Cruise Control Not Working: The Possible Reasons

For safe driving, it is essential to have all the car components fully working. Cruise Control System (CCS) also comes under the list of vehicle components that have to be fault-free. Many people do not take it seriously when cruise control not working, but you cannot use this system at all without fixing the problem. A faulty CCS can affect the acceleration of the vehicle. Therefore, users must know the reasons why cruise control stopped working to troubleshoot the issues.

What Is Cruise Control?

Cruise control is a common module in the latest design vehicles. This system assures that a driver can drive a car at a constant speed without applying force on the accelerator pedal again and again.

Before becoming a fully electronically operated system, cruise controls encountered many changes in their configurations. While the earliest CCS had a mechanical system, it ran on the vacuum and electro-mechanical processes in later stages. The latest version of cruise control design is adaptive CCS that allows users to maintain a safe distance between their cars and other vehicles right in front of them.

Cruise Control Working Process

It was in the late 1950s when vehicles started to get this system. Although only selective models had this feature back then, now it has become an indispensable part of all the cars. It will be wrong to think of it as a luxury feature. Instead, it is a dependable system that drivers often rely on to avoid accidents.

cruise control won't engage
Cruise control is a significant part of a car. (Source: Santeri Viinamäki / Wikimedia Commons)

The cruise control system regulates the car speed by adjusting the accelerator position. But the pressing of the pedal is not involved in this system. Cruise control connects the throttle to an actuator valve with the help of a cable. The throttle valve controls the air intake of the engine and thus regulates the engine speed and power.

A cruise control switch includes commands, such as ON, OFF, RESUME, SET/ACCEL, and COAST. Drivers can easily find them on the steering wheel or the windshield wiper and set them accordingly. With the SET/ACCEL knob, one can set the car speed. CCS will stop working once the driver hits the brake.

As of today, the number of vehicles on the road is higher than ever. Hence, traditional cruise control is unable to provide the best performance while there is a rise in the popularity of adaptive cruise control.

Reasons Why Cruise Control Not Working

There can be several reasons why cruise control doesn’t work, subject to the system design. Check out these parts to see if any of these are responsible for the issue.

Brake Light Switch

There is a connection between cruise controls and the brake. Cruise controls of some vehicles will stop working if the car is unable to detect the brake light switch.

Brake Lights

In many vehicles, cruise control stops working as soon as the brake light is on. LED brake light conversion and similar lighting might send a false alarm to the CCS that the brake light is on and thus stopping the functioning of cruise control.

Fuses and Relays

Fuses and relays work to protect the actuator circuit of cruise control. Hence, a blown fuse or faulty relay will send a negative signal to the cruise control, and it will stop working.


Usually, the cruise control switch is on the steering wheel. A broken spiral cable may not support connection with the CCS and hence, cruise control not working in the car.

Control Switch

Worn out internal contacts do not allow the cruise control switch to contact the CCS. As a result, cruise control might stop responding to the accelerator, or it might stop working.


Car Engine Light

In contemporary car models that have ETCS, an engine or transmission problem may also lead to the disabling of cruise control.

Vacuum Leak

When it comes to cruise control operation, any older models use vacuum actuators to regulate the throttle body. If there is a crack or a leak in the hose or tube, the system will not work. A leak in the vacuum will cause the same issue.

Vehicle Speed Sensor

Every vehicle comes with multiple vehicle speed sensors (VSS). The CCS makes use of VSS feed that is coming from the ECM, transmission, or instrument cluster. When there is a loss of signal, the CCS can’t detect vehicle speed, disabling cruise control.

Electrical Problems

Cruise control systems consist of electrical or electronic components. When there is any problem source voltage, wiring harnesses, and connectors or any of these is loose, the disabled system will be the consequence.


When there is a faulty cruise control, it will not respond to the “cancel” command. Because it involves risk, users must fix the faulty CCS immediately after diagnosing the cause. Until then, one must stay away from using the cruise control. When cruise control not working, ask a mechanic to inspect and identify the problems and to know how to fix cruise control.