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 drive must press the brake pedal before moving the shift lever out of 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 and park lock solenoids. The transmission range switch provides a path to ground in the PARK position. With the automatic transmission shift lock control and park lock solenoids energized the shift lever is locked 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 and park lock solenoids to release. This allows the shift lever to move from the PARK position.