No power to the CAS on a 91 talon.

Ok here is what i have got so far. I tested the coil it cam out good. Tested the ignition resistor by it and it came out good. Tested the conector for the cam/crank sensor and there is no 12vB+ on the the number three pin and no 4.8 to 5.2v on the 2 pin. So would it be that the ecm is junk? I am at a total lost of what to do. I have enough mechanical skills with these but the tsi I have never played with. So could some one help please.
Thanks
Shawnn

The ECU won't fire the plugs unless it receives feedback from the CAS. Does your CEL come on for 5 seconds when you start the car? Does the boost gauge move to the zero position with the key is "on"?

Since it's a 1g, I would pull the ECU just to check for leaking caps. It's not hard to do and it's a very common problem with 1g's. But it sounds like a dead CAS to me.

The check engine light does not come on at all. The only lights that come on are batt, seat belt, oil light, and what I believe is the low coolant light. If I remember the low coolant one looks like the a house with vertical lines in it.

Even if you don't think your car is throwing codes your CEL should still come on for at least a second or two when you first insert the key and go to crank it over. If not , could be a dead bulb or someone may have tampered with your cluster.

For spark issues - seems like a CAS is a common issue then again..unsolid capacitors leak like a mofo after time and eventually take out the entire circuit board...I used to have a 1992 dodge stealth..same shit.

Ok well here is another thing to add to this I did the power test to get a possible read out for fault codes. There was no power at the port to do it with the non digital multi meter. I used the number 1 and 12 pin like the book said and nothing. I talked a mechanic buddy of mine and he said the same thing as I did about the ECM. Go figure ya know. But I bought for good deal and project car.

I figure 800 for the car was a steal. It has a 3" stainless exhaust, aftermarket turbo tubes, K&N filter, walbro 255 fuel pump, cross drilled and slotted rotors. This car will be fun.

For the life of me I can not figure out why i am not getting power to my cas. :banghead: I checked for power at my plug next to the CAS and nothing. Possible ECM or what??? Please help.

I just checked two minutes ago the power that cas is getting is all in negitve power feed. so pin 4 in 10v neg, pin 3 in 10v neg and pin2 is neg 10v. Pin 2 is suppose to be 4.8 to 5.2 positve voltage and Pin 3 is suppose to have 12 volts positve!

I have negitive power on 3 of the four terminals on the plug that goes to my CAS. I had the ecm plugged in and unplugged and it shows negitive power. So what power the CAS? If it's not the ecm what do I need to replace on this car? I need this car running soon. Before I forget this is on a 91 tanlon tsi awd 5 speed man.

Shawnn

Pin 1 (white) is cam signal to ECU pin 22, pin 2 (black (small))is crank signal to ECU pin 21, pin 3 (red wire) is 12 volts supplied by the MPI relay (pins 4/5), and pin 4 (black (large))goes to ground number 7 which is the ECU ground at or near one of the ECU mounting bolts.

I would expect to see 12 volts on the red wire/pin3 with the key on, zero volts on the ground wire obviously, and zero volts at the other two pins probably or maybe 5 volts, hard to tell. I can check my car tomorrow.

There it is on a silver platter, hopefully it helps. ;)

Whoa!! I'm seeing double...

There is no "negative voltage" on these cars, try swapping the leads on your meter.

Whoa!!! I'm seeing tripple now!

Geez... How many damn threads do you need for this?... I'm merging them all together... There is no need to make so many for the same topic. Chill out on the post button next time and just wait for someone to get on and reply to your question when they see it... It's not like we are on here every day to check or something...

sorry for multi posting. I know how to use a multi meter. I have worked on many types of cars. Flipping the lead ends around shows no power to the cas. Everytime I look at this you all tell me it's the cas not the ecm. The cas recieves its power from the ecm. I have talked to a few other dsm certified mechanics and they say the same thing. The place were I will be getting the ecm from is motoguys garage. There site says the same thing bad ecm. So that is the rout I am taking. Thank you for your help all.

The CAS recieves its power from the MPI relay, as I said earlier, not the ECU. I forgot to check pins 1 and 2 on the RWD today to see what they have for voltage though. The manual shows a 5v source on both of them, but with all of the circuitry that is not shown in complete detail I can't guess what it should be. Maybe someone that keeps their car with them can check it for us.

Also, swapping the DMM leads won't show power vs no power, it simply changes the polarity, so I'm not sure I understand your post. Either way, it's the CAS or the ECU most likely, so you might as well start swapping parts. First I would use the pinouts I posted above to ring out the harness to be sure that there are no opens, shorts to adjacent pins, or shorts to ground, so you don't blow up any new parts you swap in.

Ok I will try that. The guy who I bought the car from said it ran until he heard a nose in the tranny so he parked it. It sat for 9 months until I picked it up. I know that the ecms are a big problem in these cars. Here is another thing the check engine light does not come on at all. The wires leading to it are as well as the bulb. The boost gauge dosen't move to zero either. From what I was told by motoguy's garage that this too is a common problem with ecm's.

Those arent' necessarily common problems, they're just a good indicator that the ECU is bad. The common cause is the leaking caps. The bullshit that leaks out eats up the board. ISC drivers go from time to time as well, but overall, these things are pretty robust.

So those symptoms point to the ECU being the first thing you will want to swap out. You can also open it up and look for bad caps to be sure before spending the money.

Well like a I might sound like a broken record the ECU IS BAD! I bought one for 50 bucks plugged it and whamo the fucking car started. I must have missed something or maybe I was Right! But thanks anyways.