between CCRM wire harness pin-7 and negative battery post was 0.5 ohms.

joeh100, I really am unsure what results would be favorable for the above 9 tests. Let me know what this outcome means when you have time.

joeh100, you asked about the cd manuals of ebay. Well, if you want tons of information to read, study, learn, reference, print, get lost with, data overload...then I easily say without a doubt these cd manuals kick @$$. I just got mine today. They are loaded with tons of information, pictures, diagrams, pin-outs, testing steps, troubleshooting trees, etc. Plus all this information is for electrical, mechanical, emissions, etc. I cannot say enough about the cd manuals. They go in great detail too. I got mine for only $4 each. I got one for my 1997 Taurus and my 1995 Ford F150. When I searched eBay for these cd manuals, I got lots of sites selling these cd manuals. I will find my order information tomorrow and let you know which merchant I dealt with.


Back to the Taurus starting mystery. I am thinking that with the warm weather again, I won’t be able to conduct my "car outside in cold weather and pcm inside in warm climate" test very soon. Therefore, I will probably go back to the local salvage yard, and search for a 1997 Taurus GL pcm with the same calibration code. I can try it on the spot for a very small fee. It’s worth our time to try this.
Could you guys get back to me by Friday if my car could possibly damage another pcm or not with what we have tested so far?


I don’t mean to talk (type) anyone’s ear off, but I have been thinking (and learning) about my car and how to summarize the past weeks of testing.
Other people have said to replace the CCRM to "fix the fans and have the car be able to start again"...I believe them that a new CCRM solved their problems because in their case, the PCM relay was probably bad in the CCRM, therefore no power was supplied to the PCM which meant no PCM involved in the picture and this would cause the fans to turn on, and car not to start neither. Remember, the fans will run if the PCM harness is disconnected (or with no working PCM at all in the picture).

Yet other people have said to replace the PCM to "fix the fans and have the car be able to start again"...I believe them that a new PCM solved their problems too because a bad PCM won’t do its thing and with no PCM involved in the picture, this would cause the fans to turn on, and car not to start neither. Remember, the fans will run if the PCM harness is disconnected (or with no working PCM in the picture).

In my case, I have:
1) no injector pulse signal while the fans are running
2) no spark at the spark plug while the fans are running
3) no difference with the CCRM brought into a warm house overnight last week when it was cold
4) pcm power leaving the CCRM and going to the PCM while the fans are running
5) absolutely no OBD-II communications to my data scanner while the fans are running.
6) the car is eventually still able to start; the car is not a "no start condition" because the car will eventually start, and once started it runs fine.
I do not want to focus our attention on the part that says "while the fans are running"...it’s just that the fans are a great indicator when, I believe, the PCM decides to all of a sudden show up in the picture for some reason and do its thing (supply a signal to the fan relay in the CCRM thus turning the fans off, supplying injector pulse signal and spark to the spark plugs thus allowing the car to start easily, and supply all kinds of OBD-II data to my scanner).

So to finish here, yes I will stop typing, I either have a:
A) bad PCM
or
B) bad or missing signal from the car that is not getting to the PCM which is preventing the PCM to come to life or "turn on"...and by "missing signal" I mean a missing power or missing ground signal into the PCM.

How’s that for a summary of what has happened so far?
thanks, Rick

Thanks for the info on the CD's. I will definately be ordering one.

Your test seems to indicate no problems with external wiring from CCRM in the fuel pump or cooling fan wiring. There is a .3 ohm discrepency though. Can you disconnect the plugs at the cooling fans and measure the resistance from pin 5 of the CCRM to pins 1, 2, 6 & 7 again just to be sure. With the fan plugs disconnected your meter should show OL with all of these tests.

Assuming the above does show OL then I would say there are no problems with the CCRM (except the diode, did you fix this yet) or the external wiring or components after the CCRM. Your problem would have to be with PCM or inputs to the PCM.

