Brake Switch - TCC: Description and Operation

Circuit K29 connects between the Powertrain Control Module (PCM) and the stop lamp switch. The K29 circuit connects to cavity 29 of the PCM.

The PCM uses this input along with inputs from the Throttle Position Sensor (TPS) and Vehicle Speed Sensor (VSS) to adjust the Idle Air Control (IAC) motor during vehicle deceleration.