We have an issue that has come up on the truck and wonder if anyone has encountered something similar.
It just had the head gaskets done. Cab lifted off etc.
Back together now. Initially ran fine.
Seemed to be ok the first few drives.
Then it had issues. When driven over a bump, it would appear to cut out. The transmission would buck.
We suspected connection issues with the main harnesses that have connections on the driver's side coil spring tower. If you shook the connector it would exhibit electrical issues. The cooling fan would kick in, dash lights would flicker etc.

Now, the PRNDL light goes out, the fan comes on, transmission temp on the HNS tuner reads 0 and the transmission is in limp mode.

We have put the truck back to stock tune, checked all of the main grounds from engine to cab and cab to body. We have disassembled the 3 connecters that we suspected and inspected and cleaned them. Inspection did not indicate any obvious issues.

We have reassembled the connecters. The dash lights are fine, the transmission reads temperature, the fan is not on etc., but if we shift the transmission into gear, we can feel it like it shifted but it won't move - like it is in neutral.

Now if we shake the connectors noted above,we get a light in the dash that flashes, "tow module fault".

It appears to be an electrical issue. Anyone encountered this sort of thing?

Randy

 

MIne has done this since new. I'm desperate to find an answer. I would like to know if you found a solution.

Mine = 2008 F350 dually 75K miles and I have just quit driving it. period.

 

check the pins for the wiring harness for the pcm and see if they are bent or pushed in.

 

Moved to the 6.4L Powerstroke Diesel forum.