The ABS sensor is a key component of the anti-lock braking system that monitors the speed of each wheel in real time. Its role is to prevent wheel lock-up during sudden braking by sending information to the electronic control unit.
Thanks to it, the vehicle retains controllability and stability even on wet or slippery road surfaces.
What is the ABS sensor?
The ABS sensor is an electronic device mounted near the hub of each wheel. It measures rotation via an impulse ring and sends a signal to the ECU. When the system detects a rapid reduction in the speed of a specific wheel, it activates the brake pressure modulation module.
There are two main types:
- passive inductive sensors – generate a signal through a magnetic field and do not require external power;
- active sensors – use the Hall effect and operate accurately even at low speed.
Active systems are more sensitive and are used in most modern cars.
How does the ABS system work?
During sudden braking, the ABS prevents wheel lock-up by reducing and restoring brake pressure multiple times within a second. Modern systems can modulate pressure up to 15-20 times per second. This allows the wheels to maintain minimal rotation and grip with the road surface.
The standard configuration includes:
- four sensors – one on each wheel;
- electronic control unit;
- hydraulic module with valves;
- pump for pressure regulation.
The result is a shorter braking distance with controlled handling.
Symptoms of a faulty ABS sensor
A sensor failure leads to system deactivation. The most common signs are:
- ABS warning light on the dashboard;
- wheels locking during sudden braking;
- unusual vibrations in the pedal;
- problems with the traction control system.
The causes are usually contamination, a broken cable, or a damaged impulse ring.
Diagnosis and solution
The first step is a computer diagnosis to identify the fault. In most cases the most reliable solution is to replace the defective sensor. However, repair rarely guarantees long-term reliability.
The ABS sensor is small but a vital safety component. If there is an indication of a problem, do not delay inspection, because the proper functioning of the system can prevent an accident.
If you suspect a malfunction in the ABS system, schedule an appointment for a professional diagnosis at our service center and ensure your vehicle's safety today.
