TPS and Tranny cant get along under load!

[TacosnBeer]

Ok, took her for a drive and she is still acting weird. It's much better than before I got the TPS dialed in however, she is still popping the erratic VSS code. I put a new VSS in and it's still popping the code. Also, my speedo is 10mph fast still. Lastly, under load the speedo goes freaky and pulses back and forth.

I am at a loss! damn... I just can't figure this out.

 

[Pinger]

A story.
Back when Porsche launched the 964 model of the 911 there were instances of the ABS being activated under hard acceleration. After lengthy investigation it was found that the new dual distributor set up was bringing the HT leads into close contact with the ABS wiring under the movement of the engine due to torque reaction and inducing voltages there that activated the ABS.
Movement due to torque reaction under load can find a break or short circuit in a wire - or otherwise come into contact with what it's not so supposed to.. How is the routing on your VSS wire?

 

[TacosnBeer]

A story.
Back when Porsche launched the 964 model of the 911 there were instances of the ABS being activated under hard acceleration. After lengthy investigation it was found that the new dual distributor set up was bringing the HT leads into close contact with the ABS wiring under the movement of the engine due to torque reaction and inducing voltages there that activated the ABS.
Movement due to torque reaction under load can find a break or short circuit in a wire - or otherwise come into contact with what it's not so supposed to.. How is the routing on your VSS wire?

Pinger, interesting you mention the ABS... so, my ABS light comes on occasionally when driving. When I first start it and go, the brakes act weird for the first few times I hit them then they are fine. its been progressively getting worse. Also, recently, the switch was not working till I unplugged and replugged in the wires. Its working now but, could that be the reason for the ABS light and bad info feeding the computer?

All the wires to the VSS are clean and protected. One other thing that popped up last time I drove it was the security light.. it came on and off a few times but didn't affect the driveability at all.

 

[Pinger]

Pinger, interesting you mention the ABS... so, my ABS light comes on occasionally when driving. When I first start it and go, the brakes act weird for the first few times I hit them then they are fine. its been progressively getting worse. Also, recently, the switch was not working till I unplugged and replugged in the wires. Its working now but, could that be the reason for the ABS light and bad info feeding the computer?

VSS and wheel speed sensors at cross purposes and confusing the ABS?
If the dash light is illuminated because of an electrical problem, it tends to stay on (and generate a fault code). If the dash light is illuminated because of the ECU reading a speed mismatch it should only be for the duration of the speed mismatch.

All the wires to the VSS are clean and protected. One other thing that popped up last time I drove it was the security light.. it came on and off a few times but didn't affect the driveability at all.

It was just in case the torque reaction under load was moving it around I mentioned that stuff.

 

[TacosnBeer]

VSS and wheel speed sensors at cross purposes and confusing the ABS?
If the dash light is illuminated because of an electrical problem, it tends to stay on (and generate a fault code). If the dash light is illuminated because of the ECU reading a speed mismatch it should only be for the duration of the speed mismatch.



It was just in case the torque reaction under load was moving it around I mentioned that stuff.

So, now that I have the new VSS, adjusted the TPS properly, what do you think I should tackle next? Brake Switch? I am not sure where to go next. Or, just take a hammer to the computer. LOL - just kidding.

I did get P0281 Brake Switch Retainer Curcuit but, that was when the brake lights weren't working and i juggled the plug and they're on now. I don't understand why I am still getting C0237 Rear Speed Sensor Erratic Code with a new VSS in there though...

 

[Pinger]

VSS is on the gearbox measuring propshaft speed - yes?
Not sure how the ABS sensors are configured on these trucks. Guessing that the VSS serves the rear axle and there are also sensors on the front wheels. If the reluctor rings are exposed, the can corrode and split and throw up spurious readings - which being non electrical don't throw codes (viewed as ABS operation). If you have reluctors like that on the front wheels check for cracks. All this assumes the ECU reads them in conjunction with the VSS. I'd check that stuff just to be sure nothing amiss there. Tyre pressures and sizes also - especially if any have been changed relatively recently.

 

[TacosnBeer]

VSS is on the gearbox measuring propshaft speed - yes?
Not sure how the ABS sensors are configured on these trucks. Guessing that the VSS serves the rear axle and there are also sensors on the front wheels. If the reluctor rings are exposed, the can corrode and split and throw up spurious readings - which being non electrical don't throw codes (viewed as ABS operation). If you have reluctors like that on the front wheels check for cracks. All this assumes the ECU reads them in conjunction with the VSS. I'd check that stuff just to be sure nothing amiss there. Tyre pressures and sizes also - especially if any have been changed relatively recently.

Its a 2wd 4L60E and the VSS is on the pass side of the tranny tail shaft. No, the speedometer is 10mph fast. It was that way with the old VSS and this new one. The front rotors are new so, I am guessing there arent any cracks in the rings. Not sure about the front speed sensors though - don't know if they were replaced with the brakes. When I got the truck all the brakes had been replaced and its always had these problems since I bought it. I have stock size tires on it... 235/70r15 so, no weirdness there.

 

[HotWheelsBurban]

Its a 2wd 4L60E and the VSS is on the pass side of the tranny tail shaft. No, the speedometer is 10mph fast. It was that way with the old VSS and this new one. The front rotors are new so, I am guessing there arent any cracks in the rings. Not sure about the front speed sensors though - don't know if they were replaced with the brakes. When I got the truck all the brakes had been replaced and its always had these problems since I bought it. I have stock size tires on it... 235/70r15 so, no weirdness there.

2wd ABS sensor is a box that's mounted on the backing plate ( between the rotor and the spindle). I have replaced the right side one, and have both of them new to replace once I can park the Burb long enough. I plan to do these with the control arms since everything has to be pulled down for both jobs.

 

[TacosnBeer]

2wd ABS sensor is a box that's mounted on the backing plate ( between the rotor and the spindle). I have replaced the right side one, and have both of them new to replace once I can park the Burb long enough. I plan to do these with the control arms since everything has to be pulled down for both jobs.

Thanks, pretty savvy at where they are... just not sure how they play into my problems or if they could be contributing factor.

 

[letitsnow]

Not sure if 4wd is different as far as where/what the ecm does with the sensor info, but I have cut the wires on my front abs sensors on both my '99 k2500 and '98 s10. This didn't affect the speedometer or shifting on either truck.