Shift Interlock: Description and Operation
Interlock SystemHow the Circuit Works Power Supply
Fuse 11 (in the main under-hood fuse box) supplies battery voltage at all times to the brake pedal position switch. Pressing the brake pedal supplies battery voltage to the MICU (in the under-dash fuse relay box) and to the PCM.
When the ignition switch is in the ACC (I) or ON (II) position, fuse 32 (in the under-dash fuse/relay box) supplies battery voltage when the ignition switch is in the ACC or ON position to the key interlock solenoid in the ignition key switch/key light.
When the ignition switch is in the ON (II) or START (III) position, fuse 21 (in the under-dash fuse/relay box) supplies battery voltage when the ignition switch is in the ON or START position to the MICU (in the under-dash fuse/relay box) and the shift lock solenoid.
Key Interlock
The key interlock solenoid receives battery voltage when the ignition switch is in the ACC or ON position. Moving the shift lever out of PARK (P) causes the MICU to energize the key interlock solenoid. The energized solenoid prevents the ignition switch from being turned to LOCK (0). Returning the shift lever to PARK (P) causes the MICU to de-energize the key interlock solenoid, allowing the ignition switch to be turned to LOCK (0).
Shift Position Interlock
The shift lock system reduces the risk of starting the engine in gear. Starting the engine is possible only in the P and N positions. The PCM grounds the shift lock solenoid to energize the solenoid.
With the shifter in the P position while pressing the brake pedal with the throttle fully closed, the PCM energizes the shift lock solenoid, and the shift lock solenoid plunger retracts. This releases the shift lock stop and allows the shift lever to be moved.
Releasing the brake pedal or pressing the throttle causes the PCM to de-energize the shift lock solenoid, and the shifter remains locked in the P position.
Accelerating the vehicle above 6 mph (10 km/h) or decelerating above 5 mph (8 km/h) causes the PCM to de-energize the shift lock solenoid, preventing the shifter from moving into the R position.