Circuit Operation

When the Brake Transmission Shift Interlock (BTSI) is energized, the Solenoid locks the Shift lever mechanism in PARK. When not energized, the BTSI Solenoid returns to the unlocked position.

The Components involved in the BTSI Circuit are as follows:
^ Park/Neutral Position and Backup lamp Switch
^ TCC/Stoplamp Switch
^ BTSI Solenoid

Fuse #16 (TURN-B/U) supplies battery voltage (12V) from the Ignition Switch to the Park/Neutral Position and Backup lamp Switch, then to the TCC/Stoplamp Switch and on the BTSI Solenoid. With the Ignition Switch in the RUN or START position, the Shift Lever in PARK, and the Brake Pedal released, the Solenoid is energized. This locks the Shift Lever in PARK.

Important: The BTSI portion of the TCC/Stoplamp Switch (Terminals E & F) contacts are CLOSED with the Brakes released. Depressing the Brake Pedal opens the Switch contacts causing the Solenoid to de-energize, unlocking the Shift lever. The BTSI portion of the Park/Neutral Position and Backup Lamp Switch contacts (Terminals B & C) are closed in the PARK position only. The Circuit is not active with the key OFF.