So right after i got done washing my truck i get a code, p0500 and my speedo starts going crazy and the truck shifts way late at like 3500rpms. I have just changed out both speed sensors. One on the diff and one on the tranny. None of them fixed my issue and it driving me nuts because I don't know what else it could be. Anyone have this issue before?

 

P0500 No Vehicle Speed Sens Signal

Verify you are getting voltage back to the sensor. Verify you are getting something back from the sensor at the PCM. Might just be a broken wire.

PCM gets vehicle speed cues from the sensor on the diff.

 

Do you know what wire it is back at the PCM? And I'm gonna check to see what kind of voltage it's getting at the sensor once I get home. And which sensor do you think is at fault? Because due to the shifting issue and no abs lights present I would think its the VSS in the tranny, correct?

 

At the ABS controller, its connector 1, pins 1 (red/violet), and 8 (white/violet.) (not sure where that hides on RWAL trucks.... on 4WAL trucks, it will be obvious. )

PCM gets its clue from the ABS controller, C1, pin 12 (white/orange) and goes to the PCM at C2, pin 27.

A dirty connection would probably do this too.

 

Come to think of it. If the PCM receives it's signal from the Orange / white wire, then I'm thinking my "Accu-speed" from jet probably took a hit. I wired it into the Orange / white wire and the jet module could be throwing bad values.. However if this were to be the case would this cause the late shift (doesn't happen everytime) or would that be something different?

 

Just unplugged the jet speed calibrator and it stopped the erratic speedo in idle. I'll know if that's it once I drive it. Gotta catch the train

 

It don't know how much the ABS controller, and the PCM interact when it comes to the ABS lite...... It's *possible* your "accu-speed" is the problem, but, only one sure way to find out.

 

Well it indeed was the module. Time to get a refund from jet

 

At least its an easy fix.