Shift Interlock: Description and Operation

Shift Interlock System






1 Lock

2 Acc

3 On

4 Start

The brake transmission shift interlock is a solenoid operated system that prevents the transmission gear shift from being moved out of park without a driver in place.

The BTSI is engaged whenever the ignition switch is in the lock (1) or ACC (2) position. An additional electrically activated feature will prevent shifting out of the park position unless the brake pedal is depressed at least one half inch. When the key is in the on (3) position and the brake pedal is depressed, the shift lever is unlocked and will move into any position.






When the brake pedal is not depressed the solenoid rotating arm (2) is free to rotate. The shift gate pin (1) hits the blocking arm (3) and is prevented from moving from park.

When the brake pedal is applied the rotating arm (2) is prevented from rotating by magnetic force within the solenoid. The shift gate pin (1) pushes the rotating arm (2) and blocker arm (3) allowing the shift lever to move out of park.