5 Causes of an ABS Light to Come On (and What to Do)

(Updated on April 19, 2022)

Modern vehicles have what is known as an anti-lock braking system. The purpose of this system is to keep the driver safe by preventing the wheels from locking up as you apply the brakes. That way, you can keep control over the steering and your vehicle won’t skid as a result of the wheels locking up.

In addition, there is a warning light on the dashboard which will illuminate if there is any sort of problem with the anti-lock braking system. This is a light that you need to take seriously because it is an early warning sign that your braking system needs to be inspected right away.

What Does ABS Mean?

“ABS” stands for anti-lock braking system. When you step on the brakes hard, you are likely to lose traction on one or more tires. This is called lock-up. Tire lock-up happens when the friction between the brake pad and the brake rotor is greater than the friction between the tire and the road surface.

When your tires are spinning, you have better control over the car. You will also typically experience a shorter stopping distance. This is because a rolling tire has more grip than a sliding tire. The ABS system is designed to grab and release the brakes very rapidly at all four corners to prevent tire lock-up and keep each tire spinning, while still allowing you to slow the vehicle as quickly as possible.

5 Common Reasons the ABS Light Comes On

There are many causes which could make an ABS light come on. It doesn’t always mean there is a problem with the anti-lock braking system directly. There could also be a problem with other sensors or components that it communicates with as well.

Below are the top 5 causes of an ABS light coming on.

1) Low Brake Fluid

low brake fluid

The brake fluid has a lot to do with controlling the braking pressure within an anti-lock braking system. There is a brake fluid reservoir which holds the fluid of the anti-lock braking system.

Sometimes there could be a leak from this reservoir which will cause the fluid levels to drop. Either that or excessive amounts of air may exist within the system.

Either way, it may certainly cause the ABS warning light to illuminate on the dashboard.

2) Faulty Speed Sensor

bad speed sensor

There are speed sensors built into every wheel’s hub which calculate the movement rate of that wheel. This information then gets transmitted to the anti-lock braking system.

If it turns out that at least one of the wheels is moving too slowly, the anti-lock braking system will increase the pressure of the brake fluid to allow the wheel to move at a normal speed.

But if there is a problem with the speed sensor, the anti-lock braking system will detect that and cause the warning light to illuminate on the dashboard.

Related: 3 Causes of a Faulty Speedometer (and Repair Cost)

3) Bad ABS Module

bad ABS module

The module of the anti-lock braking system can form corrosion after a while. This is actually one of the most common reasons for why there ends up being a problem with the anti-lock braking system.

If the module is corroded, then it can’t obtain information from the wheel speed sensor. As a result, the ABS light illuminates on the dashboard. It doesn’t even take a lot of corrosion to cause this to happen either. But you will need to replace the module after this happens.

4) Bulb Check

dashboard warning lights

Some vehicles will perform what is known as a bulb check on the dashboard. This check is for the driver’s convenience, so they know the bulbs of their vehicle’s warning lights are working properly.

These lights will usually turn off by themselves after a certain amount of time. In some instances, there may be a glitch in the bulb check which keeps the ABS warning light illuminated after the bulb check is completed.

5) Worn Hydraulic Pump

bad ABS pump

If there is one wheel of a vehicle that moves at a different speed than the other wheels, the wheel speed sensor detects this and then notifies the anti-lock braking system.

Once this happens, the system will activate the hydraulic pump to increase the amount of brake fluid pressure. This will allow the wheels to maintain their traction as they’re touching the ground.

Unfortunately, hydraulic pumps tend to get worn out after years of using them. This would certainly cause the ABS light to come on, which means you’d need to replace the pump right away.

Read also: 5 Symptoms of a Bad Intermediate Steering Shaft and Replacement Cost

What to Do When the Car ABS Light Comes on

When the ABS light activates on your car’s dashboard, it signals that something is wrong with the anti-lock braking system. That means if you need to step on the brake pedal quickly to stop your vehicle, then it might not stop as fast as you want it to. As a result, you could end up in a serious car accident.

