Shift Interlock: Description and Operation
How the Circuit WorksKey Interlock
Voltage is supplied at all times to the key interlock switch through fuse 47. When you push the key into the ignition switch, battery voltage is provided to the key interlock solenoid. When you shift out of PARK, ground is provided to the solenoid through the park pin switch. This energizes the solenoid and prevents the key from being turned back to the LOCK position so the key can not be removed from the ignition switch.
Shift Position Interlock
Battery voltage is supplied at all times through fuse 47 to the brake pedal position switch. With the ignition in ON (II) or START (III), battery voltage is supplied through fuse 9 (in the driver's under-dash fuse/relay box) to the shift lock solenoid. When you push the brake pedal, battery voltage is applied through the WHT/BLK wire to the PCM. If, at the same time, you do not push the accelerator pedal, a low voltage signal is sent through the RED/BLK wire to the PCM. The PCM then applies voltage through the WHT/RED wire to the shift lock circuit in the driver's multiplex control unit. When you move the A/T shift lever from the PARK position, ground is provided to the shift lock solenoid. The solenoid is then energized allowing the shift lever to be moved from the PARK position.