Why Is My Brake Light On? – Common Causes & How To Fix It

When you’re talking about brake lights staying on, there are two potential areas. The first is the dashboard brake light, and the second is the brake lights on the back of your vehicle.

If either light stays on all the time, it’s a problem. Unlike many guides, we addressed both problems for you here. That way no matter the cause you can answer the question of why my brake light is on. Not only will we give common causes for both problems, but we came up with a troubleshooting guide for both issues too.

6 Reasons My Brake Light Is on My Dashboard

If the problem you’re experiencing is a brake light on your dashboard, then your vehicle is trying to tell you something. But unless you know what it means you might miss the message entirely! Below we’ve highlighted six different reasons the brake light might be on your dashboard.

1. Park Brake Is On

This is by far the most common reason there’s a brake light on your dashboard. It’s a normal feature to help keep you from driving around with the parking brake engaged, which is a pretty useful feature.

Sometimes all you need to do to get the light off is to take off the parking brake. Also, check that it’s fully disengaged. One of the easiest ways to do this is to simply reapply the parking brake and then disengage it again.

2. Broken Park Brake Sensor

The dashboard knows if you applied the parking brake by a sensor. On parking brakes with a foot pedal, the sensor is typically behind the pedal, and those with a hand brake or a push-button parking brake have the sensor somewhere in the electrical circuit.

While these sensors typically last a long time, occasionally they will fail. When that happens the system defaults to a position where it thinks the parking brake is on, and you won’t be able to get it off until you replace the sensor.

3. Broken Brake Light Bulb

Some vehicles come with a sensor that lets you know that your brake lights need some attention. The most common problem a brake system goes through is a burnt-out bulb, and some vehicles have a nifty feature to let you know when this happens.

It’s a pretty great feature since you can’t see your own brake lights which makes it a challenge to know when one goes out. Even better, if you’re willing and able to replace the brake light bulb yourself you can likely fix the problem for just a few dollars.

4. Low Brake Fluid

If your vehicle is low on brake fluid you should get a light on the dash, which is a serious problem. That’s because the brake fluid system is a sealed system, so if you’re low on brake fluid you have a leak somewhere.

Moreover, the brake system works through hydraulic pressure, and without a sealed system full of brake fluid you can lose all braking power. A small brake fluid leak will create serious problems when you’re trying to stop, and large leaks can cause the brakes to fail completely.

5. Worn Brake Pads

Not only do some vehicles have a system that lets you know when a brake light goes out, but some vehicles have a feature that turns the light on when it’s time to swap out the brake pads.

Older vehicles rely on “squeakers” to let you know when it’s time to replace the brakes, but if you don’t hear the squeak, you won’t know when it’s time to replace them. Vehicles with the advanced sensors actively track how much life is on the brake pads and sends you a sign you can’t miss with the dashboard light.

Related: 10 Reasons Why Your Brakes Are Squeaking – & How to Fix It

6. ABS Brake Problem

Often your vehicle will have an ABS-specific light on the dashboard to let you know that’s the system that’s acting up, but if your vehicle has ABS but not an ABS-specific light, the regular brake light might turn on if there’s a problem.

There are tons of sensors throughout the ABS, and if any of these sensors start acting up the light should turn on. Keep in mind that if the light is on for an ABS problem, your vehicle can no longer use the ABS brakes. They won’t turn on when they shouldn’t, but if you need them, you won’t have them.

Related: ABS and Traction Control Light On – Meaning, Causes & Reset

5 Reasons My Brake Light Is On Behind My Vehicle

If you came here looking for advice on how to get the brake light on your vehicle off, this section is for you. We’ve highlighted the five most common reasons this might happen on your vehicle for you here.

1. Faulty Brake Light Switch

This is a problem that we highlighted because you might have a brake light on your dashboard, but it’s something that might keep the brake lights on too. The brake light switch is what tells the vehicle that you’re depressing the brake pedal and to turn on the brake lights.

When everything is working as it should then it’s a pretty effective system. But if the switch stops working you can either lose the ability to turn on the lights at all, or you might find that they’re always on.

2. Faulty Brake Light Bulb

Many brake lights use a dual filament bulb with one light always on for running lights. It’s a great system that gives you both running lights and brake lights for added safety, but if the bulb shorts out both lights might always stay on.

This is a problem you should consider if just one of the brake lights always stays on.

3. Broken Brake Light Socket

Another potential problem you should consider if just one brake light always stays on is a broken brake light socket. A broken socket can divert power to the wrong area, resulting in a brake light that always stays on.

It can also short out the system, blow a fuse, and lead to a system where none of the brake lights on your vehicle work.

4. Stuck Brake Pedal

If you can’t fully release the brake pedal then of course you’re always going to have a brake light on! Not only that, but you’re going to wear out the brake pads faster than you should, and you might even cause them to glaze over and lose braking power.

Some WD-40 might be all you need to fix the problem, or you might need to replace a few components to get everything working as it should again.

5. Electrical Problems

Electrical problems can create all sorts of issues for your vehicle. An electrical problem that only causes a brake light to stay on is possible, but it’s not the most likely explanation. The most likely reason for an electrical problem to do this would be a short that sends power to the same line that turns on the brake light.

But if that short were to send power just about anywhere else it would likely blow a fuse or lead to further problems for other components.

Troubleshooting a Dashboard Brake Light

If you’re troubleshooting a dashboard brake light start by connecting a scan tool and seeing what the code says. Car part stores like AutoZone will typically read the code for you for free if you don’t have your own scan tool.

This code will point you in the right direction and will practically tell you exactly what problem on our list is going on with your vehicle. But before you drive your vehicle to a parts store, double-check the brake fluid level and do yourself a favor and see if both brake lights turn on.

While the code reader would tell you both these things, it might save you a trip and you won’t have to drive your vehicle with a potentially unsafe brake fluid leak.

Troubleshooting a Brake Light Behind My Vehicle

If you have a brake light that won’t turn off on your vehicle there’s no scan tool that you can hook up that will automatically tell you what’s going on.

The first thing you need to figure out is if both brake lights won’t turn off or just one. If both lights won’t turn off the problem is likely a faulty brake light switch, a stuck brake pedal, or another electrical problem.

Try manually lifting the brake pedal to see if the lights turn off, if not try disconnecting the brake light switch. If disconnecting the switch turns off the light, the problem is likely the switch itself. However, if the light stays on then the problem is a more complex electrical problem that you’ll need to troubleshoot.

But, if only one brake light stays on, then you should start by checking the bulb. While you can swap the bulb with the other side, we recommend getting a new bulb. This will rule out a situation where you have two problems, like a defective bulb and a brake light system that won’t shut off.

From there, take a good look at the socket for potential problems, and keep in mind the problem might be something else in the electrical system.

Final Thoughts

Now that you know a little more about why is my brake light on, all that’s left is for you to head out and start troubleshooting it yourself. Whatever you do, don’t just ignore the problem because it can be a serious safety issue.

If you can’t figure it out yourself, go ahead and take your vehicle to a certified mechanic so they can troubleshoot the problem and tell you exactly what’s going on before a serious safety issue comes up.

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