Can someone help me with PCM wiring problem?
I have a 98 Chevy C1500 4.3L Engine. The wiring from the TPS to the PCM is showing low voltage. I checked the black and the gray, they have normal voltage but the dark blue one that goes from the TPS to the PCM is reading .02. Does this mean that the PCM is no longer working or is there a relay or sensor that can be replaced to repair the voltage? I've had it diagnosed at my local auto store and the code that it sending out is P0122. Please help.
- mcLv 49 years agoFavorite Answer
The blue wire is the 5.0 volt reference signal from the vcm. (Vehicle Control Module) The blue wire sends a signal to tps sensor. If the voltage is low check for bad connections at the vcm and tps(throttle position sensor), if no problem is found with wiring, I think the vcm is bad.