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

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.

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.

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

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.

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.

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

  1. Hi I am driving a 2008 Toyota Corolla 1.6. When I’m driving uphill, it shows a check ABS light and when the speed is 100 kph it shakes and make a crrrrr(cracking) noise. Can you tell me what is the problem?

    Reply
  2. Hi I recently had all 4 brakes replaced on my 2011 Lincoln MKX and just a couple of weeks afterwards my ABS lights came on. One mechanic told me he thought it is probably the wheel sensor but he would have to check which one if not all 4 since I had just had the brakes done, but when I took it to him to look at he then said its the entire ABS system. How can I tell if he’s trying to make a lot of money for the ABS system instead of just a sensor? Thanks

    Reply
    • You could go to O’Reilly’s or an auto parts store that has testing equipment with abs functionality and test it for yourself it’ll tell you what tire it is or if it’s the actual ABS system itself

      Reply
      • If it’s the actual ABS module that is pretty spendy but if it’s one of the tires then it’s just the wheel speed sensor and it could also be one of the connectors or wires that’s going to and from the ABS module computer you can get an volt reader and do that test yourself bc all kinds of vids on YouTube

  3. My ABS light goes off and on my engine light also goes on at the same time but stays on longer than the ABS ..I needed roaders and brakes that my guy already fixed. Well the ABS light and engine light are still going on but today when they both went on and the car stop but started quickly ..I noticed that this almost happened before the brake job also

    Reply
  4. my abs light will come on and it will go off and sometimes stay off for weeks and then come on again I tried to use my scan tool but must not work on abs problems. I have tried spraying brake cleaner on the sensors on front wheels

    Reply
    • Correct, you need to use a scanner that’s specifically compatible with ABS. If you don’t want to buy a new one and have an Autozone near you, they’ll be able to scan it for you for free.

      Reply
      • What if your ABS light comes on right before your car stops running and won’t crank back up until it’s jumped off.

  5. My ABS light comes on after driving my car for approx 2 kilometer then stays on but my brakes seem okay had the disc pads checked had the calipers checked replaced the pistons in the rear disc brakes, any ideas what is causing this?

    Reply
  6. Hi my abs light is on had it put on a diagnostic machine it said front wheel drive sensor replaced with a new one still showing same problem can some one help thank u
    Ralph

    Reply
  7. The ABS light come on and it makes my want to almost stop ad I don’t have my foot on the brake at all. This didn’t start until my car was hit on the front in an accident.

    Reply
  8. I was driving my car Vauxhall Corsa ABS light come on lost power and car stopped by itself wouldn’t start for about 10 minutes started and no light on can anybody help with this

    Reply
  9. Hi I had a Toyota Camry hybrid 2011 . There are ABs sign displays coninuely and break stop working . One of the my mechanic scanned and recommended to change booster . I replaced booster system just 2 days ago . Again ABS light is on for short period . Very confused . Please advice .Thank you

    Reply
  10. Hi i drive a polo 6 sedan…I HV a problem with my car I was driving on a gravel on a rainy road was slippery so I had to forcefully take out my car off that steep road ,now on the dashboard it displays ABS lights …what could be wrong …

    Reply
  11. I’m driving a ford ecosport. The abs and brake lights come on and the speedometer drops to 0 while I’m driving. It will feel that I’m losing power and the steering wheel feels unsteady. I took my car to my ford dealer but they told me that there is no problem…. I don’t know what it can be and feel very unsafe.

    Reply
  12. I have a 2006 Mitsubishi eclipse brake pedal is spongy one shop says and 2say not and no light on what is the problem what to do

    Reply
  13. I drive a KIA PICANTO 2006, my brakes get sticking when the ABS light on. it then stops the car from moving until I putting it off for some time then the brakes get freed before I can move. What could be the cause? can someone help me?

    Reply
    • First, check to make sure your brake fluid is topped off. If it’s below the “low” line, fill it before driving anywhere. If this is the case, you should probably bleed the brake system to make sure no air got in there as well.

      It could be a number of issues including a bad wheel speed sensor or ABS module. I’d bring the car to a local mechanic to get it checked out if I were you.

      Reply
    • A persistent ABS light could mean a problem with the wheel speed sensor or ABS module. I would get the code scanned at a mechanic to know for sure.

