The Bendix+ ATR-6 Antilock Traction Relay valve is a service relay valve fitted with a modified cover containing a Control Solenoid. It contains both air and electric components to provide the service braking and traction control (differential braking) as well as ESP+ advanced stability system ABS functions. Typically the ATR-6 valve replaces a standard relay valve used to control the rear axle service brakes, though it may be used for both front and rear axles on some advanced ABS vehicle applications. In normal operation, it performs the standard relay function and like the standard relay valve it replaces. The ATR-6 valve is normally mounted near the service brakes it serves. When the ABS Controller operates the ATR-6 valve, for example during an antilock traction event, the Control Solenoid is energized and permits delivery air to be supplied to the Antilock Modulator Valves and used as required by the Controller.