When Audi ABS light stays on it means there is a problem with the Anti-lock Brake System (ABS). Audi ABS malfunctions can also trigger the BRAKE, ESC, or EDL lights to come on at the same time.
Under normal conditions, the ABS light will only come on for a couple of seconds when you turn on the ignition then turn off.
It is normal for Audi ABS light to flash a few times for example when the vehicle starts to slip during hard braking.
Along with the ABS light, you may also see ESP, ESC (Electronic Stability Control), EDL (Electronic Differential Lock), and Brake light.
Common problems that cause Audi ABS light to come on include:
- defective or dirty wheel speed sensor,
- control module failure,
- bad clock spring,
- low brake fluid level,
- blown fuse,
- bad ABS Pump or Module,
- Electronic Differential Lock (EDL) problem,
- the brake light switches defective.
Audi ABS light may come ON if there is a problem with the Electronic Differential Lock (EDL) as well.
ABS and Brake Light On
If both the ABS and BRAKE light stay on, the problem could be life-threatening. The brakes may not function properly.
Immediate attention is required if ABS and BRAKE lights are both staying on. If your BRAKE warning light flashes on your instrument cluster do not operate the vehicle. Audi brakes may not work or functionality can be lost while driving.
What to do when Audi ABS light stays on?
If your Audi ABS stays on the first thing you need to do is check the brake fluid level.
If the brake fluid level is normal, check the sensor on the brake fluid reservoir. The level sensor on the brake fluid reservoir may have failed.
The next step is to read codes from the ABS module.
How to Diagnose Audi ABS Light
To find out why your Audi ABS light is on, you need to read the codes from the ABS module.
To do this, you will need an OBD2 scanner that can read ABS fault codes.
What you will need
Park your Audi in a safe area.
Locate the OBD-2 port under the dashboard.
- Plug the OBD-2 scanner into the OBD2 port of your Audi.
Turn on the ignition. All Audi dashboard lights should turn on but do not start the engine. If your Audi has START/STOP button, press it twice without pressing on the brake pedal.
Turn on the scanner. Allow your Audi ABS Scan Tool to connect to the Engine Control Unit (ECU). This may take a few seconds.
- Select Audi from the menu. Next, select the Anti-lock Brake System menu.
- Read codes from the ABS module.
- Clear codes. After you fix the problem that was discovered in the previous step come back to the ABS menu and clear Audi ABS codes.
ABS Unit Failure
ABS Control Module Failure is a common issue on Audi vehicles. It triggers ABS light to come on and can affect many models including A4 and A6.
To fix this problem you will need to replace the Control Module or rebuilt your existing module. Another possible solution is to remove the ABS module from the vehicle and ship it to a company that offers Audi Control Module Rebuilt Service.