The PCM does drive the ignition and the fuel injectors directly doesn't it. There are no external modules between them are there?

There is a rare case in electronics where you have to replace 2 components at the same time. If you don't one could damage the other and vice versa. I wouldn't worry about this just yet. Assuming you don't have an O'scope, I would pay the fee you mentioned and test with the new PCM. A bad PCM was my original "guestimate", but I have to admit I am perplexed by your problem.

Good luck, and if all else fails you may want to reconsider my plan for insurance fraud. :evillol:

I have a concern though with the idea that having the PCM unplugged, the fans still run. Are you able to tell if the fans are running in high or low speed? Did you perform this check with any of the other "spare" CCRMs to see if they cause the fans to run with the PCM unplugged? I would suggest checking that before trying a "spare" PCM. The high speed fan relay is driven directly by the PCM. The low speed fan relay is controlled by a solid state controller which is controlled by the PCM. About the only way either fan could run with the PCM disconnected is if one or both relays are faulty and sticking closed for some amount of time, or there is a wiring issue between the PCM and the CCRM. If the low speed fan is running, then a faulty solid state relay controller inside the CCRM could also cause the issue.

As joeh100 eluded to before, this could be a case of two bad components, the CCRM and the PCM. Sort of a chicken or the egg scenario though. If the PCM caused the CCRM to fail, then you may now have three bad CCRMs.

It would be nice if you could find a good friend with a 1997 Taurus. Get a fresh CCRM and install on the working Taurus. If it works there, then tried a "spare" PCM on their car. If that also works, swap them both into your car.

Also, if you are friends with a local shop or dealership, see if you can get your hands on a breakout box for the PCM. This will allow you to monitor the inputs and outputs without cutting wires to the PCM or pulling terminals from connectors.

-Rod

Rod,

I did not check for low fans -vs- high fans at all.
I did not disconnect the PCM during any of the three other CCRM's.
I do not have a friend with a 1997 Taurus nor an opportunity for a break-out box.

I'm 0 for 3 here. :-(

Maybe if I can get lucky where a different used PCM solves everything (no fans, no delay in starting) then I'll stop and purchase that PCM.

Otherwise, I will wait for cold weather again so I can try my test of bringing into the house the PCM itself overnight to keep it warm while the rest of the car sits outside in the cold weather.

If that doesn't prove anything, then maybe I need to bite the bullet and purchase a new PCM at my local Ford dealership ($280) and pay the 1 hour of labor ($75/hour) to install/flash the PCM, and at the same time also purchase a new CCRM ($150) at the same time. Installing the PCM is simple, I just don't have the ability to program/flash the new PCM...so I'm stuck going to the local Ford dealership...a.k.a. local Ford stealership. I also will be left with a good enough spare CCRM for any future Relays going bad (fuel pump, a/c, pcm, fans) that are not related to my current issue.

How's that for a plan?

Actually, since the PCM might be damaging the CCRM, I could probably just purchase the new PCM and see what happens. The CCRM cannot be damaged anymore at this point anyway. I could always then purchase the CCRM if needed. This is relying on the fact that the current CCRM could not damage the new PCM.

joeh100, I will still follow through with our latest test ideas with the fans disconnected too.

Thanks.

joeh100,

I got 0.L for all the tests as you had requested with both fans disconnected.

I also brought the PCM into the house and placed it into the refrigerator overnight. It will be VERY interesting if the delay comes back or not.

Wait, I didn't know the fans were still running with the PCM unplugged. Was this with the PCM connector unplugged or with the CCRM connector unplugged?

Based on your earlier tests it is the low speed that is activating.

With the connector unplugged do the fans run constantly or do they shut off like normal after an amount of time. If they shut off after a certain amount of time and the PCM is unplugged then this totally eliminates the PCM. That would be good news. But, if they run constantly this could be normal if the relay driver has it's own pullup resistor.

