Why is My Cruise Control Not Working?

Cruise control is one of those creature comforts that’s often taken for granted in our vehicles, especially on long drives and road trips with extensive stretches of highway. While you might usually pay little attention to the inner workings of your cruise control system, it can become quite obvious and frustrating when it encounters a problem that prevents it from engaging properly. 

How Does Cruise Control Work? 

Cruise control first became widely available in American cars during the mid-20th century, and made use of a fully mechanical system, whereas modern cruise control systems rely on electronics and computer control to keep your vehicle traveling at the correct speed. 

In vehicles that use a traditional throttle cable, either a vacuum actuator or electronic servo is used to pull the cable and open the throttle body to allow in the proper amount of air needed to maintain that speed. In modern drive-by-wire systems, the actuation of the throttle body is completely controlled electronically as opposed to pulling the throttle cable. 

Vacuum actuated cruise control system
Hans Haase, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Why Isn’t My Cruise Control Working?

There are various reasons your cruise control system could be having problems, but some common issues include: 

Bad Fuse

Since modern cruise control systems rely on sensors, computers, and actuators to accomplish a steady speed, even the smallest problems in the electrical system of your vehicle can result in the inability to activate it, including a single blown fuse. 

Fuses “blow” to prevent damage to the sensitive electrical components, as they can be easily accessed and replaced from the fuse box. Different vehicles will have varying locations for their cruise control fuses, but if you can track it down and notice a visible gap in the wire within the fuse, you know your fuse might be to blame. 

Intact fuse next to a blown fuse
Cqdx, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Fuses are usually a cheap and easy replacement, often located in the fuse box within your engine bay or under the dashboard. Always ensure you’re using the proper size and current rating if replacing it yourself. If you complete the replacement and the fuse immediately blows again, there may be a more serious issue within your electrical system that needs to be addressed. 

Faulty Cruise Control Switch

While we don’t often think about the switches and buttons within our vehicles as needing to be replaced, they can break just as any other component. Over years of use and abuse, they can fail and become unable to activate your cruise control. This can happen due to being pressed too hard, aggressive interior cleaners and solvents, or liquids getting into the electronics.

Cruise control switch
Santeri Viinamäki, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Faulty Brake Light or Brake Pedal Switch

Your cruise control system is deactivated when the brake pedal is pressed, but when the brake pedal switch is not working the system may prevent itself from activating as a safety measure. 

A similar situation can occur when a brake light has failed, as the system may also stop itself from engaging when one of the lights is not working properly. 

Broken Physical Components

If your vehicle uses a mechanical cruise control system, your issue may be traced back to a simple failure of a physical component. Loose throttle cables can prevent the throttle body from being properly opened, or a failed actuator will be unable to pull the cable at all. 

Unfortunately, various possible mechanical failures could occur in your cruise control system. The best way to track down the source of your problem is to bring it to a trusted automotive service professional and have it diagnosed. 

Failing Speed Sensor

The purpose of a speed sensor is pretty self-explanatory. Without the proper information on your car’s current speed, the cruise control system will be unable to engage. Speedometers in many vehicles also operate on measurements from the speed sensor, so you may notice it displaying inaccurate or unusual readings if this is your issue. 

Cruise Control Service in Naperville

The ASE-certified technicians at Becker Service Center in Naperville, Illinois have the expertise and equipment to diagnose and repair your vehicle’s cruise control system no matter the issue. Call or schedule online with us today!