PCM GPR ground signal not getting to GPR

F350camper

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So i'm working out the bugs on my high mileage Excursion with the 7.3 powerstroke.

I'll try to keep it to the point. The glow plugs are not firing when the key is turned on.

Bottom line is the ground signal from the PCM isnt getting to the GPR. Forscan shows me the EOT is at about 62°F, and the PCM is calling for the glow plugs to light.

So I'm thinking I either have a broken connection from pin 101 of the PCM to the GPR, or the PCM itself is bad.

Next steps are to ohm out the wire from the GPR to the PCM. If I find that to be ok, then I monitor pin 101 right at the PCM while the key is cycled and see if the PCM is bad.

Thought I would throw this out there to those more in the know to see if I'm on the right track.
 
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no mufflers

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yeah if you go through all the wires first you can eliminate one cause and go from there. if all checks out there then it would be a safe bet to change the PCM.
 

F350camper

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ok, Im getting the ground from the PCM all the way to pin 13 of the 42 pin engine harness connector. I lose it someplace between there and the GPR.

Looks like it will be a ***** to mine that wire out. LOL Should be fun.

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F350camper

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WOW, I'm an idiot! LOL. This isn't a CA emissions truck, BUT it is an EXCURSION! So I don't have a GPR, I have a GPC!!! I tell you what tho, that AIHR sure looks like a GPR! :rotflmao:rotflmao
 
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