VW BRAKE SYSTEM ABS:

ABS dash lights

Volkswagen Brake System ABS Control Module operates the ABS system based on data received from its various sensors.
Why is the ABS service light on?
When the Volkswagen ABS service light is on, the anti-lock braking system is disabled due to malfunctioning.

Your vehicle's regular brakes should work properly, but the ABS system, which prevents the vehicle's wheels from locking up when braking, does not. If your vehicle is equipped with stability control or traction control, this function will also be disabled.

Each ABS sensor is mounted on each wheel to monitor its speed. If one wheel spins more slowly than the other three when braking, it indicates that it is locking up and could cause you to skid and lose control of the steering. ABS usually intervenes by quickly pumping the brakes at the locked wheel, allowing the wheel to spin out, and allowing the driver to maintain braking and steering.

What causes an ABS brake system to malfunction?

  • Wheel speed sensor that is damaged or covered in road dirt
  • Broken wire between the sensors and the ABS controller
  • An ABS controller that has stopped working

When you get behind the wheel of a Volkswagen, start the car, and notice that the letters “ABS” light up on the vehicle's dashboard, there may be a problem with the vehicle's anti-lock braking system. Our Peoria Volkswagen service department is ready to share some of the reasons why your ABS light might come on. Why is the ABS service light on? When the Volkswagen ABS service light comes on, the anti-lock braking system is disabled due to a malfunction. Your car's normal brakes should work fine, but the ABS system that prevents the wheels from locking up while braking is not. This feature will also be disabled if your vehicle is equipped with stability control or traction control. Each ABS sensor is mounted on each wheel to monitor its speed. If one wheel spins more slowly than the other three when braking, this is a sign that it is locking and you could skid and lose control of the wheel. ABS usually intervenes by quickly applying the brakes to a locked wheel, and spinning it, so the driver maintains braking and steering. The causes of ABS failure are as follows: The system fuse has blown Damaged or covered wheel speed sensors Broken wire between the sensor and ABS controller ABS control stopped

ABS dashboard light

ABS WARNING LIGHTS

The ABS warning light/anti-skid brake light will come on or start flashing when there is a malfunction with the ABS brakes. The ABS control module continuously performs diagnostic self-checks. If it finds a problem, it will shut down the system. There maybe a problem with the wheel speed sensor, ABS Differential Sensor, power relay for the ABS module/pump, or it may indicate a low fluid level in the ABS fluid reservoir.

If other lights come on with the ABS brake light, then there could be something seriously wrong with the braking system such as a hydraulic problem or a serious brake fluid and /or pressure loss. If this happens the vehicle may not be safe to drive. The safest thing to do would be to have the vehicle towed. Please call us to schedule a towing. A basic service brake system problem could lead to brake failure which could endanger yourself as well as others on the road.

ABS WHEEL SPEED SENSOR

An ABS wheel speed sensor malfunction will signal the ABS light to illuminate and disable the traction and stability control systems.
In some cases, the speedometer will stop working and the Check Engine Light will also illuminate. In some Volkswagen cars the sensor is an integral part of the hub and therefore the entire hub unit must be replaced. Wheel speed sensors can be damaged when going over rough terrain. There are several other reasons that can affect the ABS system such as: corrosion, worn bearings, or other problems in the ABS system which can set a wheel speed sensor trouble code. The sensor can even get damaged when other work is being performed on your car. Any problem with the ABS system needs to be diagnosed before the wheel speed sensors are replaced.

ABS WHEEL SPEED SENSOR

The anti-lock brake system (ABS) differential speed sensor automatically transmits the speed of the differential ring gear to the ABS control module. Using this data, the control module calculates the vehicle speed. Not all Volkswagen vehicles with ABS have an ABS differential sensor. Some vehicles utilize individual wheel sensors instead of a single differential mounted sensor. If this is the problem the ABS light will illuminate on your dash.

ABS PUMP

The anti-lock brake system (ABS) pump provides supplemental brake fluid pressure (in addition to the pressure created when the driver applies the brakes) necessary to operate the ABS system. The ABS pump is the hydraulic valve unit. On most cars, the control module can be replaced separately. The ABS light will illuminate if there is a fault with the ABS system. The Volkswagen Brake System – ABS Control Module are calibrated for suspension, ride, steering and overall general handling of your Volkswagen.