The brake transmission shift interlock (BTSI) system prevents the automatic transmission from being shifted out of PARK unless the brake pedal is depressed. When the brake pedal is depressed, the BTSI solenoid releases a lock pawl. This enables the movement of the shift linkage and the operation of the shift lever.

When service operations are required, overriding the BTSI is possible. In order to override the BTSI, turn the ignition switch to OFF (not LOCK), and remove the battery voltage from the solenoid.