Shift Interlock: Description and Operation

Fig. 12 Brake Transmission Shift Interlock System:

Fig. 13 Brake Transmission Shift Interlock Key Cylinder Actuation:

OPERATION
The Brake Transmission Shift Interlock (BTSI), is a cable and solenoid operated system, Fig. 12. This system locks the transmission shift lever in the Park position preventing accidental engagement of a transmission gear before the driver has depressed the brake pedal.

OPERATION
The BTSI system is engaged whenever the ignition switch is in the Lock or Accessory position. An electrically activated magnetic holding device prevents shifting from the Park position. When the key is in the Off or Run position and with the brake pedal depressed, the shifter is unlocked and will move in any shift position, Fig. 13. The BTSI system will also prevent the ignition switch from being turned to the Lock or Accessory position if shifter is not fully locked in the Park position.