Basically, the function of the anti-lock braking system is to keep your vehicle’s tires on the road as you aggressively step on the brake. That way, the wheels don’t lock up or skid uncontrollably on the road during the braking process. This is particularly important if the road is slippery or wet.

There are different reasons for why the car ABS light would come on. The main reason is from simply turning on your vehicle. After you put your key in the ignition and turn it on, the computer does a test on the anti-lock braking system to ensure it is functioning normally.

If the computer doesn’t find a problem, the ABS light will turn off quickly. But if the ABS light stays on, it means there is a problem with your anti-lock braking system.

Sometimes you might be driving, and the ABS light will suddenly come on too. In any case, you need to bring your vehicle to an auto mechanic whenever you experience this issue.

They are the only ones equipped to diagnosing the issue and turning which component of the anti-lock braking system needs repair or replacement.

See Also: 3 Reasons Your Brake Lights Won’t Turn Off

Can You Drive Your Car With the ABS Light On?

Just because your ABS light is on, that doesn’t mean you can’t drive your vehicle. In fact, you will still be able to step on the brake pedal and slow the vehicle down.

However, your ability to perform a panic stop will be limited as you run the risk of locking the tires under heavy braking. Locking the tires increases stopping distance dramatically and prevents you from steering until the front tires regain traction.

What you need to do is drive carefully to the nearest mechanic after the ABS light comes on. Brake slowly when necessary but avoid braking quickly or aggressively. If you can do that, then everything will be fine.

The only circumstance where you shouldn’t even attempt to drive your vehicle is if the brake system light comes on when the ABS light is on. The brake system light indicates a much bigger issue with your braking system — a problem which may limit your ability to brake the vehicle at all. Therefore, you would need your vehicle towed to the mechanic if you notice both lights on.

How to Turn Off Your ABS Light

Most of the time, your ABS light will turn off automatically once the issue is resolved. If it does not, you should be able to use an automotive scan tool to delete the stored code and turn off the ABS light. If the issue has not been resolved, the ABS light is likely to return in the near future.

128 thoughts on “5 Causes of an ABS Light to Come On (and What to Do)”

  1. Hello,
    2003 Corolla, the ABS light and the brake lights come on sometimes while driving. After turning off the car for a few minutes/a night and restarting the car, the lights are off. Sometimes can drive the car for 30-40 minutes and no lights come on. Sometimes when driving for 5 minutes the lights come on. Seems random.
    Car still feels like its driving okay.

    Reply
      • Hi Sean,
        I drive a Rav4 2007 4 cylinder, the ABS light comes on sometimes while driving then suddenly turns it sometime later whilst still driving, sometimes it doesn’t turn off until I get to my destination and switch off the ignition. A
        But after turning off the car for a few minutes/a night and restarting the car, the lights are off. Sometimes can drive the car for 30-40 minutes and no lights come on. Sometimes when driving for 5 minutes the lights come on. Seems random.
        Car still feels like its driving okay, no brake issue.
        Come to think that I had just changed all the sensors.
        What may be the cause of this?

      • I’m not sure. There should be a code stored with that ABS light that should help narrow down the problem. Can you tell us what that code says?

        Most auto parts stores should be able to scan the code for free.

  2. Hi, I’m using 2013 Corolla le, I observed that my gear lever is locked at Park position and my ABS light is on. I can only move when I press the button beside the gear lever. Please what do I do?

    Reply
    • Those sound like separate issues. Are you referring to the button on the shifter itself? Typically you have to press that button to move the shifter out of park.

      Reply
  3. My sister had a 2015 Toyota Camry LE 4 CYLINDER.
    ABS light is on.
    I did check brake fluid level.
    The speed sensor.
    The connections of the speed sensors on the back.
    I haven’t checked the ABS MODULE? CAN YOU HELP ME?

    Reply
    • You’ll need to do a more thorough diagnosis to find the source of the problem. The ABS module will throw codes like the main ECU. Can you see if a code is stored for that ABS light? You can find this by using a scanner attached to your OBD2 port.

