Well, looks like I'm in for a new PCM.

Cleaned the connectors, changed the battery (fully charged), truck runs fine but dies in 3 to 5 miles. After an hour or so it'll start right up again.

Tried the ice trick, cut the waiting time down to 20 minutes.

to Indy for calling it.

 

So, since I will be replacing the PCM I have a dumb question.

Has anyone figured out a way to cool these things to keep this from happening, or am I just going to have to replace it every year or so?

Maybe put 2 small 12V axial fans at the bottom keyed to the ignition?

 

Vent some air to it with a CAI setup.

No problem on the kudos my friend. Just happy to help. 99s have a couple of gotchas and that just happens to be one of them.

IndyDurango

 

I was thinking, how hard is it to move the PCM? I guess I never noticed it before, but it seems abnormally hot under the hood after the truck's been running a while (although all temps and pressures show normal on the dash).

 

UPDATE:

Well, ordered a new PCM, hopefully should have it by the end of the week. Pulled the old one out, turned the ignition on, got the same "NoBus" error code. Hopefully I'm on the right track.

 

moving it out from under the hood would require extending all the wires that run to it, not really worth it, the overheating issue seems to be magnified on dark colored trucks, the heat build up from the sun on the fenders has something to do with this im sure, maybe put some spacers between the fender and the PCM to slow some of the heat transfer from the fender to the PCM

 

Interesting that you should mention this, the 'Rango is Dark Patriot Blue. I've already located a few spacers in the garage to push the new PCM out about a half inch off the mount plate.

It just seems strange to me that this issue cropped up as "out of the blue" as it did, and needless to say I'm trying to figure out a way to keep it from happening again. This is my wifes DD, she's usually got the kids and grandkids in it. I hate the thought of getting them stranded.

 

UPDATE III:

Well, got the new PCM, got it cleaned and installed. Truck fired right up and seemed to run OK. The truck hadn't gone more than about 5 miles or so since this problem began (without dying) I put 11 miles on it as a test run and it still made it home. So, it looks like this was at least part of the problem.

Issue now is, the "brake" and "ABS" lights are on. No CEL, no codes but the lights are on steady. Is this being caused by something in the new PCM?