Description & Operation: Introduction

The automatic transmission shift lock control 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 gearshift lever out of the Park position. The system consists of the following components:

• Shift lock solenoid.
• Shift lock control switch (stoplamp switch).
• Park relay (located in the rear fuse block).
• Rear Integration Module (RIM).

With the ignition switch in the ON position, battery voltage is supplied to the park relay. When the RIM energizes the park relay, the park relay switch contacts close suppling battery voltage to the stoplamp switch. The circuit continues through the normally closed switch to the shift lock 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 stoplamp switch open. This causes the shift lock solenoid to release. This allows the gearshift lever to move from the Park position.

A mechanical locking mechanism prevents the gearshift lever from moving out of the Park position when the key is in the OFF position. With the key in the ACC position, the mechanical lock is disabled allowing the gearshift lever to be moved out of the Park position. This will override the shift lock control system in the event the vehicle must be moved with the engine off.