have an 04.5 truck that won't start, cranks but no start, scan tool says no communication. any ideas? where is the pcm located on these trucks?

 

If it still has the stock lift pump, I would start there.

 

lift pump is in the tank, it will not cycle with key. I tried to bypass with jumper wire and can get the pump to work that way. I know this truck may need a recovery file, but need communication with the pcm first

 

try using an alternative fuel source to try and see if it will start and run. the pcm i believe is on the drivers side on the motor next to the ecm

 

so is the pcm, ecm the same box on the side of the engine?

 

no should be 2 boxes if i rember off my 03

 

I'm pretty sure there is just one module with 2 harnesses that plug into it

 

Check your scan tool connection to the OBDII port. If you bent a pin (pretty hard to do but possible) you might get a com error. If everything at the OBDII looks good you may want to check the backplane and make sure everything is still connected.