GM Service Manual Online
For 1990-2009 cars only

DTC Descriptor

DTC C0297 00: Brake Applied Output Circuit

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

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 for setting the DTC is no longer present.
    • The history DTC clears after 40 fault-free ignition cycles.
    • The DTC can be cleared using a scan tool.

Reference Information

Schematic Reference

    •  Antilock Brake System Schematics .
    •  Body Control System 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 .

Scan Tool Reference

Control Module References .

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 TCM and the harness connector at the ECM.
  2. Connect a test lamp between the signal circuit terminal of the TCM and a known ground.
  3. Ignition ON, press and release the brake pedal. The test lamp should illuminate ON and OFF when depressing and releasing the brake pedal.
  4. If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.
    If the test lamp does not illuminate test the signal circuit for open/high resistance. If the circuit tests normal, replace the BCM.
  5. Ignition OFF, connect the harness connector at the TCM.
  6. Connect a test lamp between the signal circuit terminal of the ECM and a known ground.
  7. Ignition ON, depress and release the brake pedal. The test lamp should illuminate ON and OFF when depressing and releasing the brake pedal.
  8. If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, replace the TCM.
    If the test lamp does not illuminate test the signal circuit for open/high resistance. If the circuit tests normal, replace the TCM.
  9. If all circuits test normal, replace the ECM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References