VDC Light explained
The Vehicle Dynamic Control (VDC) utilizes several sensors to monitor the driver and vehicle. When the VDC system detects an issue, the lighted indicator on the instrument panel flashes.
Many cars and trucks come standard with traction control and anti-lock brakes. Traction control and the anti-lock brake system use wheel-speed sensors to prevent the wheels from slipping during acceleration. VDC light illuminates when one of these systems detects a single wheel speed is faster than the other (the wheel has lost traction.)
Why the VDC light comes on
As with all vehicle components, traction control systems and VDC lights may experience problems. The traction control sensors are attached to each wheel, which leaves them exposed to all kinds of road conditions. Water, dirt, and road debris may render the traction control sensor dirty or damaged, which could prompt the VDC light to turn on.
When the VDC light stays on, it means a wheel is slipping and there is a possible traction control failure. Diagnosing an issue with the traction control system usually requires code-reading tools to pinpoint the problem. If the issue is with the VDC light, it is generally because the driver turned off the traction control switch or there is an electrical malfunction within the dash.
When to turn off the traction control switch
The traction control system cannot increase the traction between the wheel and road surface. In most road conditions, it may be wise to keep the traction control activated. However, if the vehicle gets stuck, the traction control could prevent the tire from gaining enough power to get itself unstuck. By turning off the traction control, the driver can accelerate to gain traction.
The VDC light was designed to warn drivers of hazardous road conditions by coming on when the traction control sensors detect an issue. By alerting the driver of possible danger, it allows the driver time to slow down to stay safe.