      Be aware that while the ABS light is on, the anti-lock brake system may not function if you were to slam on your brakes, causing one or more tires to lock up.

      Reply
  14. Hi friends
    I have a Ford Laser, in this the ABS light comes on with the ignition key trend on, even after the engine is on the ABS light remains, but the brakes are not bad car drives abut 4,5 kilo miters and you stop the engine then start again the ABS light goes off. but in a while it comes again, tell me what can course this. and I noted that wen ABS is working (the light is off) on a down hill wen you apply breaks it gives a vibrating Noise and the pedal vibrates.

    Reply
  15. hi my toyota camry 2000 model is showing abs for long time now and my mechanic said he didnt see anything wrong that i should drive it like that please how do i fix it.

    Reply
    • I wouldn’t drive it like that. If you have to hit the brakes hard, your wheels could lock up and make the vehicle much harder to control. It would also increase your stopping distance.

      I would take it to a mechanic who is able to diagnose the issue.

      Reply
  16. “In fact, you will still be able to step on the brake pedal and slow the vehicle down. ….
    However, you cannot perform any kind of emergency stop by slamming the brake pedal quickly.”

    What utter rubbish! How did drivers perform emergency stops in pre-2004 vehicles?
    I think the author is thinking of ‘servo assisted brakes’.

    Reply
    • You’re absolutely right, I routinely brake hard without ABS on my track car. Thanks for the feedback, I’ve updated the article for clarity.

      Reply
  17. my abs light stays on and my break light stays on I have don’t everything I know to do will you help me I have a 2004 Ford tausus

    Reply
  18. Hi I’m driving a Hyundai Tucson 2005 model it’s brakes started to be very hard in a way that the car takes q long run to stop with an qba warning light on yet it’s an automatica

    Reply
  19. Had my rear brakes replaced on my GMC Yukon. Now the ABS and brake lights are on. I took it back to the place that did my brakes and they are saying they can’t find a problem. I didn’t have this issue until they replaced my brakes. What could it be?

    Reply
  20. hi,

    I have Nissan Pathfinder 2014. when I switch left/right signal on the signal click sound faster than normal and soon after ABS light got turned on. can you please help or tell me what would be wrong?

    Reply
    • You could see if the two systems share a common circuit. Did you say both turn signals are clicking faster than they’re supposed to?

      Reply
  21. Hi –
    I have a 2017 Honda Accord
    All 4 indicator lights came on
    simultaneously:
    The ABS / VSA/Brake/Caution
    Exclamation lights came on
    They have gone off &
    Also come back on again

    The dealer diagnosis Is that the circuitry is faulty &
    will cost 1500+Labor

    What causes this problem
    What should be done
    Will it be a recurring issue
    Should they be checking other things
    &
    Can car be driven like this safely
    Does it matter if it is dry or wet road conditions
    Please direct best suggestions
    Thanks

    Reply
    • What circuitry is faulty? I don’t know what systems have been disabled due to the issue so I can’t say if it’s safe to drive like that. It’d be best to go off of the dealer’s recommendation in this situation.

      Reply
  22. The abs light blinks on and off when the engine is turned off. When the car is started , the abs light goes off. Is the normal on a Subaru Forester?

    Reply
  23. I changed all full wheel sensors also I change the power booster pressure sensor and my brake light still stays on what in the world could be the problem please help me

    Reply
    • It could be an issue with the ABS module. Sometimes brake control module circuits go bad over time and the module will have to be replaced or repaired to make the light go away. I would start performing some diagnostic tests to see if that is actually the issue before throwing any more parts at it, though.

      Reply
  24. my abs light stays on when driving but my brake system light does not stay on. I’m not having any braking difficulty but I’m still not happy with my abs light on. I have a Hyundai Tucson 2010 module and I need an advice about the problem

    Reply
    • First, get the ABS code scanned. Next google your make/model along with the code and see if you can find any information on TSBs or common related problems that affect the car.

      Reply
  25. I am deicing Toyota yaris 2009 model. ABS and handbrake light stays on and speedo also not working since I had my front wheel bearings replaced. Took vehicle to Toyota. They replaced both speed sensors. Drove the vehicle for about 30 Kilometres and the same problem came back. Please advise.

    Reply
    • I’d recommend having the computer scanned for codes. Your best bet might be to take the car back in, either to the same shop or a different one.

      Reply

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