• | 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 |
---|---|---|---|---|
Brake Pedal Position Sensor 10-Volt Reference | C0283, C0870 | C0277 | C0277 | -- |
Brake Pedal Position Sensor Signal | C0283 | C0277 | C0277 | -- |
Brake Pedal Position Sensor Low Reference | -- | C0277 | 1 | -- |
1. Stop Lamps Malfunction |
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 10-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 stop lamps, transmission control module (TCM), engine control module (ECM), electronic brake control module (EBCM), and center high mounted stop lamp (CHMSL).
• | Battery voltage must be between 9-16 volts. |
• | Brakes APPLIED. |
DTC C0277 will set for the following conditions:
• | The BCM detects a short to voltage or an open/high resistance in the brake pedal position sensor signal circuit. |
• | The BCM detects a short to ground or an open/high resistance in the brake pedal position sensor 5-volt reference circuit. |
• | The BCM detects an open/high resistance in the brake pedal position sensor low reference circuit. |
DTC C0278 will set when the brake pedal position sensor home position is not learned.
• | The Service Vehicle Soon indicator is commanded ON. |
• | When DTC C0277 is set as current, the vehicle will not start. |
• | 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. |
• | The condition responsible for setting the DTC no longer exists. |
• | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
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 .
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 the circuit tests normal, replace the BCM. |
⇒ | If greater than the specified range, test the 10-volt reference circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | If less than the specified range, test the 10-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 signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, 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 |