communication erros

I've got a 94 Int. w/180k+ miles on it. All in all it's been a good car. But now fairly regularly it has no communitcation with the compter when you start it. When I say none you have no tach, no gear indicator, basically no dash readings and it's stuck in limp mode. It used to happen sparatically going down the road. You used to be able to stop, turn it off, restart and it would be OK, sometimes. Now it's just stuck. I don't remember the code numbers but it's basically saying the trans and the car computer aren't talking.

I've unplugged the main harness from the computer, blew some compressed air across it to blow the dirt out, put some dielectric grease on it and put it back together. For a while it worked fine, then it started "limping" again.

Any idea's where to start. I'm sure it's not as simple as replacing the computer. I'm guessing something's loose/broken/shorted.

By your left front shock tower, there are two big electrical connectors, they connect the TCM to the PCM. My suggestion, take off those connectors and do the same thing you did when checking the modules; clean off the terminals and make sure you don't have any built up crap in there.

I'll give that a look this evening and see what happens. It's actually my dad's car he let me so graciously borrow. I'd like to drive it back to him instead of tow it back.

OK, removed the negative battery cable, then went to the passenger side strut and unplugged all 4 of those big connection. I blew air across them, then put dielectric grease on the contacts. Plugged everything back in, hooked the battery back up and it worked fine. I got in it this morning, same problem. No dash activity. Next idea? Or did I unplug the wrong connections.

I've got a 94 Int. w/180k+ miles on it. All in all it's been a good car. But now fairly regularly it has no communitcation with the compter when you start it. When I say none you have no tach, no gear indicator, basically no dash readings and it's stuck in limp mode. It used to happen sparatically going down the road. You used to be able to stop, turn it off, restart and it would be OK, sometimes. Now it's just stuck. I don't remember the code numbers but it's basically saying the trans and the car computer aren't talking.

I've unplugged the main harness from the computer, blew some compressed air across it to blow the dirt out, put some dielectric grease on it and put it back together. For a while it worked fine, then it started "limping" again.

Any idea's where to start. I'm sure it's not as simple as replacing the computer. I'm guessing something's loose/broken/shorted.

We own a 96 Dodge Intrepid w/ 188,000 miles on it. Around 150,000, the vehicle began exhibiting the same behavior as the 94 listed above; no dash activity and the transmission stuck in limp in mode (limp in mode = transmission operates only in park, 2nd gear and reverse).

After much perusal of the Dodge manual wiring schematics, the problem appeared to be in three places:

1. The electrical part of the ignition switch pin 4
2. The wire between the ignition switch pin 4 and fuse 17
3. Fuse 17 on left side of dash

Unless you have an event that would obviously break a wire, wires don't break - the connections on a wire do. Therefore, number 2 above was ruled out until numbers 1 and 3 were checked.

To check number 3 above, the fuse was removed, checked, and reseated. This did not fix the problem.

The problem turned out to be number 1 above, the ignition switch. Note, this is not the key portion of the switch but the plastic electrical switch that sits behind the key tumbler. The part cost under $30 US from AutoZone and with the correct E-4 and E-6 socket (the female version of a Torx), took about 30 minutes to replace.

Since my curiousity would not allow me to simply replace the part and be happy with the dash and transmission working again, the switch was disassembled. There are 6-8 electrical contacts inside of which 2 sets (4 contacts) were very burned and pitted. It's a wonder that the dash and transmission computers ever turned on. This process took over 30,000 miles to troubleshoot; however, the car has worked flawlessly since and has been a true blessing to us.

God bless you in your adventures,
Dave

replace your ignition switch very comon at that mileage

Well, I got the old one out and went to AutoZone to get a new one. It wouldn't line up quite right and when I looked at it the mounting ears they were not offset like the factory ones were. I tried to put it anyway. With the car running as soon as you touch the key the car shuts off, not good. It was bad enough that bumping it with you knee or a heavy set of keys could shut the car down. So to Advance Auto Parts we go. I ordered one, should be here today hopefully have it fixed this evening. Thanks for all you help ya'll. On a good note though it is essentially in a theft proof mode right now with most of the sterring column components disconnected :p

you know at the dealer they are not too pricey and you generaly get the right part for your car and may be better quality just a thought thou especially
for this type of problem i normaly preffer dealer then i know the part is made for my car but just personal preference but good luck anyway

Well, I put it in this evening and so far so good. I'll keep you posted if anything happens otherwise. I do truly appreciate all the help, I would have never guessed that one.