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DTC P1125 — LNP or LNQ

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P1125 00: Accelerator Pedal Position (APP) System

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

APP 1 Sensor 5V Reference

P0641 00

P2122 00

-

-

APP 2 Sensor 5V Reference

P0651 00

P2127 00

-

-

APP 1 Sensor Signal

P2122 00

P2122 00

-

-

APP 2 Sensor Signal

P2127 00

P2128 00

P2128 00

-

APP 1 Sensor Ground

-

P2123 00

P2123 00

-

APP 2 Sensor Ground

-

P2128 00

-

-

Typical Scan Tool Data

APP Sensor

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: The engine is operating at idle

Parameter Normal Range: APP Sensor 1 0,9-1,2 V

Parameter Normal Range: APP Sensor 2 varies 0,45-0,62 V

5V Reference 1

0 V

0 V

APP 1 2,08 V

5V Reference 2

0 V

0 V

APP 2 0,86 V

APP Sensor 1 Signal

0 V

0 V

5 V

APP Sensor 2 Signal

0 V

0 V

5 V

APP Sensor 1 Low Reference

-

5 V

-

APP Sensor 2 Low Reference

-

5 V

-

Circuit/System Description

The accelerator pedal assembly contains two accelerator pedal position (APP) sensors. The APP sensors are mounted in the pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to the position of the accelerator pedal. The engine control module (ECM) supplies a separate 5 V reference and low reference circuit for each of the APP sensors.

The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1 V at rest to above 4 V when fully depressed. The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 V at rest to more than 2 V with the accelerator pedal fully depressed.

Conditions for Running the DTC

    • DTCs P0641 00, P0651 00, or P0697 00 are not set.
    • The ignition is ON or the engine is operating.
    • The DTCs run continuously once the above conditions are met.

Conditions for Setting the DTC

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

Action Taken When the DTC Sets

DTC P1125 00 is a Type B DTC.

Conditions for Clearing the DTC

DTC P1125 00 is a Type B DTC.

Diagnostic Aids

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

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Note: If DTCs P0641 00, P0651 00, and P0697 00 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:

    • Damaged components
    • Loose or improper installation

Circuit/System Testing

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

  1. With the ignition ON, test for 4.8-5.2 V between the applicable B107 Accelerator Pedal Position Sensor 5 V reference circuit and ground.
  2. If less than 4.8 V, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
    If greater than 5.2 V, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
  3. Using a DMM, measure the voltage between the 5 V reference circuit and a low reference circuit.
  4. If less than 4.8 V, test the low reference circuit for an open circuit.
  5. Install a 3 A fused bridging wire between the applicable signal circuit and the applicable 5 V reference circuit for APP sensor 1 and 2. Verify that the scan tool accelerator position (APP) sensor parameter is greater than 5 V.
  6. If less than 4.8 V, test the applicable signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
    If more than 5.2 V, replace the B107 Accelerator Pedal Position Sensor.
  7. Install a 3 A fused bridging wire between the applicable signal circuit and the applicable 5 V reference circuit for APP sensor 1. Verify that the DMM volt meter scan tool accelerator position (APP) sensor parameter is greater than 5 V.
  8. If less than 4.8 V, test the applicable signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
    If more than 5.2 V, replace the B107 Accelerator Pedal Position Sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Repair Verification

    •  Accelerator Pedal Position Sensor Replacement
    • Control Module References for ECM replacement, setup, and programming
   


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