You could test by breaking the connection to the PCM and tying the #14 wire to either + or - on the bat. One shoud make the fan run and one should make the fan go off. You should probably put a resistor in line (1K ohm) to be on the safe side though, because we don't have enough info on the relay driver. If it doesn't work with the resistor then it is probably safe to go direct. You should make sure the PCM is disconnected.

I just noticed something else very interesting. The fuse symbols are not all the same on the diagram. Some of these aren't automatic reset circuit breakers are they? That's definately worth checking out.

joeh100

Wait, I didn't know the fans were still running with the PCM unplugged. Was this with the PCM connector unplugged or with the CCRM connector unplugged?

To answer this: the fans run when the PCM wire harness is disconnected from the PCM itself while the CCRM is still connected. The fans do not run when the CCRM is disconnected.


With the connector unplugged do the fans run constantly or do they shut off like normal after an amount of time. If they shut off after a certain amount of time and the PCM is unplugged then this totally eliminates the PCM. That would be good news. But, if they run constantly this could be normal if the relay driver has it's own pullup resistor.

To answer this: I disconnected the PCM only to confirm that the absence of a PCM (or the absence of a PCM signal to the CCRM) that the fans turn on and stay on...which they did with the PCM disconnected. I did not run this test for a long period of time to see if the fans would turn off.


You have mentioned to disconnect the PCM, then connect pin-14 on the CCRM to battery + or battery -. Is this with the CCRM disconnected too?

When you talk about resistors, 1 k ohm, automatic circuits, breakers...I don't understand that stuff. Sorry about that. Remember, I am the pit gopher here and you guys are the intelligence behind the plans. :-)

Rod, joeh100:

This is interesting. The temperatures have been warm here lately for me to test by leaving my car outside/pcm inside the house. So, what I did instead was leave the car in a warm garage, and put the pcm in a 20 degree environment inside the house. This morning I quickly connected the PCM back into the car, and the DELAY TO START THE CAR WAS QUITE LONG...about 40 seconds!

I will confirm this by leaving my car outside in the cold temperatures when they arrive, and bring the PCM in the warm house overnight. I am willing to bet that there will be a very, very little delay starting the car.

So, I'm thinking at getting a new PCM. Should I get a new CCRM too? I am thinking I do not need to get a new CCRM too unless the schematics show a way that the CCRM could damage the new PCM. Any input on this?

joeh100, Let me know if I should test pin-14 to battery + and battery - without using a resistor.

Tomorrow, I will be going to a local salvage yard, and try to find an OEM PCM for my car with the same part #: F7DF-12A650-EB with NXZ1, and the calibration #: 7-10B. If this used PCM works...great. I'll just buy it...DONE. If I can't find a PCM that works out, then I feel I would/should go with a Ford OEM PCM since this is a critical part of the car.

I see online that some PCM's can be ordered with the correct flash, but the same website states that the VIN number needs to be programmed at time of install. Not sure what this is all about, but I will let the Ford dealership install and program a new PCM (if I can't fiind an OEM PCM).

Thanks.

To answer this: I disconnected the PCM only to confirm that the absence of a PCM (or the absence of a PCM signal to the CCRM) that the fans turn on and stay on...which they did with the PCM disconnected. I did not run this test for a long period of time to see if the fans would turn off.


This is a very important test. If the fans shut off after a while like they normally do then this totally eliminates the PCM, But if the fans never shut off then this could be normal since they have no control signal.

You can pick up a 1K ohm (1/2 Watt) resistor from Radio Shack. Just ask the nerd behind the counter. You may also want to pick up a set of gator clips leads, they can come in handy when troubleshooting.

I will confirm this by leaving my car outside in the cold temperatures when they arrive, and bring the PCM in the warm house overnight. I am willing to bet that there will be a very, very little delay starting the car.
If this test confirms your previous test then it sounds like problem solved. You may want to still do the pin 14 test to confirm proper CCRM. Also get the diode replaced if you haven't so far.

