Every modern car has numerous warning lights on the dashboard to alert the driver to potential problems. One of the most important lights is the brake warning light. This light is activated as soon as there is a problem with the vehicle’s braking system. Defects in the brake system are thus often detected before they become a danger. Find out now in our guide when the brake warning light is activated and what you can do as a driver.

How the brake warning light works

The brake warning light is integrated directly into the instrument cluster of every modern car. This red warning light usually shows an exclamation mark, but can also look different depending on the vehicle. If a problem occurs in the brake system, the vehicle electronics activate the warning light. Depending on the vehicle model, the brake warning light is supplemented by an ABS warning light, which reports problems with the ABS system.

A short flash of the brake warning light after switching on the ignition is normal and serves as a check. If the warning light lights up or flashes continuously while driving, there is usually a serious problem with the brakes. Drivers should then park the vehicle at the earliest opportunity and have the brake system checked.

Do not confuse: Brake warning light and brake pad warning light

Depending on the vehicle model, the dashboard not only has a brake warning light, but also a brake pad wear warning light. This light usually shows a circle with brake shoes stylised on the side. The light turns yellow or red when a brake pad is approaching the wear limit and the part needs to be replaced.

When the brake warning light comes on – these are the most common causes

When the brake warning light comes on, the question of the reason quickly arises. There are several possible causes for the brake light coming on. Some of the causes can be easily remedied by the driver, while for others it is better to take the car to a mechanic in the workshop.

Handbrake was not released

Probably the most common cause for the brake warning light to light up is due to drivers’ forgetfulness. If the car has been parked, the subsequent release of the handbrake is sometimes forgotten. In this case, the brake warning light also lights up while driving to remind the driver to release the brake.

Low brake fluid level

An equally common reason for the brake warning light to illuminate is a low brake fluid level. If the brake fluid level is too low, there may be a problem when braking. To ensure that full braking power is always available when stepping on the brake pedal, the fluid must be topped up.

Leak in the brake system

If the brake warning light comes on because of a low brake fluid level, the cause of the fluid loss must be sought. Often there is a defect in the brake lines, or a leak in the brake hoses or joints. In such a case, replacement of the defective parts by a mechanic in the workshop is necessary.

Worn brake pads

Another cause for the brake warning light to come on can be worn brake pads. When the driver presses the brake pedal, the brake pads are pressed onto the brake disc of each wheel. The brake pads wear out faster than the brake disc and the braking effect decreases. Depending on the vehicle model, the brake warning light then lights up.

Defect on the handbrake switch

If the brake system warning light does not go out even though the brake system is OK and the brakes are released, there may also be a defect in the handbrake switch. For example, the switch may be stuck and signal to the vehicle electronics that the handbrake is applied. Often, the only solution is to replace the defective part.

Instrument cluster is defective

In modern cars, the instrument cluster in the dashboard can also be responsible for the faulty illumination of warning lights. If there is a defect here, the information from the sensors and switches of the brake system is no longer processed correctly. If the brake light is then permanently lit, the instrument cluster should be replaced.

Sensors or cables damaged

Every modern car today has numerous sensors that monitor all components of the brake system and ABS system. If the sensors do not function properly or the cables are damaged, the ABS warning light or brake warning light can be activated. Sometimes corrosion on the plug contacts is also responsible for the problem.

The brake warning light is on – what drivers can do

As a driver, you should always pay special attention to the illumination of the brake warning light or the ABS warning light. You can take these simple steps yourself when the warning light comes on.

1. Stop the vehicle: If the warning light lights up or flashes while driving, the car should be stopped at the next safe opportunity. Defective brakes can otherwise quickly become a danger.
2. Check the handbrake: Most often the brake indicator light comes on because the handbrake has been forgotten. This can happen quickly – especially in vehicles without an electric handbrake. After releasing the brake the light should go out.
3. Check the brake fluid: Technically experienced drivers can check the brake fluid level when the warning light comes on. The corresponding container for the fluid is usually located in the engine compartment and is easily accessible.
4. Top up brake fluid: The level of fluid in the reservoir should be between maximum and minimum. If there is too little brake fluid in the brake fluid reservoir, it should be topped up.
5. Look for a leak in the brake system: If the brake fluid keeps dropping, there could be a leak within the brake system. To be on the safe side, all brake lines and brake hoses should be visually checked for defects.
6. Check brake pads: Worn brake pads can cause the brake fluid to drop and, depending on the vehicle model, the brake warning light to come on. With disc brakes, the pad thickness can be checked after removing the wheels.
7. Call for help: If there are problems with the brakes, professional help is needed. A mechanic from the workshop or an automobile club has all the information about the car. He can answer all questions and check the brake system. With car clubs, roadside assistance is already covered by the annual dues.

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