Cruise control can be very convenient when on a long drive or when on the highway. By setting a speed, you can relax your foot and let the vehicle maintain speed. More modern cruise control systems even allow you to maintain speed and a certain distance behind the vehicle in front of you. When cruise control fails, it can be annoying, but when it fails suddenly it may be dangerous. A sudden failure by the cruise control may mean your vehicle is rapidly decelerating. Even when cruise control is on, it is important to remain a vigilant driver.

Cruise control systems have changed as cars have become more modern. Newer cars use a fully electronic setup to maintain speed and may be able to maintain speed and distance behind the car in front of you. These systems are controlled through the vehicle’s computer or ECU (electronic control unit). Older cars may use what is called electromechanical cruise control. In this setup, a vacuum actuator is physically connected to the throttle by a cable or chain. The cable adjusts to increase or decrease throttle position based upon the actions of the actuator. A mechanic will let you know what kind of setup you have on your vehicle.

A failed cruise control system can be a signal that other repairs may need to be made soon. By examining the cruise control, the mechanic is likely to also inspect other systems on the car including the brake lights and speedometer. While driving without cruise control may be an inconvenience, a sudden failure of the cruise control system could be potentially dangerous for a driver who is not vigilant. If you notice that your vehicle’s cruise control has stopped working you should have a mechanic check it to determine the nature of the problem.