After about 100 posts, the "fridge" test seems to have nailed it down. Damn good idea if you ask me. Wish I had of thought of it.

joeh100,

If the diode is NOT fixed before I install the new PCM, can the CCRM that contains this bad diode damage the new PCM?

The tests I will conduct this evening:

1) disconnect PCM wire harness, leave the CCRM connected, turn key "on" which will cause the fans to turn on...and wait several minutes to make sure the fans continue to stay on

2) I will buy a "1K ohm (1/2 Watt) resistor from Radio Shack", disconnect PCM wire harness, leave the CCRM connected, key "off", and jumper wire-14 to battery (+) and battery (-) to confirm turning the fans off and on.

joeh100, please confirm if I got the test steps correct... and also about the possibility if the bad diode can damage the new PCM.

Thanks again.

Rick

A note of caution on the pin 14 test. It is unclear what level the solid state relay controller is expecting, battery voltage or logic level such as 5V or maybe even 3.3V. If you limit the current with a resistor such as 1k, you'll probably be okay, but by all means don't attempt to connect that straight up to the battery. I agree with the recommendation from post #80.

I would expect that Ford conformal coats the PCM and CCRM, but if not, it would interesting to reflow all joints, or at least any that appear suspect, to see if that fixes anything.

When I purchased my 1998 Taurus SHO, I found after a couple weeks that randomly the radio head unit backlighting would shut off. The radio continued to work and the display was fine, just the button illumination went out.

I opened the deck up and inspected the solder joints and traces under my magnifying light, nothing obvious. I traced the illumination circuit and reflowed all joints, even though none looked suspect. I never had the solder pull away from the joint as is common with cold joints, but for 2 years afterwards, I never had another illumination issue. Must have been a cracked via/feedthrough somewhere I suppose.

-Rod

Assuming a BJT is driving the relay then a 1K ohm resistor should limit the current to about 13 mA. If however, the driver already has a current limiting resistor this may not even work. It's hard to say without having access to the CCRM. Did you see if the fans continue to run with the PCM disconnected. That should mean that everything is OK.

Anyway, connect one side of the resistor to pin 14 and the other side to the bat. Make sure the PCM is disconnected.

I wouldn't chance a new PCM without replacing the diode. If you take the CCRM to Radio Shack and show them the diode then they may replace it for a small fee. It really depends on the Radio Shack though. If you have an Amateur Radio club in your area they would probably solder in a new diode for free (if you supply it) and maybe even retouch all the joints for a small fee.
If the board has conformal coating, acetone will cut right through it (If it's not silicone based).

Sounds like you might be treating the symptom and not the problem. I ran into a similar situation with the CCRM on my Taurus. Swapped several CCRM and other components without a change in behavior. I ultimately discovered a bad ground between the CCRM and the frame. (was a bad ground plug that terminated on the frame right next to the CCRM!!). The current drop caused the multiple relays to chatter (whirring sound) and prevent the fuel pump and PCM from energizing. Do a wiggle test on the numerous ground lines in the car while running and see if the engine reacts...if so, you've found your problem. Hope this helps!

Pishmael, thanks for the ideas.

You had stated
Sounds like you might be treating the symptom and not the problem. I ran into a similar situation with the CCRM on my Taurus. Swapped several CCRM and other components without a change in behavior. I ultimately discovered a bad ground between the CCRM and the frame. (was a bad ground plug that terminated on the frame right next to the CCRM!!).

Correct me if I'm wrong, but I've "hopefully" eliminated the possibility of a bad ground to the CCRM by the following:
I checked for resistance between Ground Pin-15 which seems to be the only ground for the CCRM and the frame of the car and got the following (see post #31):
key-off: 0 1.9 ohms
key on fans running: 110 ~ 140 ohms
key on fans finally off: 22 ohms.

and

I jumpered a wire from the battery negative post onto the wire going to pin-15 at the CCRM.

and

I do have fuel pressure too.

