Shift Interlock: Description and Operation

Battery voltage is supplied at all times through fuse 39 to the key interlock switch. When the key is in the ignition, battery voltage is supplied to the key interlock solenoid and the key interlock circuit in the interlock control unit. If the A/T gear position switch is in any position but PARK, battery voltage is applied to the base of the transistor. With the transistor ON, the solenoid is energized and the key cannot be removed from the ignition. When the A/T gear position switch is in PARK, the base of the transistor is grounded through the switch. With the transistor OFF, the solenoid is not energized and the key can be removed from the ignition.

Shift Position Interlock
Battery voltage is supplied at all times through fuse 39 to the brake switch. With the ignition in ON (II) or START (III), battery voltage is supplied through fuse 13 to the shift lock solenoid. When you push the brake pedal, battery voltage is applied through the GRN/WHT wire to the Powertrain Control Module (PCM). When the accelerator pedal is not pushed, a low voltage signal is sent through the RED/BLU wire to the PCM. When you push the brake pedal with the accelerator released, the PCM sends a shift lock relay control signal through the BLU/BLK wire to the shift lock relay in the interlock control unit. If the A/T gear position switch is in the PARK position, the relay is energized and its contacts close. The shift lock solenoid is then energized and the A/T gear position lever can be moved out of PARK.