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 consist of the following components:

With the ignition in the ON position, battery positive voltage is supplied to the automatic transmission shift lock control switch. The circuit continues through the normally-closed switch to the automatic transmission shift lock control solenoid. The body control module (BCM) provides a ground for the automatic transmission shift lock control solenoid when the transmission is in the PARK position. The body control module (BCM) receives the transmission gear position information via class2 serial data from the powertrain control module (PCM). This causes the automatic transmission shift lock control solenoid to energize and lock the shift lever in the PARK position. When the driver presses the brake pedal, the contacts in the automatic transmission shift lock control switch open. This causes the automatic transmission shift lock control solenoid to release. This allows the shift lever to move from the PARK position. The body control module (BCM) turns off the automatic transmission shift lock control solenoid ground circuit when the transmission is out of the PARK position.