Patent ID: 8340853

Claim:
A motor vehicle comprising: wheels on which the vehicle travels; a powertrain delivering propulsion torque to at least some of the wheels to propel the vehicle; a service brake system comprising service brakes that when applied by a service brake actuator are effective to impart braking torque to at least some of the wheels; an electrical system; a first device providing velocity data representing a velocity that correlates with rotational velocity of a wheel; a second device associated with the service brake actuator providing data that distinguishes between application and non-application of the service brakes by the service brake actuator; and a processor which operates i) to differentiate velocity data provided by the first device to produce deceleration data, ii) to compare the deceleration data with a deceleration threshold value which demarcates deceleration large enough to indicate application of the service brakes from smaller decelerations which do not indicate application of the service brakes, and iii) to signal a fault in at least one of the second device and circuitry connecting the second device to the electrical system when comparison of the deceleration data with the deceleration threshold value indicates application of the service brakes while the second device is disclosing that the service brakes are not being applied.