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(Fixed) I have a 2015 Ram 1500 4x4, 5.7. The truck was sitting for several months after a wreck repair. I drove the truck several times with no issues and no lights. Upon starting it to take it for my salvage inspection the check engine light was on with a P0600 code. My Autel scan tool is showing readings from all of the modules. My also resistance is 60 ohms. The scope forms don't look too bad but I'm using a low level OTC scope so it's hard to see it. The truck seems to be running fine. Is there a better way to troubleshoot this? I am to the point of ordering a new PCM. Thanks
Last edit: 5 years 3 months ago by jconiber. Reason: Misspelling
jconiber wrote: Upon starting it to take it for my salvage inspection the check engine light was on with a P0600 code. My Autel scan tool is showing readings from all of the modules.
Are you sure it's showing all the modules that are installed on the truck? And have you scanned all modules for codes? Or even the ECM for OE codes. Might be something there pointing to a specific module.
With the vehicles history both collision damage and rodent damage are possibilities which may have taken a module offline. Since you've got 60 ohms at the DLC the bus is intact end to end but that doesn't mean a branch hasn't been cut somewhere or a module is dead.
I am not sure if it's all of the modules or not. The code is instant. Sets even before the truck starts. There have been multiple other communication codes but they were all easily cleared. I haven't located a list of all modules yet. I also unplugged the bus taps at the plug under the dash, so I'm thinking I forced most of the other codes.
I did this overnight at the beginning. Still not 100% on my scope picture. I will have to look more closely at the set up to be sure I'm seeing what I should be.
Someone can correct me if I'm wrong, but I can't see that a network problem would cause this. The SI set condition talks about a communication failure between processors, not separate modules. As in, one IC on the PCM board has an issue with another IC on the same board.
I'd still go with power/ground testing before pulling the trigger on a new PCM.
So, after much deliberation and testing, we decided to replace the PCM. We ordered a reconditioned plug and play unit that was supposed to be ready and shipped in 1 day. It took 3 weeks and wasn't shipped until 3 days after we cancelled the order. (Company refused to cancel because they had already shipped the unit. The program date was 2 days after we cancelled. F'n crooks) Anyway, upon initial install it started the truck fine but gave us about 20 different module codes. We had to do a full code delete and it's been fine since. No codes at all and the truck even seems to be running smoother that before. Thanks for all of the insight on this issue.
Topic Author
The SI set condition talks about a communication failure between processors, not separate modules. As in, one IC on the PCM board has an issue with another IC on the same board.