None of the above tests/experiments prevented the fans from turning on when the key was turned from "off" to "on".

Would you agree the above could eliminate a bad ground problem such as yours?

Thanks.

joeh100,

Here are the results from the latest two tests.

1) disconnect PCM wire harness, leave the CCRM connected, turn key "on" which will cause the fans to turn on...and wait several minutes to make sure the fans continue to stay on

2) I will buy a "1K ohm (1/2 Watt) resistor from Radio Shack", disconnect PCM wire harness, leave the CCRM connected, key "off", and jumper wire-14 to battery (+) and battery (-) to confirm turning the fans off and on.

Test 1 had the fans running continuously for many, many minutes.

Test 2 did not turn the fans on when wire-14 was connected to either battery (+) or battery (-) while using the resistor inline. The fans stayed off the entire time during Test 2.

About your comment of replacing the diode in the CCRM...well...I have no idea what component on the CCRM board would be the diode that needs replacing. I will take the CCRM apart this weekend and trace pin-5 onto the circuit board and see what I find. What does a diode look like to begin with?

I feel very confident soldering any component to a circuit board as I have done so many times in the past...I just need to find out what part to replace. :-0

Thanks.

The diode will most likely be a small black cylinder with a white or silver band around the circumference on one end. The leads will be axial (one out the top of the cylinder, one out the bottom). The diameter of the cylinder will probably be around 2 mm.

The circuit board will most likely be at least 2 layers so you need a decent soldering iron and good desoldering braid to avoid overheating the pads and causing them to lift. If you have a small hand drill, you may be best off cutting the diode off of the board, then trying to desolder the remaining leads or just drilling them out, then installing the new diode in the proper polarity/orientation. Once you have the diode out of circuit, test the diode again as well as pins 5 and 15 of the CCRM to make sure the diode was the issue.

-Rod

The diode will likely look like the component at the following link:
http://www.mcminone.com/product.asp?catalog%5Fname=MCMProducts&product%5Fid=N%2D94B7157

-Rod

Rick, on your earlier post, did you perform test 2 with the key off? The switch would have to be on to do this test. However test 1 seems to show the fans run continuously, which means the CCRM is most likely fine.
BTW you can reuse those resistors. Just solder to an LED for a test light.

The link that Rod provided shows a price of 8 cents for a diode. Don't expect that from Radio Shack LOL.

If you don't have good soldering skills then the hardest part of replacing the diode will be removal. The easiest way is to cut one lead on the diode. Next heat the joint while pulling slightly on the lead with pliers. Either use a little flux or apply a little solder during removal to get the joint to flow quickly without over-heating it. If you use desoldering braid from Radio Shack then apply a small amount of solder to get things flowing. Their braid doesn't contain flux. You could also cut the leads and then solder the new diode directly to those leads (quick and dirty, but effective). Make sure you remember how the original was oriented before removing it though.

Also as Rod mentioned, test the original diode in circuit before you do anything.

joeh100, Rod, others:

I found the only PCM out of 20-some in the entire salvage that was compatible with my original PCM. I installed it in my car on the spot, and the car had no delay starting ! ! ! ! ! (and no fans were running that I had to wait for neither). Hoo-ray ! ! ! ! ! !

I guess we finally have our answer to this saga! ! ! ! !

Most people would stop here and call it a day. Well, per your recommendations I have decided not to chance my good used PCM that I bought today with the old CCRM still in place because of the diode being questionable. In the meantime, I have taken out the GOOD used PCM that I bought today, and placed the original PCM (the PCM with the delay) back in the car.

I ran my car for about 15 minutes with the good PCM today before taking it out. The good used PCM still worked fine prior to taking it out, however, do you think any amount of damage may have occurred anyway? Just playing it safe and wondering.

