Chevrolet P1125: Accelerator Pedal Position System Malfunction

What Does The Chevrolet P1125 Code Mean?

The accelerator pedal position (APP) sensors are mounted on the accelerator pedal/TAC module assembly. There are three individual Accelerator Pedal Position sensors within one housing. Three separate signals, a ground, and reference circuits. If only one APP sensor DTC is set, the redundant APP systems allow the Electronic Throttle Control (ETC) system to continue operating normally. This DTC sets if the PCM detects a problem with more than one APP sensor. One APP sensor DTC will not cause the Reduced Engine Power message to be displayed.

Two APP sensor DTCs for the same sensor also will not cause the Reduced Engine Power message to be displayed. However, if two or more DTCs are set involving more than one APP sensor, this DTC will set and the Reduced Engine Power message is displayed.

What Are The Symptoms Of The Chevrolet P1125 Code?

Illuminated check engine light

What Are The Potential Causes Of The Chevrolet P1125 Code?

Below are some potential causes of this DTC:

• APP sensor connector contaminated with oil or moisture (this condition can cause signal “tracking” between the circuits)
• When the TAC module detects a fault in this system, it may set more than one code (due to redundant tests running constantly)

How Can You Fix The Chevrolet P1125 Code?

Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

Poor terminal connection

Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension.

Damaged harness

Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display may indicate the location of the fault.

Faulty PCM

Inspect the PCM and the engine grounds for clean and secure connections.

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> WORKPRO 582-piece Crimp Terminals, Wire Connectors, Heat Shrink Tube, Electrical Repair Kit
>>> GM Genuine Parts 25832864 Accelerator Pedal with Position Sensor
>>> GM Fuel Injection Throttle Control Actuator Module

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Reference Sources

• 2000 Chevrolet Camaro and Pontiac Firebird Service Manual – Volume 1, page 1073.
• GM, 2013, Service Bullettin – Prior To Any Circuit Testing.
• GM, 2015, Service Bullettin – Special Coverage Adjustment – Reduced Engine Power / Accelerator
  Pedal Position Sensor.