Shift Interlock: Description and Operation

Key Interlock


Battery voltage is supplied at all times through fuse 42 to the key interlock switch. When you put the key in the ignition switch, battery voltage is applied to the key interlock solenoid and to the key interlock circuit in the interlock control unit. When the A/T gear position switch is in PARK, ground is provided to the key interlock circuit. The interlock circuit then removes ground from the solenoid, de-energizing it. You can then remove the key from the ignition.


Shift Position Interlock


Battery voltage is supplied at all times from fuse 42 to the brake switch. With the ignition in ON (II) or START (III), battery voltage is supplied through fuse 15 to the shift lock solenoid. When you push the brake pedal, battery voltage is applied through the GRN/WHT wire to the engine control module (ECM).

As long as you don't push the accelerator pedal, a low voltage signal is sent through the RED/BLU wire to the ECM. When you push the brake pedal (without touching the accelerator) the shift lock circuit control output in the ECM applies voltage through the WHT/RED wire to the shift lock circuit in the interlock control unit. If the A/T gear position switch is in the PARK position, the shift lock circuit provides ground to the shift lock solenoid. The solenoid is then energized, and you can then move the A/T gear position switch from the PARK position.