ABS malfunctions (Audi 100 C4)

If the ABS is deactivated, the ABS indicator lights up on the instrument panel. If the engine is switched off and then restarted during this time, the ABS is automatically switched on again. When the ignition is switched on, the ABS indicator lights up on the instrument panel. It should go out if the engine is running, or at the latest if the vehicle is moving at a speed of more than 6 km/h. If the on-board voltage drops below 10 V, the indicator lights up again. It can also flash if one wheel spins for more than 20 seconds. In this case, switch the ignition off and on again, and start the engine. If the indicator lights up continuously, the ABS is faulty. Contact an Audi or Bosch workshop. At home, you can only check the plug connections to the control unit, to the speed sensors or to the hydraulic unit.

Hint: Even if the ABS indicator is constantly on, which means the anti-lock braking system is disabled or faulty, the car can be used without restrictions. The braking system functions in this case as in a car without ABS.