Pedal (Throttle) Position Sensor malfunctions

[BigRedWeather]

My Pedal Position Sensor PPS, that is attached to the foot throttle assembly, works for 3-4 months then needs to be replaced. I have to replace it when the truck jerks alot, like it gives it fuel, then stops, then starts giving it fuel again. The fact that it wears a PPS out in 4 months makes me think something is wrong.

Another thing that makes me think something is wrong is that when I go to replace the PPS I can put another one on, and it won't work at all. I'll get under there and fiddle with the wires and finally the PPS will work again. When it doesn't work, the truck will idle, but it won't accelerate when I press the pedal. (The pedal assembly is engaging the PPS properly.)

So I got another Pedal assembly and soldered the 5 wires back into the harness so the wires going to the PPS and the idle switch are new. But I still cannot accelerate when I push the pedal. I have pulled the dashboard and see no damage to the wiring harness.

I would love to re-run the wires from the PPS to the computer If I knew that would fix this. There could be a problem between the computer and the engine, but I don't think so, because the PPS stops working when I try to replace the PPS and I am doing nothing to the computer.

I'm kind of stumped on how to get my truck back on the road when the truck in 99.9999% complete.


Help would be appreciated,


BigRedWeather

 

[BJS]

Sounds like you've replaced the obvious, have you tried checking resistance across the PPS to see if there are any jumps as you move the pedal?

For random problems that seem to fix themselves with you fiddling with stuff I find it best to monitor the sensors in question and attempt to recreate the problem. Good OBDII software on a laptop will usually let you do this.

 

[94f450sd]

There is also a throttle on/off switch on the pedal.check it.if its telling the pcm that youre off throttle it will do what you described