The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of three individual sensors within one housing. The APP sensor 1, APP sensor 2, and APP sensor 3 are potentiometer type sensors. The engine control module (ECM) supplies 5 volts to the APP sensor on the 5-volt reference circuits. The ECM also provides a ground on the low reference circuits. The APP sensor provides a signal to the ECM on the APP sensor signal circuits, which is relative to the position changes of the accelerator pedal angle. The APP sensor 1 signal voltage is low at rest and increases as the pedal is depressed. The APP sensor 2 signal voltage is high at rest and decreases as the pedal is depressed. The APP sensor 3 signal is high at rest and decreases as the pedal is depressed.

DTCs P0642, P0643, P0652, P0653, P0698 and P0699 are not set.

One or more of the APP sensor signals contain an open or short circuit.

DTC P1125 is a Type B DTC.

DTC P1125 is a Type B DTC.

Inspect for any recent engine mechanical repairs. An incorrectly installed APP sensor will cause this DTC to set.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Important:  If DTCs P0642, P0643, P0652, P0653, P0698 and P0699 are set, test and repair those DTCs first.

Verify the integrity of the accelerator pedal, accelerator pedal position (APP) sensor by inspecting for the following conditions:

Important: You must perform Circuit/System Verification before proceeding with Circuit/System Testing.

1. With the ignition ON, test for 4.8-5.2 volts between the applicable APP sensor 5-volt reference circuit and ground.

⇒	If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module.

⇒	If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.

2. Using a DMM, measure the voltage between the 5-volt reference circuit and a low reference circuit.

⇒	If less than 4.8 volts, test the low reference circuit for an open circuit.

3. Install a 3-amp fused jumper wire between the applicable signal circuit and the applicable 5-volt reference circuit for APP sensor 2 and 3. Verify that the scan tool accelerator position (APP) sensor parameter is greater than 5 volts.

⇒	If less than 4.8 volts, test the applicable signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module.

⇒	If more than 5.2 volts, replace the accelerator pedal assembly.

4. Install a 3-amp fused jumper wire between the applicable signal circuit and the applicable 5-volt reference circuit for APP sensor 1. Verify that the DMM volt meter scan tool accelerator position (APP) sensor parameter is greater than 5 volts.

⇒	If less than 4.8 volts, test the applicable signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module.

⇒	If more than 5.2 volts, replace the accelerator pedal assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.