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

Center High Mounted Stop Lamp (CHMSL) Control

B3445 00

1

1

--

Brake Position Sensor Signal

C0277 06

C0277 06

C0277 07

C0277 09

Stop Lamp Switch Signal

C0297 00

C0297 00

C0297 00

--

Brake Position Sensor 5-Volt Reference

C0890 03

C0890 03

C0890 07

--

Brake Position Sensor Low Reference

--

C0277 06

C0277 07

--

Left Rear Stop/Turn Lamp Supply Voltage

1

1

1

--

Right Rear Stop/Turn Lamp Supply Voltage

1

1

1

--

Center High Mounted Stop Lamp (CHMSL) Ground

--

1

1

--

Left Rear Stop/Turn Lamp Ground

--

1

1

--

Right Rear Stop/Turn Lamp Ground

--

1

1

--

1. Stop Lamps Malfunction

Circuit/System Description

The brake pedal position sensor is used to sense the action of the driver application of the brake pedal. The brake pedal position sensor provides an analog voltage signal that will increase as the brake pedal is applied. The body control module (BCM) provides a low reference signal and a 5-volt reference voltage to the brake pedal position sensor. When the variable signal reaches a voltage threshold indicating the brakes have been applied, the BCM will apply battery voltage to the right and left stop lamp control circuits, transmission control module (TCM), engine control module (ECM), and center high mounted stop lamp (CHMSL) control circuit. For more detailed information concerning stop lamp operation refer to Exterior Lighting Systems Description and Operation .

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

DTC C0297 00 will set when the BCM detects a short to ground, short to voltage, or an open/high resistance in the stop lamp switch signal circuit.

Actions 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.
    • You issue a scan tool CLEAR DTCs command.
    • A history DTC will clear once 40 malfunction-free ignition cycles have occurred.

Diagnostic Aids

Important: The stop lamps will not illuminate unless the ignition is in the ON position. For more detailed information concerning stop lamp operation, refer to Exterior Lighting Systems Description and Operation .

Verify that the brake pedal position sensor is properly calibrated.

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 Testing

  1. Ignition OFF, disconnect the harness connector at the BCM.
  2. Connect a test lamp between the stop lamp switch signal circuit and ground.
  3. Ignition ON, command the stop lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
  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 is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. Ignition OFF, connect a test lamp between the stop lamp switch signal circuit and the connector terminal at the BCM.
  6. Ignition ON, command the stop lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
  7. If the test lamps does not operate as described, replace the BCM.
  8. Ignition OFF, reconnect the BCM harness connector.
  9. Disconnect the harness connector at the TCM.
  10. Connect a test lamp between the stop lamp switch signal circuit and ground.
  11. Ignition ON, command the stop lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
  12. 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 is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  13. If all circuits test normal, replace the TCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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