[Prince5kids]

I have the PO120 and PO2135 codes, I replaced the throttle bod, pedal assembly, TPS plug and nothing helps. Truck is in limp mode and will barely idle if you press the brake pedal it will try and die, any ideas on what's causing this? Also I cleaned and replaced all ground wires.

 

[RayVoy]

The P0120 is a throttle position sensor (on the throttle body), or the pedal position sensor, on the gas pedal.
The P2135 is from the same area, I think I'd inspect the wiring between the two.

 

[OpalLacod]

The P0120 is a throttle position sensor (on the throttle body)

TPS is built into the throttle body by 2003 on the Silverado. Probably the same for the Sierra. If he did the throttle body, then he swapped the TPS. I don't see any mention of the Pedal Position Sensor in the code definitions I've found for P0120...?

Found this link to be helpful. I used a similar procedure on my separate TPS. Maybe the new TB is bad. Wouldn't be the first time...

Part 1 -P0120 TP Sensor 1 Circuit Malfunction (with Electronic Throttle Body)

Page 1 of 4: P0120 TP Sensor 1 Circuit Malfunction (with Electronic Throttle Body). Symptoms of a BAD TP Sensor 1. What Tools do I Need? Circuit Descriptions of the Electronic Throttle Body Connector.

easyautodiagnostics.com

@Prince5kids I'm assuming the dash is saying "Reduced Engine Power". Did you get the new TB from a junkyard or is it actually new? Have you gone through ALL of your fuses? Did you reset the computer by disconnecting the battery and touching the cables together and/or letting it sit for a while?

 

[Prince5kids]

TPS is built into the throttle body by 2003 on the Silverado. Probably the same for the Sierra. If he did the throttle body, then he swapped the TPS. I don't see any mention of the Pedal Position Sensor in the code definitions I've found for P0120...?

Found this link to be helpful. I used a similar procedure on my separate TPS. Maybe the new TB is bad. Wouldn't be the first time...

Part 1 -P0120 TP Sensor 1 Circuit Malfunction (with Electronic Throttle Body)

Page 1 of 4: P0120 TP Sensor 1 Circuit Malfunction (with Electronic Throttle Body). Symptoms of a BAD TP Sensor 1. What Tools do I Need? Circuit Descriptions of the Electronic Throttle Body Connector.

easyautodiagnostics.com

@Prince5kids I'm assuming the dash is saying "Reduced Engine Power". Did you get the new TB from a junkyard or is it actually new? Have you gone through ALL of your fuses? Did you reset the computer by disconnecting the battery and touching the cables together and/or letting it sit for a while?

Yes the dash says it, I did get a new one, all fuses are good and I disconnected the battery for an hour.

 

[OpalLacod]

The P2135 is from the same area, I think I'd inspect the wiring between the two.

I don't see any mention of the Pedal Position Sensor in the code definitions I've found for P0120...?

Had a brain fart, Ray. Didn't register the rest of the information...

Service bulletin for the next generation of vehicles and their faulty TPS.

https://www.autocodes.com/pdfview.p...ir and Diagnostic Information | AutoCodes.com

Seems relevant. If you cannot find a nicked or broken wire and have traced the wires out (starting with Dark Green), I would verify with a scan tool these 2 internal sensors agree. You said you replaced the plug already, which means it's unlikely you have bent pins in both new components (TB & plug).

 

[Prince5kids]

I checked and the sensors do not agree!

 

[OpalLacod]

I checked and the sensors do not agree!

Check your pins for proper voltages just to make sure it's in the TB. Then warranty the TB. 😬

 

[Prince5kids]

Will try that next, thanks