What your brake warning light could mean and how to put things right

When you see a warning light illuminate on your dashboard console, it’s an alert that part of your car isn’t working correctly. You would like to think that this warning would trigger a direct response with all drivers, concerned with their safety and that of their passengers.

However, far too often, many of us keep driving as though nothing’s wrong. We assume that it’s a minor issue that can be resolved in time—with a complete disregard for their safety, and that of other road users.

Different colours dictate different levels of severity

One of the reasons we might ignore a warning light is if we’re not put into an immediate state of panic.

Different manufacturers work with different warning light systems, symbols and colours. Check your manual to be sure which relates to your car. That way, you’ll be readily informed for when the worst happens.

  • Red
  • Amber
  • Blue
  • White
  • Green

You may or may not have witnessed the full array of possible warning light colours, but you will have seen the most common.

Red warning lights

Red lights dictate the most severe issues. A red light means that there’s a significant problem NOW and needs immediate attention. A computer-controlled warning system may flash up precisely what the problem is and how you should react to it.

Amber warning lights

An amber warning light is there to let you know that something isn’t right, but your car should be safe to drive a short distance to get you home or to your mechanic.

What does it mean when the brake light comes on?

Okay, so back to that brake warning light on your car.

There are a handful of possible reasons for a brake system light to illuminate:

  1. Brake fluid warning light
  2. Handbrake warning light
  3. One or both of the brake lights isn’t working
  4. Worn or damaged brake pads
  5. ABS sensor warning (anti-lock brakes)
  6. Low voltage battery causing brake light issues

1. The brake fluid light

One of the most common faults with our cars’ brakes is when a car is low on brake fluid.

What does low brake fluid mean, and why would it happen?

Your brake fluid is stored in a reservoir, usually found under the bonnet on the driver’s side of the car. There will be a maximum and minimum level that your fluid should sit happily between.

If your brakes aren’t working efficiently, your brake fluid could be too low, there could air bubbles in the system, or it has become contaminated. Any of these suggest that it could be time for a top-up or a complete replacement.

Leaky brakes

There could be a leak in one of the fluid hoses or with the brake callipers. First, check your brake fluid level. If it’s dropped, check under the car for puddles or drips. Chase the line from the brake fluid reservoir to each wheel.

Brake pad and disc wear

Where the brake pads and discs have worn severely, they have to travel further to apply the correct braking pressure. This requires more brake fluid to cover the extra distance, which may result in a lower level of fluid in your reservoir.

Brake fluid sensor

If everything looks okay with every aspect of your brake system, and you’re still left scratching your head, it could be a simple sensor failure.

The sensors in our cars are often quite sensitive and prone to damage or failure. A simple brake fluid level sensor test should determine if this is your problem.

2. The handbrake light keeps coming on

Most cars will have a separate light for the handbrake or parking brake.

When illuminated, the first thing to check is that the handbrake is fully released and none of the brakes are sticking.

With a manual handbrake, check it is properly released and push the lever right down to the floor. For electronic parking brakes that operate with a button, check you’ve released them correctly. If your electronic brake release is automatic and it doesn’t release when you set off—well, it’s time to get in touch with your mechanic.

Why does my handbrake light keep coming on?

  • If your handbrake intermittently illuminates, it could be right on the edge of its limit, and the sensor is flicking between on and off.
  • It could be that you’re low on brake fluid, especially if the light flickers when driving around corners.
  • It could also be a dodgy sensor.

Whichever case, if you can’t tighten up the handbrake yourself, or top up the fluids, have your mechanic give your brake system the once over.

3. A brake light bulb is out

This is a simple problem to detect and fix. Checking your brake lights is as simple as taking a look at the rear of your car while someone operates the brake pedal.

Some bulbs are easier to access than others. If you feel comfortable replacing a blown bulb yourself, it’s a relatively straightforward like-for-like repair. Otherwise, a garage or service centre will carry out the change for a minimal charge.

Brake lights and blown fuses

If a new bulb doesn’t fix the problem, or if both brake lights are out, then the problem could be a blown fuse. Check your owner’s manual to find out where your fuses are located and which one is responsible for the brake lights.

4. Worn or damaged brake pads

Some cars will have a separate light for brake pad wear. This warning light is a circle with dashed lines just outside it on either side.

Brake pads have their own sensors, and when the material is worn to around the last 15%, the warning light will illuminate to alert the driver that it’s time to change them.

Driving with worn brake pads can be dangerous. On top of that, it causes unnecessary damage to the discs. Worn pads won’t stop you as efficiently as a healthy set will, so when you see that warning light—don’t chance it—book in for a replacement straight away.

5. ABS sensors

All modern cars (and most older vehicles) are fitted with anti-lock brakes as standard. This system helps to prevent lock-ups and cars skidding out of control. They’re particularly useful in poor weather conditions where road grip is limited.

The ABS has its own control module, so when it registers any kind of problem or malfunction, the warning light will tell you so.

Have the problem scanned by a mechanic with the correct diagnostic tools. They will locate the issue—whether it’s a faulty part or electrical problem—and advise on its repa