6.4L at the dealer for 4 days. PCM not communicating.

[F350FINALLY]

Took my truck in last week for some warranty work. I have had it exactly one year and it has just under 10k miles. No mods or chips. I had a short list of minor items that I wanted looked at. One was getting flashed to the latest PCM programs.

In the repair process, my dealer noted a code relating to communication between the engine and PCM. This led them to replace the PCM(1 day waiting for part). Upon receiving the new PCM they performed the latest flash and received the same code. Truck has been sitting their as they work with Ford to resolve the problem. Anyone familiar with codes relating to communication between PCM and engine? Any suggestions?

Thanks,

PS The truck was running fine before my visit even with the stored code.

[rlchv70]

The ECU does not need to communicate with the engine. The engine is dumb, and can't communicate with anything. The ECU is its brains.

[Stymie]

if the dealer installs the flash wrong, it can kill the pcm