This weekend my next step(s) is:
try to locate a CCRM where the diode test between pin-5 (inertia fuel pump) and pin-15 (ground) shows something other than 0.L.
- and/or -
take apart my CCRM this weekend and see if I can find "that diode" to replace that you guys are describing.

We have been at this for two weeks...why stop now! :-)

T H A N K S .... A G A I N !

Yippie!!! More good progress! This could be a great reference thread in the future.

There is a chance the new PCM could have been damaged by the fuel pump turning off, but I would HOPE that the PCM has some redundant protection for that. In the interest of saving money though, probably not.

However, since you only had one or two cycles of shutting off the engine with the good PCM, the amount of damage should be minimal. Like ESD damage though, degradation could occur and cause a latent failure, but that could be 10 years from now, assuming you fix the diode or find a good CCRM. Plus, if this acts up again, you'll have a good idea on where to start looking. :)

Congratulations, and thank your for your patience.

-Rod

Yippie!!! More good progress! This could be a great reference thread in the future.

"1001 Ways to Test Your CCRM" :)

I took apart my CCRM. I traced pin-5 onto the board. I found it confusing where pin-5 leads to on the board. I could not confirm the diode for pin-5. I did find two diodes total for the entire board. I tested both and one had 0.6 for a reading and the other had 1.3 for a reading. Now I'm really confused.

Question 1: shouldn't I find a diode with 0.L as a reading at the circuit board location like I get when I test at the pin-5/pin-15 locations?

Question 2: could the diode that I am seeking be in the relay itself?

Here's an interesting fact. The PCM that I found to solve my problem this past weekend came out of the same car that earlier (about two weeks ago) I retrieved a CCRM out of...this same CCRM with the same Ford part numbers also tested 0.L at pin-5/pin-15.

I plan on looking for a used CCRM until I found one that tests well at pin-5/pin-15 before buying it, or just ordering a new CCRM.

Thanks.

You can use your continuity test function of your DMM to verify if the diode you are seeing on the board is the diode for pin 5 to pin 15. The diode for those could also be a switching diode (the link I sent you earlier is a rectifier diode). A switching diode will be in a translucent red case with a black band to designate the cathode. See the image at http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=1N4148&CFID=1701335&CFTOKEN=79533117

-Rod

Rod, joeh100,

I just found another identical Ford exact part# CCRM today about an hour ago. I did the pin-5/pin-15 diode test, and I still get 0.L and 0.L.

That is three "used" identical Ford exact part# CCRM's that all tested the extact same at pin-5/pin-15 via the diode test. Are we sure there is a diode that should show 0.5 ~ 0.7?

The diode could be at the fuel pump itself and not the CCRM for your car. Depends on if the diagram we're usising is correct.

The diagram that was e-mailed around is from the factory Ford service manual for the 1997 Taurus. It should be the correct one. The diagram clearly shows the diode internal to the CCRM, but the diagram is not a schematic, but rather a detailed block diagram. There could be other components in the circuit I suppose that causes the OL reading.

Taurus1997, any chance you could take a couple photos of the top and bottom of the opened CCRM and post them or e-mail them to us?

It's probably safe for you to install the CCRM with the new PCM and drive the car in the mean time. :)

-Rod

Taurus1997, any chance you could take a couple photos of the top and bottom of the opened CCRM and post them
Yes this could help a lot.

I have no problem getting a good detailed photo on the top and bottom of the CCRM board. Thanks for the idea.

In the meantime, I have a question about trying to locate "that diode" for pin-5. I will look for the other kind of diode that Rod listed as a "switching diode". Can I be certain I am at the right diode (whether it’s a diode or a switching diode) when I simply use a continuity check with my meter from pin-5 and to either side of the diode that I am trying to locate? Is it that fool-proof? I would also like to know this for future reference too.

If it’s that fool-proof, I can find "that diode" by checking from pin-5 for continuity to every diode possible on the board until I FIND continuity to a particular diode AND the diode then tests 0.L both ways. I will THEN know I found the right diode to replace. Does this sound like a good plan?

