How can I diagnose a malfunctioning ABS in an Audi 80?

I recently noticed that the ABS light on my Audi 80 is constantly on, and I am concerned about the safety and performance of my brakes. What steps should I take to diagnose and fix the issue?

Firstly, check if there are any fault codes stored in the ABS module. This can be done using an OBD-II scanner or by taking the car to a mechanic.

Next, inspect the ABS sensors and connections on all four wheels. These can become corroded or damaged, causing the ABS to malfunction.

If the sensors and connections appear to be in good condition, it is possible that the ABS module itself is faulty and may need to be replaced.