I have a 2008 2500hd with 6.0L.
Check engine light is on and has been for a week. Read the code and it’s P0604 Internal Control Module Random Access Memory (RAM) Error.
No symptoms at all. No other codes. Have any of you guys seen that?

 

clear it and see if it comes back. Hopefully it's a glitch

 

I did clear it, It did come back immediately.

 

diagnostic for this dtc is to reprogram the pcm. if the code resets replace the pcm.

 

Are the places that provide plug and play PCM's (Like Flagship one) with the VIN a reasonable option. or do they require further programming that has to be done by a dealer?

 

Services like flagship one can be reliable but you’ll need to follow their installation instructions exactly in order to prevent warranty problems. You’ll also need the VIN and part #’s off the existing PCM when you contact them.

FYI control modules for many vehicles are getting hard to find, so you may need to plan to send your PCM in for repair as opposed to replacing it.

Before you look at that, however, I’d advise you to verify all the power and ground feeds for the PCM are good as well as check for pin fitment issues at the connectors. The PCM can’t function properly if there’s a power/ground supply problem.