Audi ABS Light ON Brake Problem
Updated Tuesday Mar 20, 2018
If your Audi ABS light stays on while driving it means there is a problem with the Anti-lock Brake System (ABS). If ABS light comes on it can also trigger the BRAKE, ESC or EDL lights to come on as well. At a minimum, your Audi will not have ABS brakes but there may be other underlying problems as well. Under normal conditions, the ABS light will only come on for a couple of seconds when you turn on the ignition. ABS turns off once the engine is started. It is normal for the light to flash a few times if the vehicle starts to slip during hard braking. In this guide, you will find instructions on how to troubleshoot ABS light on Audi vehicles such as A1 A3 A4 A5 A6 A7 Q3 Q5 Q7 TT.
Along with the ABS light, you may also see ESP, ESC (Electronic Stability Control), EDL (Electronic Differential Lock) and Brake light. If the problem is critical the BRAKE light will be flashing. In most cases, your brakes will still work but it may take longer to bring the vehicle to a stop especially in emergency situation. In this guide, we will look at how to diagnose Audi ABS light and common causes that can trigger the ABS light.
If both ABS and BRAKE light stay on, the braking system may not function properly. Immediate attention is required if these two 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.
If your Audi ABS stays on the first thing you need to do is check the brake fluid level. Follow this guide to learn how to check Audi brake fluid level. If the brake fluid level is normal, next step is to read codes from the ABS module.
Diagnose Audi ABS Light
To find out why your Audi ABS light is on, you need to read the codes from the ABS module. In order to this, you will need an Audi Level 2 OBD2 scanner that can read ABS fault codes.
What you will need
Park your Audi in a safe area.
Locate OBD-2 port under the dashboard.
Plug 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.
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. Manually select the Anti-lock Brake System menu.
Read codes from the ABS module.
Once you fix the problem that was discovered in the previous step come back to the ABS menu and clear Audi ABS codes.
Audi ABS light can come on for various reasons. Common causes of Audi ABS light 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, brake light switch defective. Audi ABS light may come ON if there is a problem with the Electronic Differential Lock (EDL) as well.
ABS Light On Due to Control Module Failure
Control Module Failure is a common issue that often triggers Audi ABS light ON on models such as A4 and A6. To fix this problem you will need to replace the Control Module or rebuilt your existing module. You will need to remove your ABS module and ship it to a company of your choice that offers Audi Control Module Rebuilt Service.
Common Causes of ABS Light
- ABS Wheel Speed Sensor
- Bad ABS Relay
- Damaged Wires
- Steering angle sensor defective
- Brake light switch inoperative