Does anyone have the pinout for a e99 7.3 GEM? I cannot find it anywhere, narrowed 4x4 problem down to clutch position switch at the gem but I do not know what wire it is. There is nothing wrong with the switch itself because the truck starts fine when it is depressed. Thanks for any help.

 

For a what???

 

1999 ford f250 7.3 Generic electronic module (GEM)


Truck will not shift into 4low unless I ground the brown white wire on the solenoid. I have hooked up the autoenginuity and I get no indication from the clutch switch during checkout. The switch works though because the truck starts fine. I am hoping a wire that goes into the GEM is bad?

 

Electronic or manual shift on the fly?

The CPP switch is a 3-pole, single throw switch. Only one set of the poles is used for the starter circuit. So while starter engagement does indicate the switch is being actuated, it doesn't indicate that the other two sets of contacts are functional. According to the schematics for the 99 SD, a second set of contacts goes to the PCM as an input signal, the third set shows in the diagrams as unused.

The factory schematics don't show there is a CPP input to the GEM, but the diagnostic procedure indicates that there should be one on pin 1 of C240c (RED/WHITE WIRE) which is the neutral sense input for an auto transmission-equipped truck. Since the schematics are silent on how the CPP signal gets there, I don't have any idea. Check for a ground on that pin when the clutch pedal is pressed and "high" voltage when the pedal is released.

 

Thanks, its for ESOF btw.. I just wanted to ensure everything else checks out before I swap the most expensive part (GEM).. 4low is the only issue I have, nothing else in the truck malfunctions, which seems to be unusual from what I read on here. I took the clutch switch apart and it seems to work fine.