Shift Interlock: Description and Operation

A/T Key Interlock
Battery voltage is supplied at all times through fuse 45 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 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 transistor is grounded at G401. With the transistor OFF, the solenoid is not energized and the key can be removed from the ignition.

A/T Gear Lever Interlock
Battery voltage is supplied at all times through fuse 45 to the brake switch. With the ignition in ON (II) or START (III), battery voltage is supplied through fuse 5 to the shift lock solenoid. When you push on the brake pedal, battery voltage is applied through the GRN/WHT wire to the Transmission Control Module (TCM). When the accelerator pedal is NOT pressed, a low voltage signal is sent through the RED/YEL wire to the TCM. When you push on the brake pedal with the accelerator released, the TCM shift lock relay control terminal applies voltage through the ORN/BLK wire to the shift lock relay in the interlock control unit. If the A/T gear position switch is in PARK, the relay is energized and the contacts close, energizing the shift lock solenoid and allowing the shift lever to be moved from PARK.