      Reply
  4. Hi am keneth, I drive a 1998 toyota noah, my abs light is ever on and the ride is extreamly rough , it feels like something is holding the wheels tight especially after moving a distance of around 30km.you just force it to move.someone give advise please.

    Reply
  5. Hi, I’m driving peugeot 407 automatic transmission. My ABS and speed control is showing faulty and we’ve changed all the abs sensors but is still showing faulty. Could it be the speed control sensor that is causing it?

    Reply
  6. My 2002 dodge ram Dakota had the computer replaced with mismatched numbers causing the ABS and brake light to stay on. Took it to Dodge dealer and they couldn’t fix the problem. Truck runs fine but I’m not comfortable driving it now. It has 140k miles. Drives really good.

    Reply
  7. I have a Honda Stepwagon and the ABS light turns on and off when I start the engine. It only seems to do it on cold start. Any idea what this could be?

    Reply
  8. Hi my car is Toyota Yaris ,it’s suddenly stop while driving ,it’s show ABS light on dash board what is the problem,but after5/6 minitues later it’s strat working what is the fault pls give me yr contect Number it’s make is in 2010

    Reply
  9. My ABS light keeps coming on. Had sensors replaced and diagnostic test done. After driving a few kilometers its coming om again! What now??

    Reply
    • I’m dealing with the same issue just replaced sensor and after driving 50 miles light came on again. Scan shows lose wire again, can’t be, it was all replaced.

      Reply
  10. I have 2016 Mazda 2. My ABS and DSC light comes on when i start my car. Usually after start car and drive 1km light go off ( when they go off sometimes they turns on again after 10 sec) I checked my Battery but my battery voltage is okey. There is no any fault codes.

    Also cars with start stop have a sound when we press the start stop button and after shut down the engine and open the door, its like electric motor sound. When abs error stays on that sound also not coming.

    Reply
  11. I have a Buick Regal that the ABS light comes in if I turn the wheel all the way in either direction. If I turn the car off and back on … it goes off… why?

    Reply
    • I would inspect the wiring on the front wheel speed sensors if the insulation is rubbed away or if the wires are pinched or damaged. Do all your steering wheel controls work when you turn the wheel all the way? If not, there may be an issue with the clock spring in the steering wheel.

      Reply
  12. My abs and check brake system light is on but the mechanic checked pads, hydraulic pump, wheel sensors, etc and all are good- Maybe a bad module– The scanning device came up with 2 wheel sensors detected, but he said they were not the problem as he installed them and the light still didn’t go off, but still showed them as the issue? What now?

    Reply
    • Why did he install them if he didn’t think they were the problem? It sort of sounds like an electrical issue, but not with the sensors themselves.

      Reply
  13. I have a 2013 Dodge Grand Caravan SXT. The ANT-SKID light intermittently comes on for no apparent reason. If vehicle gear is in park and running you cannot shift it into gear. If you turn off engine then restart, the light clears and you can put into gear and drive. Today the light came on and shortly after the CHECK ENGINE light came on. An AUTO-ZONE guy hooked up his code reading device and it read BRAKE STOP SWITCH was the problem. The problem with that is, I was told if your brake stop switch is bad, the brake lights will not work, mine were working fine. The CHECK ENGINE CODE read BRAKE STOP SWITCH… CODE INVALID

    Reply
    • I’ve removed the brake switch on my vehicle and had working brake lights. There was another circuit that controlled the brake lights as a backup system.

      I would check your grounds, honestly. It sounds like an electrical issue since it’s affecting both the traction control light and the brake lights.

      Reply
  14. 2002 Chevy blazer. Both the ABS and emergency brake lights are on. Looked over the system and can’t find a problem with air in the system or low fluid. Any ideals?

    Reply
    • Check the wheel speed sensors and wiring. If you can’t find anything, a scan tool may be able to help determine if there is a problem with any of the sensor data.

      Reply

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