Why is my red brake warning light on when the handbrake is off?

Because the same lamp is wired to more than one switch. With the handbrake down, the two remaining candidates are the brake fluid level float in the reservoir and the braking control module. Check the fluid level against the MIN mark on the reservoir first — you can read it through the plastic without opening the cap. If the level is fine, the fault is electronic and needs the codes reading. A third possibility is that the handbrake switch itself has gone out of adjustment, which is common on cars where the lever has been pulled up hard for years.

Can I drive with the red brake warning light on?

Not until you know why it is on. If the handbrake is fully off and the fluid level is correct and the pedal feels exactly as it always has, the car is probably safe to drive gently to a garage. If the fluid is low, the pedal has gone long or spongy, or it sinks towards the floor while you hold steady pressure at a junction, stop and have it recovered. A hydraulic system losing fluid loses more of it every time the pedal is pressed.

Does a brake warning light fail an MOT?

Yes. A brake tell-tale showing a system malfunction is a major defect, and so is a warning device that does not light at all when it should. In the DVSA data behind this site, 85,196 MOT failures were recorded against this exact wording. The certificate says 'Warning device shows system malfunction' and nothing more specific, because DVSA uses identical wording for the anti-lock system and the electronic braking system, so it will not tell you which one the car was complaining about.

My MOT certificate says 'warning device shows system malfunction' — what does that mean?

It means a brake system warning lamp was lit, or was not working, when the tester checked it. The wording is deliberately generic: it is used for both the anti-lock braking system under section 1.6 of the inspection manual and the electronic braking system under 1.7, so the certificate does not identify which system reported the fault. The only way to find out is to have the braking control module scanned, which will name the circuit that logged the code.

What is the difference between the red brake light and the amber ABS light?

The amber ABS lamp means the anti-lock function has switched itself off — your brakes still work normally, they just will not modulate if a wheel locks. The red lamp means the braking system itself is reporting a problem, which could be fluid level, a hydraulic fault, or a loss of electronic brakeforce distribution. Amber on its own means get it looked at within days. Red, or red and amber together, means stop and check before you go any further.

Dashboard warning light

Brake warning light

Last updated 27 July 2026

Quick answer

With the handbrake fully off, a red brake lamp means the car is reporting a problem with the braking system itself — most often fluid that has dropped below the minimum mark, or a fault in the electronic side of the brakes. Treat it as a reason to stop and check rather than a reason to press on.

What to do: Stop as soon as it is safe
Can you drive?: No

Why it is red

Reserved for hazards and for faults where continuing could injure somebody or destroy something expensive. Most red lamps mean stop, though a few mean the opposite, so read the lamp rather than the colour.

What turns it on

The same red lamp is wired to several switches on most cars: the handbrake, a float in the brake fluid reservoir, and the braking control module. Any one of them can light it. Some cars also light the red lamp alongside the amber ABS lamp when the electronic brakeforce distribution function drops out, because that changes how hard the rear brakes work and is more serious than losing anti-lock alone.

What to do about it

Check the handbrake is fully released first. It is the same lamp on the majority of cars and it costs nothing to rule out.
If the handbrake is off and the lamp stays on, stop somewhere safe and press the pedal firmly. A pedal that feels normal and high is reassuring; one that feels long, spongy, or sinks slowly under steady pressure means the car should not be driven.
Look at the brake fluid reservoir under the bonnet. It is translucent and marked MIN and MAX, so you can read the level without opening it — and you should not open it unnecessarily, because brake fluid absorbs moisture from the air.
If the fluid is low, do not simply top it up and carry on. The fluid has gone somewhere: either the pads have worn down and the pistons have moved out to follow them, or there is a leak.
Look under the car and behind each wheel for wet patches. Brake fluid is thin, clear to light brown, and strips paint where it lands.
If the handbrake, pedal and fluid all check out, the fault is electronic and needs the codes reading before anything is replaced.

Can you keep driving?

Until you know which of the three switches lit the lamp, you do not know whether you have a stuck handbrake or a hydraulic leak, and those two are not close to each other in consequence. A brake system that is losing fluid gets worse every time you press the pedal. Check the handbrake and the fluid level at the roadside; if either is wrong, or the pedal feel has changed at all, have the car recovered rather than driven.

