The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components.

With the ignition ON, battery positive voltage is supplied to the automatic transmission shift lock control solenoid from the ignition 3 relay. The automatic transmission shift lock control solenoid is controlled by the rear integration module. When the rear integration module (RIM) receives a class 2 serial data message from the transmission control module (TCM) or powertrain control module (PCM) indicating that the shift lever is in the PARK position the rear integration module (RIM) grounds the automatic transmission shift lock control solenoid control circuit. This causes the solenoid to energize mechanically locking the shift lever in the PARK position. When the driver presses the brake pedal the rear integration module receives the brake applied signal and turns off the ground to the automatic transmission shift lock control solenoid control circuit. This allows the shift lever to be moved out of the PARK position.