Shift Interlock: Description and Operation

COLUMN SHIFTING
The Brake Transmission Shift Interlock (BTSI) is designed to prevent shifting out of PARK without depressing the brake pedal. The BTSI Solenoid is energized when the Ignition Switch is in OFF, RUN, BULB TEST or START and is de-energized when the brake pedal is depressed. The Stoplamp Switch receives ignition voltage in OFF, RUN, BULB TEST or START from the BTSI Fuse. The Stoplamp Switch is normally closed, providing voltage through circuit 1135 to the BTSI Solenoid, energizing the solenoid and mechanically locking the Transmission Shift Lever whenever it is in PARK. When the brake pedal is depressed, the Stoplamp Switch opens, removing voltage from circuit 1135 to the BTSI Solenoid. This de-energizes the BTSI Solenoid, allowing the vehicle to be moved out of the PARK position.

CONSOLE SHIFTING
The Brake Transmission Shift Interlock (BTSI) is designed to prevent shifting out of PARK without depressing the brake pedal. The BTSI Solenoid and the Park Lock Solenoid are energized when the Ignition Switch is in OFF, RUN, BULB TEST or START. When the Park Lock Solenoid is energized, the mechanical lock connected to this solenoid is pulled away from the shifter. The Stoplamp Switch receives ignition voltage in OFF, RUN, BULB TEST or START from the BTSI Fuse and is normally closed, providing voltage through circuit 1135 to the BTSI Solenoid, energizing the solenoid and mechanically locking the Transmission Shift Lever whenever it is in PARK. When the brake pedal is depressed, the Stoplamp Switch opens, removing voltage from circuit 1135 to the BTSI Solenoid. The BTSI Solenoid is deenergized and the mechanical lock connected to the BTSI Solenoid pulls back from the shifter, allowing shifting.

COLUMN LOCK
On vehicles with the console shift, there is a lock on the Ignition Key Cylinder, preventing the user from removing the key while in a NON-PARK position until the vehicle has returned to the PARK position.