Why is my ABS light on? (5 common causes)
Your car’s anti-lock braking system (ABS) helps keep you safe and in control of your car by braking suddenly in an emergency.
If something goes wrong, your first clue is that the ABS light on your dashboard will come on. Here are some of the most common reasons why your ABS light comes on and whether it’s safe to continue driving.
Common Causes of an ABS Light On
1) Faulty Wheel Speed Sensor
One of the many reasons why your ABS light may come on or stay on is a faulty wheel speed sensor. Wheel speed sensors are located at the center of the wheels, and sometimes in the transmission. Anti-lock braking systems rely on data from wheel speed sensors, which determine how fast the vehicle’s wheels are moving.
This data is sent to the ABS, which, after receiving data from one or more wheels, determines that one or more wheels are moving slowly compared to the others and releases the brake fluid pressure.
This allows the wheels to resume movement. If there is a problem with the wheel speed sensor, whether it is filled with debris or other damage from normal driving, the ABS will not receive data to control wheel movement.
2) Hydraulic pump or valve not responding
When the ABS receives data from the wheel speed sensor, it releases a hydraulic valve to increase brake fluid pressure and prevent the wheels from losing grip.
This valve or pump is vulnerable to damage, possibly due to internal wear. One cause of this internal wear could be dirty brake fluid. It could be that your ABS light is on.
3) Blown fuse
Like most systems and electrical components, the anti-lock braking system has its own fuse. Before you replace expensive parts or spend time troubleshooting, make sure your ABS fuse isn’t blown or burned out. A quick check of your fuse box can save you a lot of trouble.
4) ABS module failure
Another reason the ABS light may come on is a failure of the ABS module itself. This can be caused by corrosion of the cable, which can increase resistance in the cable and cause delayed or lack of communication between the wheel speed sensors and the ABS. Even a small amount of corrosion can be enough to cause the system to malfunction.
5) Low brake fluid level
Like most braking systems, the ABS utilizes hydraulic brake fluid to regulate pressure. A low fluid level in the reservoir can cause the ABS to stop working and the ABS light to stay on permanently. Too much air in the system is also a possible cause.
How the ABS system works
The primary role of the anti-lock braking system is to protect you from accidents and to prevent you from losing control of your car during emergency braking (such as a skid).
ABS is a safety system that detects when the wheels stop rotating when you apply the brakes while your car is moving, and releases the brake fluid pressure so the wheels start rotating again.
It can do this because the system is fully automatic. This process may sound simple at first, but its importance lies in stopping or braking the vehicle in a controlled manner while greatly reducing the risk of losing control.
This prevents the vehicle’s wheels from locking or sliding uncontrollably. However, your vehicle’s ABS is subject to wear and can also fail. If your ABS light comes on, it’s best to have the problem fixed as soon as possible.
Is it safe to drive with the ABS light on? If you brake suddenly on a slippery surface, your vehicle may not be able to stop as intended, increasing the risk of an accident.
If both the ABS light and the brake system light are on, you should consider this an emergency and stop driving immediately.