Shift Interlock: Description and Operation

DESCRIPTION

Floor Shift
The Brake Transmission Shifter/Ignition Interlock (BTSI) is a cable and solenoid operated system that prevents the transmission gear shifter from being moved out of PARK without a driver in place.





Refer to the chart that expected shifter response, depending on ignition key/switch (Fig. 342) and brake pedal positions.

Column Shift





Vehicles equipped with a column shifter utilize a Brake Transmission Shift Interlock (BTSI) solenoid, which prevents the transmission gear shifter from being moved out of PARK without a driver in place (Fig. 343).

OPERATION





The Brake Transmission Shifter/Ignition Interlock (BTSI) is engaged whenever the ignition switch is in the LOCK or ACCESSORY position (Fig. 344). An additional electrically activated feature will prevent shifting out of the PARK position unless the brake pedal is depressed at least one-half inch. A magnetic holding device integral to the interlock cable is energized when the ignition is in the ON/RUN position. When the key is in the ON/RUN position and the brake pedal is depressed, the shifter is unlocked and will move into any position. The interlock system also prevents the ignition switch from being turned to the LOCK or ACCESSORY position, unless the shifter is in the gated PARK position.
The chart describes the normal operation of the Brake Transmission Shift Interlock (BTSI) system. If the "expected response" differs from the vehicle's response, then system repair and/or adjustment is necessary.