Buick Regal: DTC C0277 or C0890

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 C0277 06

Brake Pedal Position Sensor Circuit Low Voltage/Open

DTC C0277 07

Brake Pedal Position Sensor Circuit High Voltage

DTC C0277 09

Brake Pedal Position Sensor Circuit Too Fast Transitions

DTC C0277 4B

Brake Pedal Position Sensor Circuit Calibration Not Learned

DTC C0890 03

Control Module Voltage Reference Output 3 Circuit Low Voltage

DTC C0890 07

Control Module Voltage Reference Output 3 Circuit High Voltage

Diagnostic Fault Information

1. Stop Lamps Malfunction
2. Center High Mounted Stop Lamp 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 provides a low reference signal and a 5 V 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 left and right stop lamp control circuits as well as the center high mounted stop lamp control circuit illuminating the left and right stop lamps and the center high mounted stop lamp.

Conditions for Running the DTC

• Battery voltage must be between 9 - 16 V.
• Brakes APPLIED.

Conditions for Setting the DTC

DTC C0277 06

• The BCM detects a short to ground or an open/high resistance in the brake pedal position sensor 5 V reference circuit.
• The BCM detects a short to ground or an open/high resistance in the brake pedal position sensor signal circuit.

DTC C0277 07

• The BCM detects a short to voltage in the brake pedal position sensor 5 V reference circuit.
• The BCM detects a short to voltage in the brake pedal position sensor signal circuit.
• The BCM detects an open/high resistance in the brake pedal position sensor low reference circuit.

DTC C0277 09

The BCM detects the brake pedal position sensor signal is changing faster than possible under normal operating conditions.

DTC C0277 4B

The DTC will set when the brake pedal position sensor home position is not learned.

DTC C0890 03

The BCM detects a short to ground in the brake pedal position sensor 5 V reference circuit.

DTC C0890 07

The BCM detects a short to voltage in the brake pedal position sensor 5 V reference circuit.

The BCM detects a short to voltage in the brake pedal position sensor low reference circuit.

Actions Taken When the DTC Sets

• The Traction Control indicator is commanded ON.
• For DTC C0277 4B, the stop lamps may not activate at the expected brake pedal positions.

Conditions for Clearing the DTC

• The condition responsible for setting the DTC no longer exists.
• For DTC C0277 07 the ignition must be cycled before the code can be cleared.
• For DTC C0277 4B a successful brake pedal position sensor calibration has been performed.
• A history DTC will clear once 50 malfunction-free ignition cycles have occurred.
• A DTC will not clear the current status until the next ignition cycle.

Reference Information

Schematic Reference

Exterior Lights Wiring Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Exterior Lighting Systems Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Testing

DTC C0277 or C0890

1. Ignition OFF, disconnect the harness connector at the B22 Brake Pedal Position Sensor, ignition ON.

2. Verify a test lamp illuminates between low reference circuit terminal 1 and B+.

• If the test lamp does not illuminate

1. Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module.
2. Test for less than 2 Ω in the low reference circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K9 Body Control Module.

• Go to next step: If the test lamp illuminates

3. Ignition ON.

4. Test for 4.8 - 5.2 V between 5 V reference circuit terminal 2 and ground.

• If less than 4.8 V

1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the 5 V reference circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.

• Go to next step: If infinite resistance

3. Test for less than 2 Ω in the 5 V reference circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K9 Body Control Module.

• If greater than 5.2 V

1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the 5 V reference circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K9 Body Control Module.

• Go to next step: If between 4.8 - 5.2 V

5. Verify the scan tool Brake Pedal Applied parameter is Inactive.

• If not Inactive

1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between signal circuit terminal 3 and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K9 Body Control Module.

• Go to next step: If Inactive

6. Install a 3 A fused jumper wire between the appropriate 5 V reference and signal circuit terminal 3.

7. Verify the scan tool Brake Pedal Applied parameter is Active.

• If not Active

1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between signal circuit terminal 3 and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in the signal circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K9 Body Control Module.

• Go to next step: If Active

8. Test or replace the B22 Brake Pedal Position Sensor.

DTC C0277 4B

1. Verify DTC C0277 4B is not set.

• If DTC C0277 4B is set

1. Ignition ON
2. Perform the brake pedal position sensor calibration procedure for the K9 Body Control Module. Refer to Brake Pedal Position Sensor Calibration.
3. Verify the DTC does not reset while operating the vehicle under the conditions for setting the DTC.
   • If the DTC resets, replace the B22 Brake Pedal Position Sensor.
   • Go to next step: If the DTC does not reset
4. All OK.

• Go to next step: If DTC C0277 4B is not set

2. All OK.

DTC C0277 09

1. Verify DTC C0277 09 is not set.

• If DTC C0277 09 is set

1. Replace the B22 Brake Pedal Position Sensor.
2. Perform the brake pedal position sensor calibration procedure for the K9 Body Control Module. Refer to Brake Pedal Position Sensor Calibration.
3. Verify the DTC does not reset while operating the vehicle under the conditions for running the DTC.
   • If the DTC resets, replace the K9 Body Control Module.
   • Go to next step: If the DTC does not reset
4. All OK.

• Go to next step: If DTC C0277 09 is not set

2. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

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

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