What causes it

The handbrake not fully released, or a misadjusted handbrake switch
Brake fluid below the minimum mark, usually from worn pads or a leak
A leaking brake pipe, flexible hose, calliper or master cylinder
An anti-lock or electronic braking system fault serious enough to affect brakeforce distribution
A failed float switch in the fluid reservoir, which lights the lamp with the level perfectly normal
On cars with an electronic parking brake, a fault in the parking brake actuator

Does it fail an MOT?

Yes. A tester records it as a major defect, under the wording Warning device shows system malfunction in the MOT inspection manual (section 1.6 for anti-lock braking, 1.7 for the electronic braking system).

Vehicles fitted with anti-lock braking or an electronically controlled braking system. The tester also fails a car whose warning device does not work at all, because a lamp that cannot light cannot report a fault.

It is not a technicality either. Across the DVSA test data behind this site, 85,196 MOTs were failed on it, spread across 365 different models.

Models where it happens most

Share of all tests on that model where this defect was recorded, among models with at least 20,000 tests. Compared against 0.60% across every model that records it.

Peugeot 3071.95%
422 of 21,622 tests
Volvo V401.68%
1,635 of 97,266 tests
Honda Accord1.66%
380 of 22,892 tests
Volkswagen Transporter1.53%
4,899 of 320,448 tests
Peugeot 2061.36%
466 of 34,316 tests
Volvo V701.21%
459 of 37,984 tests
Vauxhall Vivaro1.18%
2,145 of 182,252 tests
Volkswagen Scirocco1.16%
530 of 45,864 tests

A high rate is not proof a model is badly built. Fleet age, annual mileage and how a model is used all move these figures, and vans and commercial derivatives sit near the top of most emissions defects for that reason rather than through poor engineering.

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.

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

Common questions

Why is my red brake warning light on when the handbrake is off?: Because the same lamp is wired to more than one switch. With the handbrake down, the two remaining candidates are the brake fluid level float in the reservoir and the braking control module. Check the fluid level against the MIN mark on the reservoir first — you can read it through the plastic without opening the cap. If the level is fine, the fault is electronic and needs the codes reading. A third possibility is that the handbrake switch itself has gone out of adjustment, which is common on cars where the lever has been pulled up hard for years.
Can I drive with the red brake warning light on?: Not until you know why it is on. If the handbrake is fully off and the fluid level is correct and the pedal feels exactly as it always has, the car is probably safe to drive gently to a garage. If the fluid is low, the pedal has gone long or spongy, or it sinks towards the floor while you hold steady pressure at a junction, stop and have it recovered. A hydraulic system losing fluid loses more of it every time the pedal is pressed.
Does a brake warning light fail an MOT?: Yes. A brake tell-tale showing a system malfunction is a major defect, and so is a warning device that does not light at all when it should. In the DVSA data behind this site, 85,196 MOT failures were recorded against this exact wording. The certificate says 'Warning device shows system malfunction' and nothing more specific, because DVSA uses identical wording for the anti-lock system and the electronic braking system, so it will not tell you which one the car was complaining about.
My MOT certificate says 'warning device shows system malfunction' — what does that mean?: It means a brake system warning lamp was lit, or was not working, when the tester checked it. The wording is deliberately generic: it is used for both the anti-lock braking system under section 1.6 of the inspection manual and the electronic braking system under 1.7, so the certificate does not identify which system reported the fault. The only way to find out is to have the braking control module scanned, which will name the circuit that logged the code.
What is the difference between the red brake light and the amber ABS light?: The amber ABS lamp means the anti-lock function has switched itself off — your brakes still work normally, they just will not modulate if a wheel locks. The red lamp means the braking system itself is reporting a problem, which could be fluid level, a hydraulic fault, or a loss of electronic brakeforce distribution. Amber on its own means get it looked at within days. Red, or red and amber together, means stop and check before you go any further.

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.

Check what your car has actually failed on

Free MOT history for any UK registration, straight from DVSA records.