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 Descriptors

DTC C0297 00 : Brake Applied Output Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Stop Lamp Switch Signal

C0297 00

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--

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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 to the ECM and TCM.

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, observe the scan tool Brake Applied Output Signal parameter. The reading should be On, with the brakes applied.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the TCM and the (C1) harness connector at the ECM.
  2. Connect a test lamp between the signal circuit terminal 42 of the TCM and ground.
  3. Engine ON, press and release the brake pedal. The test lamp should turn ON and OFF when pressing 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 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.
  5. Ignition OFF, connect the harness connector at the TCM.
  6. Connect a test lamp between the appropriate signal circuit terminal of the ECM and ground.
  7. • With LS4 -- terminal 7
    • With LZE, LZ4, or LZ8 -- terminal 9
  8. Engine ON, press and release the brake pedal. The test lamp should turn ON and OFF when pressing and releasing the brake pedal.
  9. If the test lamp is always OFF, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the TCM.
  10. If all circuits test normal, replace the ECM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM, TCM and ECM replacement, setup and programming