My Dad has a 96 2500 that he is having some problems with. The truck was recently parked for 2 weeks while he was away on vacation. When he got back it was really cold outside (Wisconsin) and the truck did not want to start so he ended up jumping it. He got it going by doing this. Anyways now the Speedo, Tach, SRS, Heating Grid for Engine Starting, Cruise Control and OD are gone. He took it in to one of the local dealers and they said that it needs a PCM or so they think since they didn't sound 100% positive that this would fix the problem. They told him to figure around $700 for the PCM job but that part is non returnable if that was not the problem in the first place. The tech was some kid that was reading out of a book while trying to diagnose it and my Dad thought the kid was not very compotent. Another dealer in the area says that they think it is the Body Control Module but I've been told that there isn't one in this truck. Both of these are Dodge dealers also. My Dad doesn't want to just start throwing parts at the truck since that could really add up in a hurry. He has spent a good chunk of money on this truck already rebuilding the entire front end and replacing all the brakes plus some body work. He loves this truck and it is in perfect condition. He is just frustrated that it gave him trouble after being parked for 2 weeks and not while he was driving it. Without the heating grid working in our weather this truck has remained parked since coming back from the dealer 2 weeks ago. Anyone have any ideas what is going on? Any help would be appreciated so I can get him back on the road again.
Thanks- Pete

 

The first thing I would do is check all the fuses. If they are all good, then pull the connection on the pcm. Clean it out real good then put some di-electric grease on it. Plug it back in and if it works then you know that was the problem. If it still doesnt work, check for wires that have been chewed on or through by mice or other animals. Someone else might have some more ideas on what to check. Good luck

 

It definetly sounds like a PCM problem, all those things are controlled by it.

The best you can do , is as suggested above , then after that , get an FSM (it will prove more than worth the $$) and check the pinout on the ecm , see if there is power where/when there should be. Use ONLY a volt meter for this , a test light could draw enough amperage to fry the psm if it isn't already. And i think 700 bucks is a tad steep for an ECM. We got one for our 96 v10 at work for 400 or so CAN.

You can change out a PCM in a matter of minutes , so don't let them charge you for it.

You could also (for a quick check) unplug the ESS , and check to see if there is 5V going to it with the key on, if there is , at least the PCM is being powered up , which i suspect it is not. If you find there to be no power , then the ecm is probably not being powered up , or it is indeed fried , which i highly doubt.

Do 96's have OBD II? i know my 95 does not, If it does , see if a DRB or OBD scanner can even connect to the PCM (with the key on), if it can't the ecm is likely not being powered, this could be a fuse , or a broken wire (mice?)

 

see this post (regarding the jump starting in first couple of posts)

https://www.dieseltruckresource.com/...ad.php?t=86461

And see this post Last page:

https://www.dieseltruckresource.com/...ad.php?t=73036

 

If the positive and negative jumpers were crossed during a jump start the PCM could have fried.

"It needs a new PCM", is a very common dealer misdiagnosis, most dealer "mechanics" are lost if the computer doesn't tell them what is wrong so jump to the expensive conclusion that the PCM is bad. The only real way to tell if the PCM is bad is to swap with donor vehicle or buy a new one. Used PCMs are very hard to come by.

The PCM is a hardy unit that rarely fails, I would look closely at the engine speed sensor wiring or just replace the ESS before messing with the PCM.
Be careful when probing with a voltmeter that you don't enlarge any female connectors, this is a very common problem.