B0655

DTC B0655

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC B0655 5a
- Center Brake Light Circuit Short to Ground




Diagnostic Fault Information






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 receives B+ voltage from the underhood electrical center (UEC) from the F16 fuse. When the brake pedal is applied, the brake pedal position sensor switch contacts close. With the switch contacts closed, B+ voltage flows through the brake pedal position sensor signal circuit to the rear electrical center (REC), electronic brake control module (EBCM), engine control module (ECM), shift lock solenoid, and transmission control module (TCM). The REC responds by applying voltage to the left and right stop/turn lamp control circuits as well as the center high mounted stop lamp (CHMSL) control circuit illuminating the brake lamps.


Conditions for Running the DTC

* Battery voltage must be between 9-16 volts.
* Brakes APPLIED.



Conditions for Setting the DTC

DTC B0655 5a will set when the REC detects a short to voltage, short to ground, or an open/high resistance in the brake pedal position sensor signal circuit when the stop lamps are being commanded ON.


Actions Taken When the DTC Sets

The REC will store the DTC to memory.


Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 100 malfunction-free ignition cycles have occurred.



Reference Information
Schematic Reference

Exterior Lights Schematics (Exterior Lights Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the brake pedal position sensor.
2. Ignition OFF, test for greater than 11.0 volts between the control circuit terminal 1 and ground.

• If less than the specified value, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the UEC.

3. Ignition OFF, test for greater than 11.0 volts between the control circuit terminal 3 and ground.

• If less than the specified value, test the control circuit for a short to ground or an open/high resistance.

4. With a scan tool, verify the control module inputs listed below display INACTIVE.

* Body exterior lighting/turn indicator system brake switch
* Electronic brake control module (EBCM) brake light switch 1
* Electronic brake control module (EBCM) brake light switch 2
* Engine control module (ECM) brake switch 1
* Engine control module (ECM) brake switch 2
* REC brake switch
* Transmission control module (TCM) brake switch


• If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the appropriate control module.

5. Install a 3A fused jumper wire between the control circuit terminal 1 and the signal circuit terminal 2. Verify the control module inputs listed below display ACTIVE.

* Body exterior lighting/turn indicator system brake switch
* Electronic brake control module (EBCM) brake light switch 2
* Engine control module (ECM) brake switch 1
* REC brake switch
* Transmission control module (TCM) brake switch


• If not the specified value, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the appropriate control module.

6. Install a 3A fused jumper wire between the control circuit terminal 3 and the signal circuit terminal 4. Verify the control module inputs listed below display ACTIVE.

* Electronic brake control module (EBCM) brake light switch 1
* Engine control module (ECM) brake switch 2


• If not the specified value, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the appropriate control module.

7. If all circuits test normal, replace the brake pedal position sensor.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Stop Lamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for EBCM, ECM, REC, or TCM replacement, setup, and programming