Thanks again.

You can use a meter to check the diodes but just make sure they aren't crystal diodes or the meter will destroy them. I wouldn't think Ford would use crystal diodes though. You'll need an oscilloscope to test crystal diodes. THIS (http://www.allaboutcircuits.com/vol_3/chpt_3/2.html) web page will help to explain the general testing procedure. Just remember that diodes are basically one way gates for electricity. You should get a reading one way but not the other (usually at a ratio of 10:1).

Before we get too far with crystal diodes (oh no), could somebody answer if I'm correct about my diode location/testing theory in the previous post/thread #100. I would like to know so when I take apart the CCRM tonight to take pictures of it...I can possibly also hunt down the suspect diode at the same time.

And about crystal diodes...what do those look like?

I will post the pictures tonight too.

thanks, Rick

Can I be certain I am at the right diode when I simply use a continuity check with my meter from pin-5 and to either side of the diode
This all depends on whats between the diode and pin 5. Would need a schematic of the circuit to know for sure. If you are just testing the diode then pin 5 shouldn't be needed, as you're just testing the diode itself. Don't worry about the crystal (Germanium) Diode. Most likely they won't be used, but they are very small, usually less than 1/4'' long.

Rick, yes, using the continuity function to determine the correct diode is fool-proof, as long as you watch the resistance when you hear the continuity buzzer. If, for instance, you found continuity to a diode and the resistance from pin 5 is a few ohms, you may be measuring continuity to another diode through a relay coil. According to the detailed block diagram from the service manul, that should not be the case if the CCRM is unplugged from the wiring harness.

If measuring from pin 15 though, you may measure continuity to the diode across the PCM relay coil.

If you find a diode that measures continuity between one lead and pin 5, and the other lead to pin 15, you can rest assured that you have found the correct diode.

-Rod

...but just make sure they aren't crystal diodes or the meter will destroy them.
Where did you hear that using a meter to test a germanium diode will destroy it? I've never heard that, and have tested numerous germanium diodes without known failures (possibly latent failures, but never had one come back). I'd like to be aware of this for the future, but want to check the source before I change my ways.

FWIW, the link you posted does not warn against testing germanium diodes. In fact, it mentions what to expect for a reading when testing them with a meter.

-Rod

Where did you hear that using a meter to test a germanium diode will destroy it?
Well maybe 'destroy' is not the best word to describe it. What happens is that it completely ruins the diodes sensitivity, basically making it a wrong part for that circuit. This is especially important when testing radar circuits. It's a fairly well know testing procedure. I'll see if I can find anything regarding it on the net for you :)

Well I found this (http://www.tpub.com/content/neets/14188/css/14188_68.htm) for you. Notice the last line of "Testing Diodes with an Ohmmeter" it says "NOTE:This test should never be used to test crystal mixer diodes in radars. It will destroy their sensitivity." and right under that is says: "An oscilloscope can be used to graphically display the back-and-forward resistance characteristics of a crystal diode."

If I find more on line I'll post it for you :)

Interesting, thank you for the link. I guess I'll have to remember to use my Fluke 199C from now on to test any germaniums I come across.

-Rod

Ooops, now that I've looked at diagram 2-15 in the link you posted, it looks like I should have kept my Tek 454 scope. I don't think the Fluke has horizontal and vertical inputs.

-Rod

Is it a B series or a C series?

Hey everyone:

I said I would post pictures of the CCRM this evening....how do I? I got some really nice detailed pictures. The bottom left of my web page says "you MAY NOT post attachments". What do I need to do to change this so I can post attachments?

Thanks.

Go here (http://www.imagecave.com/) and upload the pictures. It is a free site. Then you just copy and paste to have pic here. Just copy the EZ code.

http://usera.imagecave.com/way2old/Sheriffcar.jpg

Is it a B series or a C series?

