• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Body Control Module (BCM) 5 Fuse B+ | 1, 2 | 1, 2 | -- | -- |
Body Control Module (BCM) 6 Fuse B+ | 1, 2 | 1, 2 | -- | -- |
Stop Lamp Relay Switch B+ - European | 2 | 2 | -- | -- |
Brake Position Sensor 5-Volt Reference | C0277 06, C0890 03 | C0277 06, C0890 03 | 1, 2 | -- |
Brake Position Sensor Signal | C0277 06, 07 | C0277 06 | C0277 07 | C0277 09 |
Center High Mounted Stop Lamp (CHMSL) Control | B3445 00 | 2 | 2 | -- |
Stop Lamp Relay Control - European | B3445 00 | 2 | 2 | -- |
Left Rear Stop/Turn Lamp Control | 1, 2 | 1, 2 | 1, 2 | -- |
Right Rear Stop/Turn Lamp Control | 1, 2 | 1, 2 | 1, 2 | -- |
Brake Position Sensor Low Reference | -- | C0277 06 | 1, 2 | -- |
Center High Mounted Stop Lamp (CHMSL) Ground | -- | 1, 2 | 1, 2 | -- |
Left Rear Stop/Turn Lamp Ground | -- | 1, 2 | 1, 2 | -- |
Right Rear Stop/Turn Lamp Ground | -- | 1, 2 | 1, 2 | -- |
Stop Lamp Relay Ground - European | -- | 2 | 2 | -- |
1. Stop Lamps Malfunction - North America 2. Stop Lamps Malfunction - European |
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.
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 stop lamp relay coil side control circuit, transmission control module (TCM), engine control module (ECM), and center high mounted stop lamp (CHMSL). When the stop lamp relay receives battery voltage from the BCM, the relay coil is energized and the stop lamp relay switch contacts close applying battery voltage from the STOP LAMPS fuse to illuminate the rear stop lamps and trailer stop lamps.
Battery voltage must be between 9-16 volts.
The DTC will set when the BCM detects an open or short to ground in the brake pedal position sensor signal circuit for 0.5 second or greater.
The DTC will set when the BCM detects a short to battery voltage or a short to ground in the brake pedal position sensor signal or low reference circuits for 0.5 seconds or greater.
The DTC will set when the BCM detects the brake pedal position sensor signal is changing faster than possible under normal operating conditions.
The DTC will set when the brake pedal position sensor home position is not learned.
• | The Service Vehicle Soon indicator is commanded ON. |
• | 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. |
• | For DTC C0277 4B the stop lamps may not activate at the expected brake pedal positions. |
• | 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 DTC will not clear the current status until the next ignition cycle. |
• | A history DTC will clear once 50 malfunction-free ignition cycles have occurred. |
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.
If the DTC is set, replace the brake pedal position sensor. If the DTC resets, replace the BCM.
If the DTC is set, recalibrate the brake pedal position sensor.
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
⇒ | If the test lamp does not illuminate, test the low reference circuit for an open/high resistance. |
⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | If greater than the specified range, test the signal circuit terminal A for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If the DTC resets, replace the BCM. |
⇒ | If the DTC resets, replace the brake pedal position sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |