Antilock Brake System

DTC C0277

Diagnostic Instructions

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

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC C0277 4B
- Brake Pedal Position Sensor Circuit Calibration Not Learned

Circuit/System Description

When the brake pedal is applied, the Body Control Module sends a serial data message to the Electronic Brake Control Module in reference to the brake pedal positions. The Electronic Brake Control Module compares the correlation between the brake pedal position and the amount of brake pressure it senses from the Brake Pressure Sensor, which is internal to the Brake Pressure Modulator. It uses this information to control the vehicle during an stability control event.

Conditions for Running the DTC

* Brakes Applied.

* Battery voltage must be between 9-16 V.

Conditions for Setting the DTC

- The Body Control Module sends invalid brake pedal position data to the Electronic Brake Control Module.

- The DTC may set in the Body Control Module and/or Electronic Brake Control Module, when the brake pedal position sensor home position is not learned.

Actions Taken When the DTC Sets

* The ABS Indicator is commanded ON.

* The red Brake Indicator is commanded ON.

* The Stability Indicator is commanded ON.

* The Traction Control Indicator is commanded ON.

* 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.

* A DTC will not clear the current status until the next ignition cycle.

* A successful brake pedal position sensor calibration has been performed.

* A history DTC will clear once 40 malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

* Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems

* Exterior Lights Schematics Exterior Lights Schematics

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

* ABS Description and Operation Description and Operation

* Exterior Lighting Systems Description and Operation Exterior Lighting Systems

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Verify DTC C0277 is not set in the K9 Body Control Module.

• If DTC is set
Refer to DTC C0277 or C0890 Lighting.

• If DTC is not set

2. Ignition ON

3. Verify the scan tool Body Control Module Brake Pedal Position Sensor Learned Released Position is YES.

• If the released position is not YES
Perform the Brake Pedal Position Sensor Calibration. Refer to Brake Pedal Position Sensor Calibration Brake Pedal Position Sensor Calibration.

• If the released position is YES

4. Verify the DTC does not set while operating the vehicle within the Conditions for Running the DTC.

• If the DTC sets
Replace the K17 Electronic Brake Control Module.

• If the DTC does not set

5. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

Control Module References Control Module References for Electronic Brake Control Module replacement, programming and setup