Quick answer
If the ABS light stays on after startup or comes on while driving and remains active, the vehicle may fail its MOT.
ABS helps prevent wheel lock under heavy braking, especially in wet or slippery conditions.
Why the ABS light can fail MOT
Braking safety fault
ABS may not operate correctly in emergencies.
Stored fault code
The control unit has detected a problem.
Wheel speed sensor issue
A common ABS warning cause.
Damaged reluctor ring
Incorrect wheel speed readings.
Wiring fault
Broken or corroded sensor wiring.
ABS pump/module issue
Hydraulic or electronic module failure.
Common reasons the ABS light comes on
- 1Faulty wheel speed sensor
- 2Broken sensor wire
- 3Damaged ABS ring
- 4Low battery voltage
- 5ABS pump or control module fault
How to fix it before MOT
The system normally needs scanning for fault codes. This helps identify which wheel or component is causing the warning.
Simply clearing the light often does not solve the underlying issue.
Related warning light and MOT guides
Frequently asked questions
If it comes on then goes off?
That is usually the normal startup check.
Can I still drive?
Usually yes, but ABS assistance may be lost.
Will normal brakes still work?
Often yes, but anti-lock function may not.
Can a sensor cause it?
Yes, sensors are one of the most common causes.
Will it always fail MOT?
An active ABS warning light commonly causes failure.
Best next step?
Have the ABS system diagnosed before the test.