Brake Shift Interlock Operation
WARNING: This page is about a different car, the 2010 Lincoln MKX and 2010 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
The BSIA inhibits the selector lever movement from the PARK position by mechanically blocking the detent pawl of the selector lever mechanism. When the brake pedal is depressed (BPP switch closed) with the ignition key in the RUN/START position and the transmission in PARK, the BSIA is energized by the SJB , this allows the selector lever to be moved out of the PARK position.