Seeing the brake light on the dashboard suddenly light up bright red—and your parking brake isn’t engaged—can be alarming. But there’s no need to panic. You simply need to find out what the light is warning you about and what you must do when it does come on—which is probably what you’re doing now.
This guide provides an overview of the brake warning light, what causes it, and what you can do to turn it off.
What Causes a Brake Warning Light to Turn On?
The brake warning light is a safety feature that alerts you to a potential issue with your vehicle’s brakes. It typically appears on most dashboards as a bright red or orange circle with an exclamation point in the middle, although some vehicles may have a slightly altered design.
Many different reasons can trigger the brake warning light. Some of the most common causes include:
Parking Brake is Engaged
Let’s start with the most obvious one: the number one reason for the brake light to turn on is an activated parking brake. The parking brake sensor automatically switches the brake light on when the parking brake is engaged, which helps remind drivers to disengage the brake before driving off.
Worn-Out Brake Pads
If the brake pads are severely worn, the brake sensor wire will start to come into contact with the rotor and cause the brake warning light to switch on. But most vehicles aren’t equipped with this feature, so don’t count on the red brake light to tell you when your pads are worn enough to require replacement.
Extremely worn brake pads can also force the caliper pistons to extend past their seals and leak enough fluid to change the pressure in that brake circuit. This will cause the proportioning valve switch to illuminate the brake warning light.
Low Brake Fluid
There’s a sensor in the brake master cylinder that constantly monitors the brake fluid level. Once it drops to critical levels, the sensor triggers the brake warning light.
As the brake pads wear, more of the system fluid resides in the calipers rather than in the reservoir, and the fluid level is expected to lower in the master cylinder reservoir for this reason.
An early warning sign that your brake fluid is getting low is when your instrument panel brake warning light remains illuminated until the engine compartment warms enough to expand the fluid slightly so that the brake light goes out. If you’re seeing this every morning, check the brake fluid level.
Sensor Failure
Modern automotive braking systems include an array of sensors that monitor its performance. Should any of these sensors malfunction, it will automatically cause the brake light to turn on. The proportioning valve switch illuminates the red brake light when the brake circuit pressures are out of balance due to a fluid leak. If the switch isn’t working right or if the ABS solenoid pack in Rear Anti-Lock Braking systems is unplugged or has bad wiring, the red light will come on.
ABS Malfunction
An illuminated brake warning light can also mean that one of the Anti-Lock Braking System (ABS) components is malfunctioning. Some vehicles might also have a standalone warning light that turns on during an ABS failure, but the red brake light still usually comes on along with the ABS light in situations like this.
How to Turn Off the Brake Warning Light on Your Dashboard
If the brake warning light comes on while driving, pull over as soon as you get to a safe spot—not a bad neighborhood or a place where the vehicle might get hit by a passing car. Once you’ve parked the car at a safe location, here are some steps you can take to resolve the issue:
If the parking brake is engaged, or if the brake pedal doesn’t fully return to its released position (this happens on older cars with a park brake pedal), then put your foot under the pedal and gently pull it upward while watching the brake warning light. If it goes off, you have a weak pedal return spring or a sticking pedal.
Check the Brake Fluid Level
Check if the brake fluid is at recommended levels—always do this first after making sure the parking brake is completely disengaged.
When you’re able to, refill the brake fluid or drive to a shop that can do it for you. If fluid levels continue to drop, it might be a sign of a leak in the system.
Replace Brake Pads (If Worn Out)
Change the brake pads if they appear to be worn beyond their limit. In case of extreme wear, checking if the brake rotors are damaged and need replacing is recommended.
If the brake warning light persists even after all these steps or the brakes appear in working condition, have the vehicle inspected by a qualified mechanic for a professional diagnosis.
FAQ
Can you drive with the brake light on?
It depends on why you have an illuminated brake warning light. If the brakes feel normal, you can drive until you know it’s safe to stop before checking to see if you can find the problem. If the vehicle has to be driven to a repair shop, it must be done cautiously and at careful speeds to avoid accidents.
How long can you drive with your brake light on?
There is no limit to how long you can drive a vehicle with the brake light on, but it is not advisable to do so, especially for extended periods. An illuminated brake warning light can indicate that the vehicle’s brakes are not functioning properly and may pose a safety risk to you and others on the road.