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 B0655 5a: Center Brake Light Circuit Short to GroundDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Brake Pedal Position Sensor Signal - terminal 2 | B0655 5a | B0655 5a | B0655 5a | -- |
Brake Pedal Position Sensor Signal - terminal 4 | B0655 5a | B0655 5a | B0655 5a | -- |
Brake Pedal Position Sensor Control - terminal 1 | 1 | 1 | -- | -- |
Brake Pedal Position Sensor Control - terminal 3 | 1 | 1 | -- | -- |
Center High Mounted Stop Lamp (CHMSL) Control | B3884 02 | B3884 05 | B3884 05 | -- |
Left Rear Stop/Turn Lamp Control | 1 | 1 | 1 | -- |
Right Rear Stop/Turn Lamp Control | 1 | 1 | 1 | -- |
Center High Mounted Stop Lamp (CHMSL) Ground | -- | 1 | -- | -- |
Left Rear Stop/Turn Lamp Ground | -- | 1 | -- | -- |
Right Rear Stop/Turn Lamp Ground | -- | 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 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
Connector End View Reference
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the brake pedal position sensor.
- Ignition OFF, test for greater than 11.0 volts between the control circuit terminal 1 and ground.
- Ignition OFF, test for greater than 11.0 volts between the control circuit terminal 3 and ground.
- With a scan tool, verify the control module inputs listed below display INACTIVE.
- 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.
- 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.
- If all circuits test normal, replace the brake pedal position sensor.
| ⇒ | 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. |
| ⇒ | If less than the specified value, test the control circuit for a short to ground or an open/high resistance. |
| • | 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. |
| • | 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. |
| • | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM, ECM, REC, or TCM replacement, setup, and programming |
