Anti-skid system ASR (Antriebsschlupfregelung)

System ASR (from the German Antriebsschlupfregelung) is an anti-skid device that first appeared in cars in 1986. The ASR system automatically adjusts the amount of skid on one or more of the vehicle's drive wheels when starting off or accelerating. Their task is to provide control and transfer of driving forces from the wheel to the road.

The ASR can adjust the shear of both drive wheels and also interacts with the ECM during regulation. The wheel speed sensors common to the ABS monitor the speed of the driven axle. The control unit, also shared with the ABS, compares the speed with the wheel speed of the non-driving axle. If the drive wheel is slipping, the control unit receives a command to brake the wheel. If necessary, the engine control unit simultaneously issues a command to reduce the engine torque, which is carried out by automatic acceleration. This restores the wheel's rotation and again allows the driving force to be transferred to the road. Thus, the vehicle can continue to drive on slippery surfaces, as well as on roads where there are different grip conditions for the right and left wheels. The ASR system can usually be deactivated by pressing a button on the dashboard and the backlit dashboard system then informs that the system has been deactivated. The advantage for drivers of vehicles equipped with ASR is that they can drive smoothly downhill on very slippery roads, even with the accelerator pedal depressed, without significant displacement of the driving wheels.