Does an ABS light fail an MOT?

Yes. An anti-lock braking warning lamp indicating a malfunction is a major defect, and a car cannot pass with it lit. A lamp that never lights at all is also a failure, because a tester has no way to tell whether the system is healthy. The one thing that catches people out is the wording on the certificate: DVSA records it as 'Warning device shows system malfunction' rather than naming ABS, because the same wording covers the electronic braking system.

Is it safe to drive with the ABS light on?

Your brakes still work. Pressing the pedal slows the car exactly as it did before, and nothing about normal driving changes. What you have lost is anti-lock intervention, so in an emergency stop — particularly on a wet or loose surface — a wheel can lock, and a locked front wheel means the car will not steer while it is locked. Leave more room, brake earlier, and get it fixed within days rather than months.

Why did my ABS light come on after changing the battery?

The ABS module is sensitive to supply voltage, and a flat battery, a jump start or the momentary drop while a battery is swapped can be enough to set a fault code and latch the lamp on. Quite often the underlying system is fine and the code simply needs clearing with a scan tool once the battery is healthy — the lamp will not clear itself. If it returns after clearing, there is a real fault to find.

Can I just remove the ABS to get rid of the light?

No. On a car first used on or after 1 January 2010 it is not permissible to remove or disable the ABS at all, and a tester who sees the system has obviously been removed will fail the car. On an older car where removal is allowed, the whole system has to come out rather than just being disconnected, and a half-removed system with a lamp still lit fails anyway.

Why are my ABS and traction control lights on together?

Because they share hardware. Stability and traction control both work by reading the same four wheel speed sensors and using the ABS pump and valves to brake individual wheels. Lose a wheel speed sensor and both systems go down at once, which is why the lamps almost always appear as a pair. Fixing the ABS fault normally clears both.

Dashboard warning light

ABS warning light

Last updated 27 July 2026

Quick answer

The anti-lock braking system has found a fault and switched itself off. Your brakes still work exactly as they always did in normal driving — what you have lost is the system that stops the wheels locking and the steering going light under a hard, emergency stop.

What to do: Get it checked within days
Can you drive?: Briefly, gently

Why it is amber

A system has reported a malfunction, or something needs attention. The car is usually still driveable, but the fault will not clear itself and several amber lamps are an automatic MOT failure.

What turns it on

A sensor at each wheel reports its speed to the ABS module many times a second. If one signal disappears, reads implausibly against the other three, or the module cannot power its pump or valves, the system shuts itself down rather than risk intervening on bad data, and lights the lamp to tell you it has stood down.

What to do about it

Carry on driving, but leave more room. Ordinary braking is unaffected; what has gone is your margin in an emergency stop, and that margin is largest in the wet.
Avoid stamping on the pedal in the meantime. Without ABS a panic stop can lock a wheel, and a locked front wheel means no steering.
Get the codes read. An ABS fault is almost always traced to one named wheel, and knowing which one turns a diagnostic job into a specific repair.
Check whether the stability control lamp came on at the same time. Stability control depends on the same wheel speed sensors, so the two usually fail together — and that combination is two MOT defects, not one.
If the lamp appeared straight after a battery change, a jump start or a long period standing, have the battery and charging system checked before assuming the ABS is at fault. Low system voltage sets these codes readily.
Book it in before the MOT. The lamp is a major defect and the car cannot pass with it lit.

Can you keep driving?

Briefly, gently

Yes, with a clear caveat. Normal braking is untouched and the car behaves as it always has right up to the point where a wheel locks — which is the point ABS exists for. Drive it to a garage, leave extra distance, and be aware that stability control has almost certainly gone with it, so the car will not catch a slide either. It will not pass an MOT in this state.

What causes it

A failed or contaminated wheel speed sensor, comfortably the most common cause
A corroded or damaged reluctor ring, the toothed ring the sensor reads, which on many cars is built into the wheel bearing
Wiring chafed or broken where the loom flexes with the suspension, usually behind a front wheel
Low battery or charging system voltage, which the module reads as a fault
A failed ABS pump motor or valve block
A blown fuse, or corrosion in the module's connector

Does it fail an MOT?

Not on its own — but what causes it often does.

An illuminated ABS lamp is a major defect and will fail the test — but it is not recorded under a defect that names ABS. DVSA logs it as 'Warning device shows system malfunction', wording shared word for word with the electronic braking system, so the certificate rarely identifies which system was at fault. A lamp that does not light at all when the ignition is switched on is also a failure, because it cannot then report anything. Separately, a car first used on or after 1 January 2010 fails if the ABS has obviously been removed.

Fault codes that turn this light on

The lamp tells you which system reported a problem. The code stored behind it names the check that failed, which is the difference between knowing something is wrong and knowing where to look. These are the ones that commonly sit behind this symbol.

C0035 Front left wheel speed sensor not reading
C0040Right Front Wheel Speed Sensor Circuit Malfunction
C0045 Rear left wheel speed sensor not reading
C0050Right Rear Wheel Speed Sensor Circuit Malfunction
C0110 ABS pump motor not running
U0121 No communication with the ABS module

Got a different code? Look it up — the index covers every standard OBD-II code.

Common questions

Does an ABS light fail an MOT?: Yes. An anti-lock braking warning lamp indicating a malfunction is a major defect, and a car cannot pass with it lit. A lamp that never lights at all is also a failure, because a tester has no way to tell whether the system is healthy. The one thing that catches people out is the wording on the certificate: DVSA records it as 'Warning device shows system malfunction' rather than naming ABS, because the same wording covers the electronic braking system.
Is it safe to drive with the ABS light on?: Your brakes still work. Pressing the pedal slows the car exactly as it did before, and nothing about normal driving changes. What you have lost is anti-lock intervention, so in an emergency stop — particularly on a wet or loose surface — a wheel can lock, and a locked front wheel means the car will not steer while it is locked. Leave more room, brake earlier, and get it fixed within days rather than months.
Why did my ABS light come on after changing the battery?: The ABS module is sensitive to supply voltage, and a flat battery, a jump start or the momentary drop while a battery is swapped can be enough to set a fault code and latch the lamp on. Quite often the underlying system is fine and the code simply needs clearing with a scan tool once the battery is healthy — the lamp will not clear itself. If it returns after clearing, there is a real fault to find.
Can I just remove the ABS to get rid of the light?: No. On a car first used on or after 1 January 2010 it is not permissible to remove or disable the ABS at all, and a tester who sees the system has obviously been removed will fail the car. On an older car where removal is allowed, the whole system has to come out rather than just being disconnected, and a half-removed system with a lamp still lit fails anyway.
Why are my ABS and traction control lights on together?: Because they share hardware. Stability and traction control both work by reading the same four wheel speed sensors and using the ABS pump and valves to brake individual wheels. Lose a wheel speed sensor and both systems go down at once, which is why the lamps almost always appear as a pair. Fixing the ABS fault normally clears both.

This is general guidance, not a diagnosis. Manufacturers draw the same system differently and reuse symbols for more than one function, so check the handbook for your own car before acting on anything here.

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