The Brake Pedal Position (BPP) switch (Figure 21) is used by the PCM to disengage the transmission torque converter clutch and on some applications as an input to the idle speed control for idle quality. On most applications the BPP switch is hard wired to the PCM and supplies battery positive voltage (B+) when the vehicle brake pedal is applied. On other applications the BPP switch signal is broadcast over the SCP link via another module to be received by the PCM.
On applications where the BPP switch is hard wired to the PCM and stoplamp circuit, if all stoplamp bulbs are burned out (open), 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 stop amp bulbs has failed.