Shift Interlock: Description and Operation

Interlock System

How the Circuit Works

Key Interlock

Voltage is supplied at all times to the brake pedal position switch and to the park pin relay through fuse 47 (in the under-hood fuse/relay box). When you push the key into the ignition switch, battery voltage is provided to the key interlock solenoid. When you shift out of PARK, the park pin switch provides ground to the key interlock solenoid, energizing the solenoid and allowing the key be turned to the LOCK (0) position.

Shift Position Interlock

With the ignition in A/C (I) or ON (II), battery voltage is supplied through fuse 9 (in the driver's under-dash fuse/relay box) to the shift lock solenoid. When you push the brake pedal, battery voltage is applied through the WHT/BLK wire to the PCM. The PCM then applies a ground through the WHT/RED wire to the shift lock solenoid. The solenoid is then energized allowing the shift lever to be moved from the PARK position.

If the PCM senses any movement of the accelerator pedal or the accelerator pedal is not in the idle position, the shift lock solenoid will not be energized. For safety reasons, the shifter cannot be moved from the park position.