DTC P1125: Accelerator Pedal Position Sensors Out Of Range Or Disagree: Description

WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Sierra, 2002 GMC Savana Special, 2002 GMC Savana Camper Special, and 2002 GMC Savana. However, it is still accessible from the selected car via links, so may be relevant.

The Accelerator Pedal Position (APP) sensor is mounted on the accelerator pedal assembly. The sensor is actually 3 individual APP sensors within 1 housing. Three separate signal circuits are used in order to connect the accelerator pedal sensor assembly, and the Throttle Actuator Control (TAC) module:

A 5-volt reference circuit.
A low reference circuit.
A signal circuit.

If only 1 APP sensor DTC is set, the redundant APP systems allow the TAC system to continue operating normally. This DTC sets if the Powertrain Control Module (PCM) detects a condition with more than 1 APP sensor. One APP sensor DTC will not cause the Reduced Engine Power message to be displayed. 2 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 1 APP sensor, this DTC will set and the Reduced Engine Power message is displayed.