Coming home from a trip with the family, my '07 Aspen starts running high RPMs on the highway, transmission would not shift into higher gears. I stop, do some research and read where the MAP sensor might cause this. I replaced this sensor in front of Auto zone in the rain... much to my surprise the car would not even start after that, engine would turn over but no start. I put the old MAP sensor back on, same thing, would not start. I had the negative battery cable removed during both installs. Had to have it towed 100 miles to my local dealer. They say it is the PCM and will cost $1100. I thinking about fixing it and trading it in. Does all this sound about right? $1100 for the PCM?

 

According to the website factorychryslerparts.com, the PCM itself is about $415. Now with all the programming that the Aspen has I'm pretty sure it's not going to be just plug n' play. Even the key fobs themselves will need to be programmed to the new PCM. So the dealer wanting to charge you $1100 for the PCM plus install and programming really doesn't surprise me.

Dealers can be crooks when it comes to "Programming". Like they really have to do much with plugging up a computer and letting it do all the work. A buddy of mine recently had to pay $150 per parameter change on his Freightliner Truck.

For the most part, the dealer has you by the jewels. Sure you can call around and ask other dealerships or shops, but you will probably get about the same answer. You can go to a junkyard (if you can find one that actually has an Aspen) and pull the PCM from it, but it will still need to be programmed. Again, you will be at their will.

Personally, I'd be asking how the PCM went bad in the first place. Was it damaged by water? I've seen numerous complaints about water leaks on these things. If that's the case, perhaps see if your insurance company might be able to cover some of the cost. Otherwise, I'd be seeing about cutting your losses and trading it in as is.

 

Water damage could be the culprit. The transmission issues started after driving through very heavy rain and the car would not start after leaving the hood up while it was raining. So the gaskets just fail on these to let water in? Also, is it safe to assume my shifting issues were indeed the pcm failing?

 

It is possible it got water on it while driving. Although, due to it's location, I imagine you would of had to travel through some major pooling to splash up to it. Working on it in the rain probably didn't help but even then it shouldn't shorted that easily.

Was it the cause of the shifting issue? Possible. So is low fluid, bad sensors and several other possible culprits. What's sad is even if you do replace the PCM, it may only fix your starting issue. You could still have other issues with the transmission.

Sorry to sound negative, but with today's cars being all computers and sensors, one problem usually leads to another. Each costing more. Hopefully it is just the PCM for you. Sadly, it's an expensive means to find out. Personally, I'd be wanting to see this PCM and know WHY it is failing. Even if that means opening it up to inspect for water damage or other possible reason.

 

Would a bad BCM cause the PCM to fail?
I've had a bad BCM for a while, just wondering before I get a new PCM.

 

From what I just read about the BCM, it can cause other issues within the car. Including but not limited to, failure to not start since the security system runs through it. Can also give false readings on other components such as the PCM. So yeah, it would be my guess to say that it is "possible". However, even though I have messed with electronics practically my whole life, I am no expert when it comes to the computer systems of these vehicles. Really surprised no one else has chimed in here yet. I would definitely ask that question to the service tech who checked your truck.

 

When I say "BCM" I mean the brake control module. I just realized there is a "Body Control Module". I have a bad Brake Control Module and was wondering if that could cause a failure in the PCM...

 

If the brake control module connects in any way to the ECM, it has the potential to cause issues with it. When practically all components within a vehicle connect in one way or another, if one fails it could cause issues with another. Especially when they are sensitive computers. So I can't say the bad BCM caused the issue with the ECM, but it may have as well. Again, probably something you should confirm with the service tech.