Why Does the Brake Light Come On and How to Fix It?

A good braking system is one of the most important parts of a car.

Our safety depends on the braking system.

So, car manufacturers put brake sensors to let us know when the braking system is failing or if it is okay.

Sometimes, the brake sensor fails and shows a false warning, but most of the time, it shows the proper warning.

Let’s discuss what causes the brake lights to come on and possible solutions.

Why Does the Brake Light Come On?

There are five reasons why the brake warning light may come on, including low brake fluid, a parking brake that is engaged, a faulty ABS sensor, and a faulty brake sensor.

01. Low Brake Fluid

Low Brake Fluid

The most common reason brake warning lights come on is low brake fluid.

Brake fluid runs through the master cylinder, where a fluid level sensor is situated.

The brake system warning light on the dashboard turns on when the fluid level drops below the required level.

A brake system must have the right amount of fluid to function properly.

A low brake fluid level is also a sign of worn brake pads.

A leak in the cylinder sometimes causes low brake fluid levels.

Therefore, you should always check the fluid level, especially when your dashboard illuminates the brake system warning light.

How to Fix

Add fluid when the fluid level is low.

To turn off the brake warning light, repair or replace the worn cylinder if it leaks.

02. Engaged Parking Brake

Engaged Parking Brake

Most cars have a sensor that detects whether the parking brake is on.

Even if the parking brake doesn’t appear engaged, the brake light will illuminate if the sensors fail.

Parking brakes can overheat, resulting in brake damage.

If you drive with the parking brake on, the brakes can overheat, wear out the brake pads, or brake fluid leaks.

How to Fix

The brake warning lights will turn off when you pull the parking brake from park mode at the time of driving.

03. Wrong Brake Pads

Wrong Brake Pads

Wrong brake pads cause brake system warning lights to appear on the dashboard.

The wrong brake pads can lead to an expensive repair if you drive with them for too long.

Replacing the brake pads would be prudent to resolve the problem.

How to Fix

If you have installed the wrong brake pads, you should replace them with the correct ones.

04. Faulty ABS Sensor

Faulty ABS Sensor

Anti-lock Braking System (ABS) sensor failure causes the warning light to illuminate on the dashboard.

Diagnose and replace the ABS sensor to fix the problem.

How to Fix

The brake light will automatically go away when the faulty ABS sensor is replaced.

05. Faulty Sensor

Faulty Sensor

In most cases, a faulty sensor is the only problem.

When the sensor fails, it produces false codes, and the ECU (Electronic Control Module) activates the brake system warning light.

Here’s a video that may help you understand why your service brake system comes on.

How to Fix

Find out which braking sensor is faulty and replace it as soon as possible to turn off the brake warning light.


Metallic debris, dirt, or brake dust can lead to failing brake sensors.

Therefore, you should inspect the sensors when you see the service brake system light.

It’s wise to take the vehicle to a shop because they have the tools to find out what’s wrong.

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