mattsauto

2001 Chevrolet Silv. 3500, 8.1L has issues with the APP System. Attached is a screen-shot of the live datastream from my scanner. Where are these APP Sensors located? I found the sensor on the pedal. Is it calling the TPS one of these sensors?
When the truck was running normal, all sensors "Agreed". Now you see that the 2 sensors "Disagree" and the one "Agree". How can I tell which one is bad?

Also attached is a screen shot of the codes as they were set at the time of the Live datastream.

Thanks in advance for your help,
Matt P.

MDTAHOE

I will assume you have a cable less throttle body so the TPS is part of the throttle body and can not be serviced separately. There are 3 common cause for this problem. #1 clean the throttle body. # 2 wiggle the harness going into the t-body while monitoring the data. The yellow wire breaks inside the jacket (you can not see the break unless you strip the wire. If wiggling the causes the data to read disagree then repair the wire. Sometime you must splice in a new connector for the t-body. If none of those fix the issue replace the throttle body.

mattsauto

Thanks MDTAHOE for your quick response. Reduced power mode resets when the ignition is switched off. I cleaned the TB with CRC Throttle body cleaner till it shined. I removed the servo motor and re-greased the gears. They had residue of white lithium but other than that were dry. I removed the TPS and inspected for trash, etc. and found none. I drove this truck for 30 min straight with no issues. When I got it back to the owners house and he jumped in to drive me home, we didn't make it down the street before Red. Pwr mode kicked on. Prior to my cleaning, he couldn't drive 5 miles without Red. pwr coming on. I'll play with the wires and see what happens.
Rock auto shows a listing for a TPS for this truck. Here's the link: http://www.rockauto.com/catalog/rafr...&parttype=5136
Is this sensor not a valid replacement part?

MDTAHOE

That is for a truck that has throttle cables.

mattsauto

just got in from spending an hour with this truck. I've wiggled the wires, the only yellow wire I found was connected to the actuator/servo motor, no change in status. I wiggled the wires to the TPS, no change either. Was 2001 the first year for the fly-by-wire system?