F 350 4WD Super Duty V8-6.4L DSL Turbo (2008)
Brake Light Switch: Description and Operation
BRAKE PEDAL POSITION (BPP) SWITCH
Brake Pedal Position (BPP) Switch
The BPP switch signals the PCM with a battery positive voltage (B+) signal whenever the brake pedal is applied. The signal informs the PCM to
disengage the torque converter clutch, speed control, and auxiliary idle control (if equipped).
If all the stoplamp bulbs are burned out (open), a high voltage is present at the PCM due to a pull-up resistor in the PCM. This provides fail-safe
operation in the event the circuit to the BPP switch has failed.
