I've been trying to solve a no-start problem with my '01 1500 4x4, and I think I may have finally narrowed it down a bad PCM. I've had another thread going about it so far (it can be viewed here: https://dodgeforum.com/forum/2nd-gen...fuel-pump.html), but I thought I'd start a new one since that thread started with me looking at other possible causes, and things seem to be going in a different direction now. Hopefully this separate thread will make searching for PCM threads easier for other people in the future.

Anyway, I have read/been told conflicting things about the steps required to install a new PCM. Some folks say that matching VINs and odometer readings are required, while others say that as long as the replacement PCM has a (read: "any") VIN and odometer reading programmed, only the vehicle specs need to match (engine size, transmission, 4x2 or 4x4, etc.). Can anyone clear this up for me?

Can I simply purchase a junkyard PCM (if I can find one) and slap it in with no programming to see if that makes the truck run? Or do I need to purchase a new/replacement PCM? If that is the case, can I purchase a remanufactured one? I see that O'Reilly's sells Cardone remanufactured PCMs that can supposedly be pre-programmed with the VIN and odometer reading if provided by the customer at the time of purchase.

I called my dealer and asked, and they said they can program a PCM for $100, but it has to be installed in the vehicle (meaning I'd have to have the truck towed to them), and I was told by the service manager that sometimes programming used PCMs "doesn't work." Is that just the dealer's way of steering people away from aftermarket/remanufactured parts? Or do I really just need to purchase a dealer/OEM computer? (really don't want to go that route because of the high cost, but will do so if that's the only likely solution)

Thanks in advance for any help!

 

I replaced one on an 04, different PCM but probably similar process. I needed to match the part number on the front of it. I bought a used one from ebay, the first one would kick the truck over but wouldn't hold low idle, it'd just die. Seller immediately sent me a second one, and the second one worked just fine. However to get it inspected (emissions), I needed to have the dealer program the VIN into the new (used) unit.

Mechanic said he was surprised that I drove a used one in, he said usually they need to be programmed before they're run. They are used to charging to install and program the pcm. Dealer didn't have new ones available, they sold re-manufactured ones - which I don't know what the re-manufacturing process is, would they do than clean up the case?

Here is the thread from the 3rd gen, if it helps... There is a reference to a company that will sell you a replacement AND program it for you, so you can just drop it right in.

https://dodgeforum.com/forum/3rd-gen...acement-2.html

Good luck, let us know what happens !

 

On the 01, you need to have the vin programmed into the PCM. Most shops should be able to do this. Cluster remembers the mileage.

 

Hi - I have had some experience with a PCM in the past and am now facing another PCM issue.

I bought a used 2005 Dodge SX 2.0 (base model) and the guy I bought it off of provided an additional PCM aside from the "original" - he did an engine swap and was having battery recharging issues. I know that the voltage regulator is part of the PCM's internal workings - but when I swap out the PCM do I have to reprogram the VIN etc.?

I owned a 2005 Dodge SX Sport in the past and a packrat chewed my injector wires and it knocked out the circuit in the PCM - I did a search of all the auto wreckers in North America - found one for cheap (Dodge dealer wanted $2000 for a new on at the time + labour + towing) I found a PCM from and Auto Wreckers in Texas - he sent it within a couple of days and I installed it - crossed my fingers when starting and it work great - no problems at all.

So is this a matter of hit and miss - can I take just the PCM in to get it reprogrammed - or does it have to be in the vehicle?

As it is a sensitive piece of equipment I don't want to "fry" anything or have my car lock up on me..

Any help will be much appreciated!

Thanks

 

HeyYou,
Any chance you can offer some input on my PCM situation?
Have a 2002 2500 with the 5.9 V8 (which we'll call truck #1) that died. After all other diagnostics were run, we concluded that the PCM was fried. We also tried swapping suspect PCM from Truck #1 into a 2001 also with the 5.9 V8 (Truck #2) and it didn't start start this truck, either.

Then, we put a known working PCM from another 2001 (again, also with the 5.9 V8) (Truck #3) into Truck #1 and drove it down the road for about a mile before Truck #1 died again and wouldn't restart. To see if we inadvertently fried the PCM from Truck #3, we put Truck #3's PCM into Truck #2 and it started right up. Unfortunately, truck #3 is no longer around to see if Truck #3 PCM would still work with truck #3. However, since it started truck #2, I'm guessing it would.

I haven't tried truck #2 PCM in truck #1, since I'm honestly a little afraid truck #1 is destroying PCMs and I don't have any more spares laying around.

Based on what happened to Truck #1 with Truck #3's PCM (died a mile down the road), does that sound like it could simply be an issue of not having the right VIN programmed into the the PCM/ security issue?

Thanks for any input you can offer.

 

It could be. Since it started it and let it run. Try it with truck #2 and see if it does the same thing.

 

Generally, if there is a VIN mismatch, airbag, and abs lights will be on, and those systems will be disabled. Aside from that, shouldn't be any other consequences. I would more suspect that truck #1 has more than one problem......

 

I ended up purchasing a replacement PCM from allcomputerresources.com. I provided my VIN at the time of purchase, and the unit came pre-programmed for my vehicle.

I had a similar issue though, and at first the truck would not start with the replacement PCM. The shop working on it finally realized that the crankshaft position sensor had gotten fried by the previous PCM, and once they replaced that, the truck started right up. It's still running today. I have never figured out what caused the intial issue (presumably the original PCM took a dump and took out the crankshaft sensor with it, but I'm not sure what killed the PCM), but I'm suspicious of a weak ground somewhere. I remember smelling what I can only describe as melting wires a day or two before the truck died, so I feel certain that there was an electrical problem somewhere...I've just never been able to locate it.

I hope this is helpful. Best of luck!!!