The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the ignition is ON. 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 in the ON position, battery positive voltage is supplied to the brake to shift relay coil. When the RIM energizes the brake to shift relay, the brake to shift relay switch contacts close suppling battery voltage 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 permanently grounded solenoid is energized. This locks the shift linkage 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.