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.

Battery voltage must be between 9-16 volts.

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

If the DTC sets while the vehicle is running, the BCM will activate the brake lights when the vehicles transmission is not in the PARK position and the vehicle is not accelerating.

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.

C0277 09

If the DTC is set, replace the brake pedal position sensor. If the DTC resets, replace the BCM.

C0277 4B

If the DTC is set, recalibrate the brake pedal position sensor.

Schematic Reference

Exterior Lights Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Exterior Lighting Systems Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References

1. Ignition OFF, disconnect the harness connector at the brake pedal position sensor.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the low reference circuit terminal A.

⇒	If the test lamp does not illuminate, test the low reference circuit for an open/high resistance.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage.

4. Verify the scan tool BPP sensor parameter is less than 2 counts.

⇒	If greater than the specified range, test the signal circuit terminal B for a short to voltage.

5. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool BPP sensor parameter is greater than 1000 counts.

⇒	If less than the specified range, test the signal circuit for short to ground or an open/high resistance.

6. If all circuits test normal, test or replace the brake pedal position sensor. If the DTC resets replace the BCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.