We have a 1998 dodge grand caravan Le (146000 mi) and are having lots of problems. We recently had a short that was causing the radiator fan module to go out and after replacing that and doing 5 feet of rewiring they found that the PCM was causing it to short out and needed replacing. We replaced the PCM and now we are having acceleration problems and it is having a rough time shifting gears and that is causing the steering columnto vibrate. Also the digital read on how many gas miles to the tank we get went from around 345 to 265. We took it back and they said it was just low on trans fluid, we got it back and it is shifting/ driving worse than ever. THe problems aren't constant, though, they come and go from trip to trip.Is this most likely caused by the replacement PCM not working correctly, or is the trans just coincidentally going out now? By the way, we just had the trans fixed a year and a half ago and none of these problems were happening before the PCM replacement...

 

check for loose or corroded ground wires.the ground wire had to be removed when the trans was rebuilt.this will drive the computer nuts.also did they flash program the computer with the latest files from mopar?it seems that most of the fixes lately are reprograming the computer with updated files.

 

Sounds like the PCM might be a mismatch. Possible they didn't do a relearn process. Was this a dealer repair? Was the PCM new, reman, or from salvage? If it is an intermitent problem that didn't show up till the PCM was replaced I would strongly look at something faulty there. When you say trips, do you mean long drives such as a road trip? Or do you mean one drive session, regardless of time and distance, it acts up and the next it doesn't?
Whatever the case a PCM should be put through a learning process when installed. If not a lot of odd symptoms can happen, But they usually don't have extreme effects as you mention. It all seems a little fishy to me though! I could easily see them doing a bad rewire job and shorting the PCM, but not the PCM to cause a short. Another thing to consider is the PCM and TCM comunicate with each other. If one was shorted the other could be as well. Was this a reputable repair shop? Maybe check BBB to see if there is a trend of complaints. A few complaints for a long time buisness is normal but if there is a bunch and they have been in operation only a few years, that would be a red flag.

 

SPAT- We have been using this Midas for the past 6 years and never had a problem before, so I do not think anything is intentional..... they seem kind of frustrated that it isn't working right, too. The PCM was from the Dealer and cost an arm and a leg and they took it to another shop to do the programmomg/ reflashing. When I said TRIPS I ment just normal driving, like 10 miles at a time, if not less...but it does not happen every time. I would say about 40% of the time. Do you think I should just ask them to reflash it, or make them recheck all their wiring? Maybe I should take it to a transmission place and have them tell me if it is the PCM and then take it back to Midas and say stop looking at everything else... Thank you for your reply!

 

Sounds like a reliable shop then. Be worth enquireing at the origional trans shop if the new PCM might have an issue with the TCM. Not sure if the TCM needs to go through a learning process like the PCM. Though unlikely there is always the chance that the new PCM was just a dud. NEW (Never Ever Worked). Intermitent problems are a real pain to diagnose and finding someone willing to try is even harder. I my self am dealing with an intermitent problem. It started just prior to the trans tering up. I watched the trany guy tear it down. The trans was totally shot. Required a complete overhaul. Been dealing with an intermitent stall ever since. But like I said the stalling actually started prior to the trany problems but real close to that time frame, for what ever thats worth. I do know that dodges have a lot of problems with the speed sensores in the trany so might be worth looking into. Mine had been replaced with the overhaul just for good measure.