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 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 key 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 depress the brake pedal, battery voltage is applied through the GRN/WHT wire to the engine control module (ECM).

As long as the accelerator pedal is not depressed, a low voltage signal is sent through the RED/BLU wire to the ECM. When the brake pedal is depressed (with the accelerator released) the ECM shift lock circuit control output 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 a ground to the shift lock solenoid. The solenoid is then energized, and the A/T gear position switch can be moved from the park position.