Sensor, Stop Lamp: Operation

The brake pedal position sensor monitors changes in the brake pedal position relative to the brake pedal mounting bracket. The sensor circuitry is energized by the Antilock Brake System (ABS) module and provides hardwired analog (potentiometer) inputs back to the ABS module. The ABS module uses the sensor inputs directly as additional logic for many of the ABS, Electronic Stability Control (ESC) and Brake Assist System (BAS) features.

The ABS module also sends electronic brake lamp switch status  messages to other electronic modules in the vehicle over the Controller Area Network (CAN) data bus. Other electronic modules use this information as an additional logic input for controlling many other vehicle functions and features, including the Body Control Module (BCM) for control of the brake (or stop) lamps.

The hardwired circuits between the brake pedal position sensor and the ABS module may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the brake pedal position sensor or the electronic controls and communication that provide some features related to brake pedal position sensor operation. The most reliable, efficient and accurate means to diagnose the brake pedal position sensor or the electronic controls and communication related to sensor operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.