Features

Brake System Warning Light: What Does It Mean?

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Your car has many different warning messages that can pop up on the dashboard, one of which is the brake system warning light. There’s also a separate anti-lock brake (ABS) warning light, as well as a brake pad warning light.

All three warnings are important—and you’ll want to know what each of them means.

What Does the Brake System Warning Light Mean?

The brake system warning light can indicate one of two things:

  • The parking brake is engaged
  • The brake fluid level is low
brake warning light car icon
The brake system warning light can indicate one of two things: the parking brake is engaged, or brake fluid level is low.

In either scenario, the light is turned on by a switch somewhere in the brake system. When you engage the parking brake, the brake handle closes a switch that turns on the warning light. Similarly, when the brake fluid level gets low (or in some cases, the fluid pressure drops), a switch inside the hydraulic system closes, triggering the warning light.

What should you do if the brake system warning light illuminates on your car’s dashboard? First, make sure that the parking brake is disengaged.

After confirming that the parking brake is off, you’ll want to check the brake fluid level. Low brake fluid can indicate either worn brake pads or a leak in the hydraulic system. A brake fluid leak is a serious concern that can result in a reduction or complete loss of braking ability. You should not drive the vehicle until the problem is fixed.

What Does the Anti-Lock Brake System (ABS) Warning Light Mean?

Since 2004, all vehicles sold in the United States have been required to have anti-lock brakes (ABS). The technology modulates fluid pressure to the brakes to prevent wheel lockup during a panic stop.

A computer (often referred to as the ABS control module) monitors the ABS system. When the module detects a problem within the system, it turns on the ABS warning light and stores a diagnostic trouble code (DTC) in its memory.

Many different problems—ranging from a faulty wheel speed sensor to a bad ABS pump—can trigger the ABS warning light. So, you (or your mechanic) will need to do some troubleshooting to determine the root cause of the concern.

Most professionals use a scan tool or code reader to retrieve the DTCs that are stored in the ABS control module’s memory. The DTCs then serve as a starting point for the rest of the troubleshooting process.

abs warning light
The ABS system modulates fluid pressure to the brakes to prevent wheel lockup during a panic stop.

What Does the Brake Pad Warning Light Mean?

Certain late-model cars are equipped with brake pad sensors. When the pads become worn, the sensors trigger a warning on the dashboard. Sometimes, that warning is a light that looks like a circle with dashed lines around the perimeter. In other instances, it’s a message in the instrument cluster that says “brake pads worn” or something similar.

When this warning light turns on, it almost always means you need a new set of brake pads. If you have the know-how, you can install a set of replacement pads yourself. Otherwise, you can have a professional do the job for you.

brake pad monitoring warning light
When the brake pads become worn, the brake pad sensors trigger a warning on the dashboard.

Is It Safe to Drive With the Brake Warning Light On?

Because the brake system warning light can indicate a hydraulic system leak, it has the potential to be the most dangerous of the brake-related warnings. As was mentioned, a brake fluid leak can lead to a reduction or complete loss of braking ability.

The ABS and brake pad warning lights should also be addressed right away. Both indicate there’s something wrong with your brake system that could affect the overall safety of your vehicle.

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