"ASR" stands for anti-skid recognition.When ASR is activated, the system can sense when the speed of one wheel differs from the others causing a skid and can adjust braking automatically to stop the skid.
〉 Answered on Oct 4th, 2012 by Colleen McGee, Driving Instructor at Americas Driving School
VW calls it Anti Spin Regulations. It is a traction control system for slippery surfaces.
〉 Answered on Oct 4th, 2012 by Jo An Holt, Automotive Journalist at Holt & Associates
Mike, a traction control system (TCS), also known as anti-slip regulation (ASR), is typically (but not necessarily) a secondary function of the Anti-Lock Braking System (ABS). The general idea is to reduce the torque of your wheels when accelerating to reduce and prevent slipping of the tires. Turning the system off will give you full performance and maximum torque. The main benefit of this system is on icy, snow covered or wet roads.