Circuit Operation

The Brake/Transmission Shift Interlock requires that the brake pedal be depressed before the automatic transmission may be shifted from Park position. Once the transmission is placed in Park, and the Ignition Switch is in RUN or START, current flows from TURN B/U Fuse 16 through the contacts of the Park/Neutral Position Switch (closed-in-Park), through the TCC/Stoplamp Switch, and through the Brake/Transmission Shift Interlock Solenoid to Ground G200. The solenoid is energized preventing the transmission from being placed in another gear. When the brake pedal is actuated, the normally-closed contacts in the TCC/Stoplamp Switch open. Current flow is stopped and the Brake/Transmission Shift Interlock Solenoid is deenergized. The transmission may be placed in another gear. Once the transmission is in any other gear, the contacts in the Park/Neutral Position Switch are open and no current can flow to energize the solenoid when the brake pedal is released.

Important: The Brake/Transmission Shift Interlock Solenoid is energized through the Stoplamp Switch Pins E and F with the Brake Pedal in the released position. Actuating the Brake Pedal opens the Stoplamp Switch, causing the Brake/Transmission Shift Interlock Solenoid to de-energize, unlocking the Transmission Shift Lever. The lock-out function is only active with the Ignition Key in the RUN or START position.