Shift Interlock: Description and Operation
Interlock SystemHow the Circuit Works
Key Interlock
When you push the key into the ignition switch, a ground signal is provided to the multiplex control unit. If the shift lever is in PARK, the multiplex control unit provides voltage to the key interlock solenoid, energizing the solenoid and allowing the key to be turned to the LOCK (0) position.
Shift Position Interlock
Battery voltage is supplied at all times through fuse 7 to the brake pedal position switch. With the ignition in ON (II) or START (III), battery voltage is supplied through fuse 10 (in the under-dash fuse/relay box) to the shift lock solenoid. When the brake pedal is pushed, battery voltage is applied to the ECM/PCM and the multiplex control unit. If, at the same time, the accelerator pedal is not pushed, ground is provided to the shift lock solenoid through the ECM/PCM. The solenoid is then energized allowing the shift lever to be moved from the PARK position.