P1125

DTC P1125

Circuit Description
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, each with the following circuits.
- 5 volts reference circuit
- Low reference circuit
- Signal circuit

The engine control module (ECM) supplies 5 volts to the APP sensor on the 5 volts 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. If the ECM detects two or more APP sensor open, this DTC will set.







Condition for Running the DTC
- The battery voltage is between 10-16 volts.
- The ignition switch is ON.

Condition for Setting the DTC
- Two of three APP sensor signals contain an open circuit.

Action Taken When the DTC Sets
- The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.
- The ECM limits accelerator control range within 40%.
- The ECM inhibits the cruise control.
- The ECM inhibits the PTO control.

Condition for Clearing the DTC
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
If an intermittent condition is suspected, the following may cause an intermittent:
- Poor connections.
- Misrouted harness.
- Rubbed through wire insulation.
- Broken wire inside the insulation.

Check for the following conditions:
- Poor connection at ECM: Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
- Damaged harness: Inspect the wiring harness for damage. If the harness appears to be OK, observe the "DTC P1125" display on the scan tool with the ignition ON and engine OFF while moving connectors and wiring harness related to the sensor. A change in the display will indicate the location of the fault.

NOTE: A disconnected APP sensor may set this DTC.

DTC P1125

Schematic Reference: Engine Controls Schematics