Brake Shift Interlock System
WARNING: This page is about a different car, the 2009 Ford RV Cutaway, 2009 Ford Econoline, 2009 Ford E450 Super Duty, and 2009 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The brake shift interlock system prevents the selector lever to be shifted from the PARK position unless the brake pedal is applied. The brake shift interlock system consists of a Brake Shift Interlock Actuator (BSIA) mounted on the steering column tube. When the ignition switch is in the RUN position, the BSIA solenoid is off until the brake pedal is applied.