Freightliner Cruise Control Not Working [7 Easy Fixes]

A heavy-duty truck like a Freightliner has a massive control panel. If anything goes wrong in the system, it may cost you an expensive repair.

Recently, I checked in with my friend, who was having trouble turning on cruise control on his aftermarket freightliner. We figured out the following reasons and fixes to make it work.

If your Freightliner cruise control is not working, follow along to find the reasons and solutions to the problem.

Why My Freightliner Cruise Control Not Working

Freightliner Cruise Control Not Working

Here are the following reasons that cause your Freightliner Cascadia, Columbia, Coronado, or others from 2011 and above.

1. Faulty speed sensor

You need to check the speed sensor in the Freightliner first. It’s important because the speed sensor engages the system at the speed you set on a Freightliner. If that is faulty, unfortunately, the cruise control system will not turn on.

2. Wiring Harness

Due to the rough road conditions, the harness that encloses the wires in one place can be damaged. In a Freightliner truck, you will see many harnesses behind the dash. A faulty wiring harness connected to the cruise control will not let you run the truck on cruise control mode.

3. ECM

The engine control module in your Freightliner controls all the functions, including sensors, fuel injectors, etc., and failing cruise control, which will initiate the ‘Check engine light’ on the dash. 

If you trust a mechanic who can handle the ECM problem, go to them to investigate the issue.

4. Faulty spiral cable/ Clockspring

The steering column has all the buttons connected to the cruise control system. The misaligned clock spring would interfere with the cruise control mechanism.

5. Faulty Air switch 

The air switches are present under the dash. These are connected to your Freightliner cruise control and idle function. These switches must work perfectly to run the truck on cruise control.

 Check to see if the air switches are working perfectly. You can find their location by reading the manual in the picture below.

6. Brake pedal switches

The brake pedal has a switch that wears out after constant use. So even if it’s not depressed, the faulty switch sets slightly inwards, making the Freightliner cruise control sensors believe that the brake is engaged.

That stops the cruise control. Therefore, you must ensure the brake pedal switch is working perfectly. If not, then replace it.

7. Brake light

You see the brake lights warning on the display of the Freightliner. That does not always mean that the brake is depressed. It typically indicates a low brake fluid or a hydraulic leak. Therefore, check these before you try driving the truck on cruise control.

8. Malfunctioning switches

The cruise control switches on the steering go bad and fail to engage the control system. That is a common fault that occurs in many freight liners.

You can easily replace the damaged switches with new ones to restore the cruise control function.

How to Fix Freightliner Cruise Control Not Working

If you have not solved the problem yet, don’t worry. Here are all the proven fixes to make your Freightliner cruise control work perfectly.

1. Replace Cruise Control Sensor

The cruise control sensor is the most common cause of malfunctioning cruise control. If you don’t know how to replace the sensor, here is the step-by-step guide.

  • The sensor is under the driver’s side of your truck, so you need to access it by lying under your vehicle.
  • The sensor has failed transmission because it is loosely connected or faulty.
  • Detach the sensor and clean it from any dust. 
  • Afterward, put it back in place properly. 
  • Replace the sensor if it is damaged.

2. Change Brake pedal switches.

It’s present under the brake, and you need to disconnect it from the connectors to replace the new one.

Fortunately, it’s an easy and inexpensive fix, so you just need to buy a new brake padel switch. Afterwards, follow these steps.

  • Have some light in your hand and access the brake light switch under the brake padel.
  • Then, remove the connector. You will notice the old one is slightly loose if it’s the reason your cruise control is not working.
  • Connect the new switch with the connector and check your vehicle’s cruise control.

3. Replace the Air Manifold Switch for the Cruise Control

The air manifold switches behind the dash have a few switches connected to various electrical functions in your Freightliner.

If one labeled as the ‘Cruise’ is not working or the other two located above and below the cruise switch are not working, the cruise control will stop working.

Here is how you can change the Air manifold switches.

  • Remove the hood on the right side of the steering.
  • Then, remove the faulty switches labeled in the manual connected to the cruise control.
  • Put the new one and check the cruise control.

4. Replace the Faulty Wiring Harness

The wire harness interrupts the signal transmission if they are faulty. Therefore, you can run a diagnostic test to trace which wire is not working and then ground the wire.

That should restore the cruise control function.

5. Change the Cruise Control Switches

If your Freightliner’s switches do not respond when you press any of them, replace them using the following steps.

  • You need to disassemble the steering wheel assembly to access the switches; therefore, remove the top plastic piece of steering first.
  • Then, remove the bolts on the back side of the steering to completely detach it and disconnect the connectors.
  • Detach the connectors with the cruise control switches and install the new ones.
  • Assemble the steering wheel; the process is the opposite of disassembling.

6. Repair ClockSpring

The spiral cable inside the steering wheel must be replaced if the cruise control is not working. That will not let your Freightliner’s cables connect with the ECM., which means the circuit is incomplete. You must check the clock spring by opening the steering wheel’s bolts.

You may need to replace or reconnect the clock spring to its exact place.

7. Replace Faulty Fuse

The cruise control is connected to the fuse in the fuse box beside the engine hood. A faulty fuse would break the circuit in the Freightliner, and you would have to trace the fuse connected to the cruise control and replace it with a new one.

You can find the Freightliner Cruise Control Fuse Location in the fuse box by reading the user manual of Freightliner.

8. Replace ECM

Watching the ‘Check engine light’ on the dash and not doing anything is dangerous. It is one of the reasons that cruise control stops working. ECM is connected to many electrical functions, including temperature and air-fuel mixture, and regulates cruise control.

If ECM is not working, you need to get the vehicle to a nearby dealership and seek help to replace it.

How Do You Turn On Cruise Control On Freightliner

You can turn the cruise control ‘On’ and ‘Off’ through the switches on the steering wheel. However, there is another switch on the dash, too.

  • Press the ‘Set’ button to turn ‘On’ the cruise control.
  • Afterwards, press the ‘Res’ button to increase the speed and then press ‘Set’ again to fix the speed wherever you want.
  • Also, you can stop the cruise control system by pressing ‘Cancel’ anytime.

Freightliner Cascadia Cruise Control and Engine Brake Not Working?

The wiring harness behind the dash connected to the engine brake, also called Jack brakes, may get damaged, and you need to ground one of the wires connected to the cruise control.

That would restore the function of your Freightliner Cascadia cruise control and engine brake function.

Final Thoughts

If worse comes to worse, I am afraid that you would need to replace the cruise control module, which is expensive.

But do not engage the cruise control if it gets disconnected due to some reason at any point.

Because it is too dangerous to drive in that situation, if you trust a technician regarding the issue, contact them to solve the problem for you.

References

How To Replace The Cruise Control Sensor In Freightliner

Method To Replace Faulty Cruise Control Switches Of A Freightliner

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