How to troubleshoot a faulty ABS system in an Audi 80?

I recently encountered an issue with my Audi 80's ABS system. The ABS warning light keeps coming on and off while driving. What could be causing this and how can I fix it?

One possible cause for this issue could be a faulty ABS sensor. These sensors can become worn out or damaged over time, resulting in erratic system behavior. I recommend getting the sensor checked and replaced if necessary.

Another potential cause could be a malfunctioning ABS module. This component controls the ABS system and if it fails, the system will not function properly. Have a mechanic run a diagnostic test to identify and replace the faulty module.

It's also possible that air has entered the ABS system, causing a loss of pressure and triggering the warning light. Have a specialist bleed the brake system to remove any air and restore proper function to the ABS.