Brake Pedal Position (BPP) Switch
WARNING: This page is about a different car, the 2005 Jaguar XJR, 2005 Jaguar XJ8, 2004 Jaguar XJR, and 2004 Jaguar XJ8. However, it is still accessible from the selected car via links, so may be relevant.
The brake pedal position (BPP) switch tells the TCM when the brakes are applied, and disengages torque converter clutch. The BPP switch closes when the brakes are applied and opens when they are released. The BPP is also used to disengage the brake shift interlock and stops gradient calculations.