A brake system control unit controls one of first and second portions of a wheel brakes electric brake actuators to activate one of the first and second portions of the actuators and deactivate the other during an inhibited braking mode. In contact with the tip electrode, the contact force sensor has a body and has at least one sensor with an electrical characteristic that is responsive to deformation of the body resulting from force vector. In a second step, undetected faults are listed.