Code P2128 and P2138

jancebc · April 2

I have a 2015 Silverado with the 5.3, it is my first truck so thats why I am coming here to look for help. Truck goes into limp mode when slowing down and off of the gas. I have replaced the actual peddle assembly itself after recieving the code P2128, but after replacing it now goes to P2138. Just looking for any insight anyone may have to this problem. Thanks!

newdude · April 2

Did you buy a new OEM pedal? Or aftermarket?

rav3 · April 2

p2138 chevy silverado

Code P2138 on a Chevy Silverado indicates a voltage mismatch between the two internal sensors of the accelerator pedal (APP), causing a "Reduced Engine Power" warning and sluggish acceleration. It is often caused by water leaking from the A-pillar/roof causing corrosion in the harness, or a failed pedal assembly.

This video explains the causes of the P2138 code and how to fix it:

Related video thumbnail

03:47

HVAC Mechanic

YouTube• Dec 2, 2023

Common Causes & Fixes

Water Intrusion (Most Common): Water leaks from the roof/antenna, damaging the body harness connector. The fix is to fix the leak and clean the harness connector with electrical cleaner and apply dielectric grease.

Accelerator Pedal Position (APP) Sensor: The pedal assembly itself fails, requiring replacement (GM P/N 25830023 is common).

Aftermarket Equipment: Pedal Commanders or other devices hooked into the system can throw this code.

Wiring Issues: Inspect the harness for the pedal for frayed or broken wires.

Symptoms

Check Engine Light illuminates.

"Reduced Engine Power" or "Reduced Power" warning on the dash.

Weak or sluggish acceleration.

Intermittent issues that may go away, then return.

Troubleshooting Steps

Check for Moisture: Check the passenger/driver side floorboards and under the dash for wetness (suggests a leak, perhaps from a sunroof or roof marker lights).

Clean Connector: Inspect the pedal connector for corrosion, clean with electrical cleaner.

Clear Codes & Reset: Clear the codes using a scanner. If you don't have one, disconnect the battery, touch the terminals together, and then try a pedal relearn.

Replace Pedal: If issues persist, replace the accelerator pedal assembly.