04 Super Duty No PCM Communication

[forddieseldoctor]

I got an 04 f-series that was towed in cause it stalled repeatedly and another shop told them it needed a pcm. Truck won't crank sometimes and when it does it cuts out while it's cranking. Nothing that is pcm controlled comes on when the key is turned on. I unplugged the engine connector at the pcm and the fuel pump comes to life. I didn't get much time to look at it yet, but I have unplugged the fan clutch, icp, ebp, and egr valve. I performed a brief wiggle test on the harnesses I could get to easily.

 

Has anyone seen a messed up ficm cause the pcm to shut down?

[Bruce Amacker]

Try unplugging the injector feeds- will it run the buzz test?  Shorted injectors shut the PCM down, I've seen it several times, really freaky, loses scan data, won't start, starts and runs bad, always weird complaints, etc...... 

 

[forddieseldoctor]

Even though I unplugged it when I first looked at it I found the ebp sensor shorted out. I even had a little wisp of smoke come out of the connector when I unplugged it.

[8WA Sman]

I take it the CEL was not illuminated in bulb check.

[forddieseldoctor]

Um... Don't remember. I know the glow plug light came on when I turned the key on.