ABS Sensors: Usage & Functionality

Author: Arslan Khan

Over the years, the implementation of innovative technology to improve automobile safety has enhanced quite impressively. This is where the effectiveness of ABS (Anti-lock Braking System) proves its mantle. These systems are mainly present across newer automobiles offered by various manufacturers and can also be equipped from external sources.

What is an Anti-Lock Brake Sensor?

For most of us who aren’t aware of the anti-lock brake sensor, it is a type of tachometer which calculates the rotational speed of a particular wheel and forwards the information to the vehicle’s Engine Control Module (ECM). Hence, the ABS sensor is popularly called the ABS brake system sensor or wheel speed sensor.

  • In a four-wheeler, different wheels do not rotate at the same speed. Under this condition, the ABS sensors forwards the speeds of every wheel to the ECM. With the help of this information, the ECM regulates the locking up of the wheels. It is important to know that, the use of the ABS brake is faster in comparison to manual brakes. Moreover, the presence of ABS works to reduce or completely omit the grinding noise in automobiles.
  • Earlier, the ABS configuration involved the sensors to be placed outside the wheel hub in sections such as the differential housing and steering knuckle. However, in the present time, the ABS sensor is attached with a ring gear. This ring is fixed on components like the brake rotor as well as brake drum. With the availability of modern ABS sensors, the latest systems are maintained in the wheel hub assembly. One must keep a note that, based on the type of braking system, the vehicle may possess either one or a maximum of four ABS sensors.

ABS Functionality

What does ABS exactly perform? The primary function of ABS system is to stop the wheels from locking at the time of braking which automatically regulates the braking force in the stirrups. In simple terms, each round manages its own speed sensor and control unit, which in turns sends information about the speed concerned with every wheel. In case the control unit receives a signal highlighting the wheel is blocked, then pressure is lowered in the brake system. Considering a heavy braking system, ABS braking force applied to regulate the adhesion occurs to block wheels as well as the following release of wheels in quick succession until the automobile stops. It is important to mark that, the advantage of ABS is also linked to stability control for the vehicle.

Symptoms of ABS Sensor Failure

There are chances that the ABS sensor of your vehicle can fail due to road debris and similar reasons. Therefore, inspecting and cleaning the sensors as per the instructions specified in the user manual is crucial for maintaining its optimal performance.

One of the prime indications of a defective ABS sensor focuses on the illumination of the ABS light in your vehicle's dashboard. The other symptoms of a bad wheel speed sensor are linked to the significant loss in traction while you are driving on a slippery road.

Apart from the defects noticed in the ABS sensor, the wiring or connectors can also end up being the culprit when they fail to transmit the necessary signals to the ECM. Therefore, before you plan to replace the ABS sensor, it is a smart habit to inspect all the related components and confirm which element is actually faulty.

Some other important factors leading to ABS Sensor failure are:

Unresponsive Hydraulic Pump or Valve

Whenever the wheel speed sensor informs the ABS regarding the wheels which are moving at diverse speeds, a hydraulic valve takes charge for increasing the brake fluid pressure in order to prevent the wheels from dropping traction with respect to the ground. Similar to all pumps and valves, the ones connected to the ABS are accountable to become unresponsive. It can be caused due to internal wear usually from dirty brake fluid.

Stumpy Fluid Levels

The ABS braking force relies on the fluid which helps regulate pressure. In case the ABS fluid reservoir is less, or there is too much air present in the system, the ABS wouldn’t be able to accomplish its designated action.

Looking at the above-mentioned pointers, it is clearly revealed that for automobile safety and driving secureness, the presence of ABS sensors is quite vital. You can surely check with your car manufacturers or any registered expert regarding the different versions available in the market.