Is an ABS warning light an MOT failure?

Yes, where ABS is fitted it is a testable item, and a lamp indicating a system malfunction is a major defect. Missing or obviously damaged ABS components and damaged wiring are also major defects. The test relies on the vehicle's own self-diagnosis rather than checking that the system modulates the brakes, which is why the state of the lamp matters so much.

Can I drive with the ABS light on?

Ordinary braking still works, so the car feels normal, but you have lost the system that stops the wheels locking. Brake hard on a wet or loose surface and the wheels lock, the tyres stop gripping sideways and you cannot steer around whatever you were braking for. Traction and stability control usually go down with it, since they share the same sensors.

What usually causes an ABS warning light?

A failed or contaminated wheel speed sensor, by a wide margin. After that come a damaged sensor cable where it flexes with the suspension, a corroded connector behind the wheel arch liner, or a rusted reluctor ring sending a broken signal from an otherwise healthy wheel. A failing pump or control module is much rarer and far more expensive.

Will taking the ABS bulb out get the car through the MOT?

No, and it makes matters worse. A warning lamp that does not work at all is itself a major defect, because the tester cannot confirm the system is healthy and treats a dead lamp exactly as a fault. Removing the bulb or disabling the circuit fails the car just as reliably as the original problem would have.

How much does it cost to fix an ABS fault?

Diagnostics are £40 to £80 and worth paying for, because guessing here is expensive. A wheel speed sensor is £20 to £60 as a part and £90 to £180 fitted, more if the old one has to be drilled out of the hub. A reluctor ring built into a wheel bearing means £200 to £350, and pumps or modules start at £250 for the part alone.

MOT defect file

ABS warning lamp indicates a fault

Last updated 27 July 2026

Quick answer

The anti-lock braking warning light is on, or it will not light at all when it should. Ordinary braking still works, but the system that stops the wheels locking under heavy braking is not available.

Typical cost: £90–£500
DIY viability: Garage job

A testable malfunction indicator that stays illuminated with the engine running records a system fault. The exact symbol varies by vehicle, but ABS, SRS, electronic power steering, ESC, engine management, brake-system and tyre-pressure warnings must not be ignored.

What you might notice

An amber ABS lamp that stays lit after the ignition self-check instead of going out
The lamp coming on only after a few minutes of driving, or only when turning one particular way
No pulsing or chattering from the pedal in an emergency stop, where the wheels simply lock instead
On many cars the traction control or stability control light comes on at the same time, because they share the same wheel speed sensors

What causes it

A failed or contaminated wheel speed sensor, by a wide margin the most common cause
A damaged sensor cable where it flexes with the suspension, or a corroded connector behind the wheel arch liner
A rusted or chipped reluctor ring, so the sensor reads a broken signal from an otherwise healthy wheel
A failing ABS pump or control module, which is much rarer but far more expensive

Advisory or failure?

Where ABS is fitted, it is a testable item, and a warning lamp indicating a system malfunction is a major defect and a failure. A warning lamp that does not work at all is equally a major defect — if the bulb has been removed or the circuit disabled, the tester cannot confirm the system is healthy and treats that the same as a fault. Missing or obviously damaged ABS components, or damaged wiring, are also major defects. What the test does not do is check that the system actually modulates the brakes in an emergency stop; it relies on the vehicle's own self-diagnosis, which is why the state of the lamp matters so much.

Can you fix it yourself?

Garage job

Reading the fault code is the whole job, and guessing without one is expensive. A cheap generic code reader often shows engine codes only, so this needs a tool that talks to the ABS module specifically. That said, once a code points at one wheel speed sensor, replacing it is frequently a single bolt and a connector, and well within DIY reach — the sensor is £20 to £60 and the usual difficulty is that the bolt has corroded into the hub. Clear the code afterwards and confirm the lamp stays out on a road test. Two traps: a code stored against a sensor is often actually a damaged cable or a rusty reluctor ring, so inspect before you buy, and on some cars replacing the module requires it to be coded to the vehicle.

What it costs

Diagnostics are £40 to £80 and worth paying for. A wheel speed sensor is £20 to £60 as a part, fitted for £90 to £180 depending on whether the old one has to be drilled out of the hub. A reluctor ring built into a wheel bearing means replacing the bearing, which is £200 to £350. The top of the band is the ABS pump or control module: parts are £250 upwards, and either the unit has to be coded to the car or the original circuit board repaired by a specialist. Given that spread, resist any quote for a pump before a sensor has been ruled out.

What happens if you ignore it

With ABS disabled you keep normal braking, so the car feels fine and the fault is easy to live with. The difference only appears in the moment you brake hard on a wet or loose surface: the wheels lock, the tyres stop gripping sideways, and you lose the ability to steer around whatever you were braking for. Stopping distances on a poor surface lengthen considerably. Because most cars share wheel speed data across systems, an ABS fault commonly disables traction and stability control too, and on newer cars it can also take out hill-hold and autonomous emergency braking. It is also an MOT failure that will not clear itself, so it has to be dealt with before the car can be used on the road.

Common questions

Is an ABS warning light an MOT failure?: Yes, where ABS is fitted it is a testable item, and a lamp indicating a system malfunction is a major defect. Missing or obviously damaged ABS components and damaged wiring are also major defects. The test relies on the vehicle's own self-diagnosis rather than checking that the system modulates the brakes, which is why the state of the lamp matters so much.
Can I drive with the ABS light on?: Ordinary braking still works, so the car feels normal, but you have lost the system that stops the wheels locking. Brake hard on a wet or loose surface and the wheels lock, the tyres stop gripping sideways and you cannot steer around whatever you were braking for. Traction and stability control usually go down with it, since they share the same sensors.
What usually causes an ABS warning light?: A failed or contaminated wheel speed sensor, by a wide margin. After that come a damaged sensor cable where it flexes with the suspension, a corroded connector behind the wheel arch liner, or a rusted reluctor ring sending a broken signal from an otherwise healthy wheel. A failing pump or control module is much rarer and far more expensive.
Will taking the ABS bulb out get the car through the MOT?: No, and it makes matters worse. A warning lamp that does not work at all is itself a major defect, because the tester cannot confirm the system is healthy and treats a dead lamp exactly as a fault. Removing the bulb or disabling the circuit fails the car just as reliably as the original problem would have.
How much does it cost to fix an ABS fault?: Diagnostics are £40 to £80 and worth paying for, because guessing here is expensive. A wheel speed sensor is £20 to £60 as a part and £90 to £180 fitted, more if the old one has to be drilled out of the hub. A reluctor ring built into a wheel bearing means £200 to £350, and pumps or modules start at £250 for the part alone.

Warning lights behind this

This defect is what a tester writes down. What you see from the driver’s seat is a symbol, and it is worth checking which one, because manufacturers reuse the same shape for more than one system.

Fault codes behind this failure

A failure certificate records that the lamp was lit, not what lit it. If this is what your certificate says, one of these codes is usually stored behind it, and reading it is the difference between a diagnosis and a guess.

Look up any of the other 4, or search the full index by code or symptom.

This is general guidance, not a diagnosis. The severity DVSA records depends on the specific fault found, so the same item can appear as an advisory on one test and a failure on another. Ask a qualified tester or mechanic to inspect the vehicle.

Has this been recorded on your car?

Check the full MOT history for any UK registration.