Circuit Operation - Brake to Shift Indicator

On Buick only, the park/neutral position switch also contains a transaxle range switch. This component is a multi-signal switch which sends information relative to gear selector position to the Powertrain Control Module (PCM) via four discrete circuits. The PCM in turn, sends a signal over the UART data line to the instrument cluster. If the instrument cluster receives a PARK signal from the PCM, it turns on the BRAKE TO SHIFT indicator. If it receives any other signal, the indicator does not light.

Important: On vehicles equipped with Retained Accessory Power (RAP), open any door to remove battery voltage at the solenoid. Refer to Steering Wheel and Column On-Vehicle Service for further information.