Shift Interlock: Description and Operation

Key Interlock
Battery voltage is supplied at all times through fuse 42 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. When the A/T gear position switch is in PARK, ground is provided to the key interlock circuit. This removes ground from the interlock solenoid, the solenoid is deenergized, and the key can be removed 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 Transmission Control Module (TCM). If, at the same time, you do not push the accelerator pedal, a low voltage signal is sent through the RED/BLK wire to the TCM. The TCM then 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 the shift lever can be moved from the PARK position.