Shift Interlock: Description and Operation

Interlock System

How the Circuit Works

Key Interlock
When the shift lever is moved out of PARK (P), the MICU provides voltage to the key interlock solenoid. The solenoid is then energized, which prevents the ignition switch from being turned to LOCK (0).

When the shift lever is returned to PARK (P), the MICU removes voltage from the key interlock solenoid, allowing the ignition switch to be turned to LOCK (0).

Shift Position Interlock
Battery voltage is supplied at all times through fuse 13 (in the under-hood fuse/relay box) to the brake pedal position switch. With the ignition switch in ACC (I) or ON (II), battery voltage is supplied through fuse 32 (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 and the MICU. 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.

When the shift lever is moved from PARK (P), a path to ground is provided for the P-PIN input to the PCM and the the MICU. The PCM and the MICU detect that the shift lever is out of PARK (P) through this input.