The light will automatically be switched on whenever the car detects that you are driving under slippery weather conditions.
The VDC is playing the role of reducing engine power while applying brakes to wheels that have lost control. In most cars, the slip light on the dashboard will turn on indicating you are approaching slippery roads. Malfunctions in the VDC light will see the VSC OFF light coming on.
Vehicle Dynamic Control (VDC) works with the ABS to offer traction to the car. Most of the time the driver experiences some form of vibrations on the braking pedal when the VDC is on. This should not be a cause of alarm because it indicates the system is working perfectly.
The confusion on the VDC arises when drivers become overconfident over their driving skills and rely solely on traction control. Note that over steering under high speeds can lead to serious accidents. Having the VDC does not eliminate the need to be cautious while driving on the roads. When making modifications to your car it is advised that you do not change struts, shock absorbers, stabilizer bars or springs as these will interfere with the car’s VDC system. The VDC will also be affected when you switch to non-standard brake rotors and pads.
In some instances, the VDC will come on/off when you are riding through bumpy roads. This should not be a cause of concern. Wheel sensors attached to the wheels could be responding to the uneven roads.
How does it work?
Modern cars come equipped with traction control systems to prevent under/over steering on slippery roads. The moment the VDC is activated you will have brakes being applied to one or more wheels that are skidding. This is followed by a reduction in engine power. One or two of the plugs in the combustion chambers will be suppressed. In addition, there might be a reduction in fuel in one or more of the cylinders. The effect of all this is to reduce engine power while giving the driver power over the steering wheel. In cars that have a turbo, the traction control will reduce boost by actuating the boost control solenoid.
The VDC was designed to give drivers more control over their cars during slips. This is done by giving the car stability when driving on snowy roads. The car wheels have sensors that detect when one of the wheels rotates faster than the rest. This is done with cooperation with the ABS and onboard computer.
Common Issues with the VDC
The traction control does malfunction with continued usage. When this happens, you have the light on all the time. Here are top causes for a faulty VDC light:
Faulty wheel sensors
Sensors are attached to each of the car wheels. The function of the sensors is to detect any shift in the wheel angles and send this information to the onboard computer. As you accelerate, the sensors will detect the speeds of each wheel. If one of the wheels is slipping and rotating faster than the rest, the ABS will be activated on these wheels.
The car will also reduce car power and this gives you better control of the car. When the wheel sensors are faulty then it will not detect any over/under steering and this means the light will continue coming on/off. Wheel sensors often accumulate debris and this makes them ineffective. You can fix this by taking your car to a mechanic who will clean out the sensors while ensuring that the wiring is in good condition.
While the main function of the VDC is to help you keep the car stable while driving on slippery roads the light will malfunction when the roads are extreme. In some instances, there those who drive their cars on extremely bumpy or snowy conditions. The traction light will remain on and will be of little help. However, once you start driving on clear roads the traction control will start operating as normal.
Faulty steering angle sensors
Each of the wheels with traction control has steering angle sensors. These sensors will detect the angle of the wheel while navigating poor roads. The sensors can malfunction as it is located on the steering column. This will cause the traction control lights to come on even when you are driving on smooth roads. A mechanic can take a careful look at the sensors and clean them. They can also check the wiring.
Onboard computer programming issues
The wheel sensors are in constant communication with the onboard computer. The computer will detect slipping of the wheels and send signals to the ABS or the engine to cut power. As with other computers the cars ECU can develop errors. These errors will cause the VDC light to come on when no wanted. You can solve this by reprogramming the computer. However, reprogramming is a serious issue and you will need to contact the car’s manufacturer or a certified mechanic.
Bad steering rack
A good steering wheel will help you take control of the car when you are going through slippery roads. The rack is positioned on the steering wheel and uses hydraulic fluid to turn the steering wheel. When rack is not working as expected you are going to have problems steering the car even when the VDC light is activated.
The VDC is an essential component of the car’s traction control system. The system utilizes information passed on from wheel sensors on each wheel. Anytime you are driving on slippery roads and start losing traction, the VDC will be activated. The VDC works with the ABS to lock wheels that rotating faster than the rest.
The wheel sensors also pass information to the onboard computer and this causes it to reduce engine power. After activation of the VDC you will notice that you have more control of the car than before. The VDC light can at times become faulty and keep coming on even when driving on smooth roads. You should check the wheel sensors and ensure that they are not dirty.