GM Service Manual Online
For 1990-2009 cars only

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 C0297 00: Brake Applied Output Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Brake Signal

C0297 00

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Circuit/System Description

The body control module (BCM) provides a 5-volt reference voltage and a low reference signal to the brake pedal position sensor (BPPS). When the brake pedal is applied, the BPPS sends a variable voltage signal, that will increase as the brake pedal is applied, through the stop lamp switch signal circuit to the BCM. The BCM then applies a signal through the stop lamp switch signal circuit to the engine control module (ECM) and transmission control module (TCM).

Conditions for Running the DTC

    • The engine must be ON.
    • The brake must be applied.

Conditions for Setting the DTC

The BCM detects a short to ground in the stop lamp switch signal circuit.

Action Taken When the DTC Sets

    • The BCM stores the DTC to memory.
    • The Service Vehicle Soon indicator is commanded ON.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

Exterior Lights Schematics

Connector End View Reference

Lighting Systems Connector End Views

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

Ignition ON, press and release the brake pedal. The stop lamps should illuminate then go out.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the control modules for the appropriate engine RPO listed below.
  2. • L26 - PCM C1 and TAC
    • LD8 - ECM C1 and TCM
  3. Connect a test lamp between the appropriate signal circuit terminal listed below and ground.
  4. • L26 - TAC terminal 6
    • LD8 - TCM terminal 42
  5. Engine ON, press and release the brake pedal. The test lamp should turn ON and OFF when pressing and releasing the brake pedal.
  6. If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit test normal, replace the BCM.
    If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the BCM.
  7. Ignition OFF, connect the at the appropriate TAC or TCM control module.
  8. Connect a test lamp between the appropriate signal circuit terminal listed below and ground.
  9. • L26 - PCM terminal 32 C1
    • LD8 - ECM terminal 77 C1
  10. Engine ON, press and release the brake pedal. The test lamp should turn ON and OFF when pressing and releasing the brake pedal.
  11. If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the appropriate TAC or TCM.
  12. If all circuit tests normal, replace the appropriate PCM or ECM control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Brake Pedal Position Sensor Replacement
    •  Control Module References for BCM, PCM, ECM, TCM and TAC replacement, setup and programming