Why is the abs sensor lit?

Modern car is equipped with various indicators of the state of the vehicle. Most systems are electronically controlled, but the reverse reaction, with which the computer communicates with the driver, is the blinking of light bulbs or some kind of light elements.

Young drivers may be alerted by the situation in which the ABS light is on. In this case, there is no reason for a critical panic, because the main braking system should remain normal.


  • 1 The work of the ABS in the car
  • 2 Problem identification
  • 3 Independent solution of the problem

The work of the ABS in the car

The help of the anti-lock system is to minimize driver and road issues when you press the brake pedal. Do not lock the wheels, causing the car to turn or loss of controllability. The car slows down and keeps moving straight.

The ABS helps with impulse braking by rotating / blocking the wheels in a specific sequence. The skid during operation of the system is practically eliminated, and there is a smooth decrease in vehicle speed.

what are the reasons for the ABS light

The ABS system includes the following elements:

  • hydraulic unit;
  • electronic sensors located on each wheel;
  • an element that monitors the correct operation of the hydraulic unit;
  • indicator light on the dashboard.

Problem identification

If the ABS lamp comes on while driving, this is a signal that the entire system or its individual elements are not working properly. The normal sign of efficiency is a fire at its start, and after a few seconds it should go out.

At this time, testing the performance of the ABS. Signals are sent to all sensors, and response pulses come from them.

When the ABS icon lights up and does not go out even while driving, this may be due to the following problems:

  • problem with communication with any sensor on one of the wheels;
  • breakdown in the control unit;
  • poor contact in connecting cables;
  • fail in all sensors.
See also: Check ABS sensor tester

Breakage of wires happens while driving, as well as during intense vibrations on a bad road. Connections in the connectors weaken and a gap occurs. These malfunctions are solved independently without referring to the specialists of the auto enterprise.

when the ABS light comes on when driving

Also, the reason why the ABS sensor is lit may be due to the fact that debris or dirt has hit the working surfaces of the sensor located on the wheel. It is enough to wash the car with high quality, and the indicator will go out.

It is necessary to remember how long you have visited the service station, because inexperienced craftsmen carry out wheel diagnostics by throwing the wires away from the sensors. After this unfortunate experts forget to return everything to its original position, and the light on the panel continues to burn.

Faults with the control unit will be more problematic. You can identify them using the on-board computer, which will give the system error code. According to such data the problem with anti-blocking is calculated. It is unlikely that it will be possible to resolve the issue on your own, so you will need to go to the car-care center.

Independent solution to the problem

For those who are accustomed to act decisively, it is advisable to open the hood and find an electronic control unit. Disconnecting the battery, inspect the case for damage or water ingress. If necessary, you can dry everything from excess moisture.

In the fuse box, we check all the connections. At the same time, it is necessary to know that several fuses can be used simultaneously for the operation of the ABS.

what are the problems if the ABS light comes on while driving

It is necessary to check the wires going to the wheel from the computer. They can be disconnected or frayed during operation. Such diagnostics is carried out on a jacked up car.

В некоторых случаях достаточно разогнаться на ровной пустой дороге и резко затормозить. При этом все системы должны сработать правильно, а индикатор обязан погаснуть, если произошел временный fail в ЭБУ.

In cases where the ABS is working normally, but the lamp still lights, it is enough to open the battery terminal for a few minutes to reset the system. Everything must come back to normal.

See also: Device and principle of operation of the vacuum brake booster and how to check it

When none of the suggested cases of putting the display in order did not help, you need to boldly go to the car-care center in order to identify and eliminate the error using computer-aided diagnostic.