The Fluke or the Tek? The Fluke is a 199C (2 channel color, 200 MHz BW, and the software to go along with it). :)

-Rod

Yeah that is one suh-weet scope/meter :) I thought I read where the new B series has those inputs but I'm not sure about series C. I don't allow myself to read too much about those scope meters because I tend to drool to much on my keyboard :p

Here are the four pictures of my CCRM.

The first picture shows the bottom side of the CCRM circuit board.
The next two pictures show the same top side of the CCRM circuit board.
The last is simply the cover for the CCRM.

I have placed a RED ARROW in each picture where I have confirmed continuity between pin-5 and that particular place on the CCRM circuit board.

This should be interesting what is diagnosed here.

http://img1.putfile.com/thumb/11/31910084484.jpg (http://www.putfile.com/pic.php?img=4004807)

http://img1.putfile.com/thumb/11/31910084476.jpg (http://www.putfile.com/pic.php?img=4004806)

http://img1.putfile.com/thumb/11/31910084362.jpg (http://www.putfile.com/pic.php?img=4004805)

http://img1.putfile.com/thumb/11/31910084317.jpg (http://www.putfile.com/pic.php?img=4004804)

Thanks.

Those photos are very beneficial! It would appear that the diode between pins 5 and 15 was not included (D8). The diode symbol and reference designator D8 definitely indicate this would be for a diode. Have you checked for continuity from the corresponding D8 pin to pin 15? On the component side of the board, the corresponding pad appears to be on a ground trace, which is the function of pin 15, so I'm quite confident that you will have continuity to pin 15. This would indicate that D8 is the diode that shows up in the block diagram, and for whatever reason, was not included in your version of CCRM.

If you want to confirm that D8 would be the suspect diode, check for continuity between one of the four large solder connections for the K2 relay (connections on the underside of the board) to pin 11 and one to pin 18. If all these measurements checkout fine, then your CCRM does not include the diode we've been discussing in the thread on the forum. There are two possible reasons for this, either the diode was left off by accident, or the diode was intentionally not installed. I would expect the latter since at Ford, Quality is Job #1. ;)

If the replacement PCM came from the same donor car as one of the PCM's that you also have as a spare, make sure to use the two as a matched set. It is possible that, as joeh100 mentioned before, the diode has been incorpated into the PCM. If the donor PCM is of a different part number or revision than what you removed from your car, then you should use the CCRM from the same car to be on the safer side.

Thank you for providing those photos!

-Rod

Rod, joeh100, others:

Thanks for ALL your help and time solving this vehicle starting problem. It was nice finding people that would offer their time to help others. I learned A WHOLE LOT too about car diagnostics, testing, and troubleshooting. Taurus1997.

I learned A WHOLE LOT too about car diagnostics, testing, and troubleshooting.
That's probably the most important part!

And this thread may possibly help others understand why sometimes when they take their car to a shop for service, it takes longer than initially expected to properly diagnose a symptom that seems rather trivial in the beginning.

For many shops, it's a catch-22. If they shotgun an electronic part and it doesn't fix it, they are stuck paying for it and keeping it on their shelf. Or, if they send the car out the door thinking it's fixed, when really the symptom just chose not to exhibit itself at that moment, the customer will be irate that they just spent $600 on a repair that didn't fix anything. If they properly troubleshoot the problem, the customer bad-mouths them for taking 4 or more days to find the problem. In the process of troubleshooting, they may run into parts that don't seem to match the information from the factory service manual, and as you realized, the CCRM is not intended to be taken apart.

An automotive technician would have a very hard time determining that the suspect diode was not actually installed in the CCRM, unless they were willing to eat the cost of a potentially good part.

I've been on the technician side of that story, it's not fun! I much prefer my current job where I can admit to my boss blowing up a $65,000 piece of hardware and just be told, "Try to be more careful next time" or "Write a procedure to make sure that doesn't happen again." :)

-Rod