Shift Interlock: Description and Operation
How the Circuit WorksKey Interlock
When the Ignition Key is inserted into the Ignition Switch, a path to ground is provided for the IG KEY SW input to the Gauge Control Module. The Gauge Control Module detects the insertion of the Ignition Key through this input. When the Shift Lever is moved from Park (P), a path to ground is provided for the P-PIN input to the Key Lock Circuit in the Gauge Control Module. The Key Lock Circuit detects that the Shift Lever is out of Park (P) through this input. With the Ignition Switch in ACC or ON voltage is applied through fuse 26 (in the under-dash fuse/relay box) to the Key Interlock Solenoid. The solenoid is then energized, which prevents the Ignition Switch from being turned to LOCK (0).
Shift Position Interlock
Battery voltage is supplied at all times through fuse 16 (in the under-hood fuse/relay box) to the brake pedal position switch. With the Ignition Switch in ON (II) or START (III), battery voltage is supplied through fuse 3 (in the under-dash fuse/relay box) to the Shift Lock Solenoid. When the Brake Pedal is pressed, a battery voltage input is supplied to the PCM. If, at the same time, the accelerator pedal is not pressed, the PCM provides ground to the Shift Lock Solenoid. The solenoid is then energized allowing the Shift Lever to be moved.