Mercedes-Benz C350 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your Mercedes-Benz C350 and How to Fix Them

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
30% chance it's the
Sensor
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25% chance it's the
Control Module
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25% chance it's the
Throttle
0%
20% chance it's
Something else
The most common reasons a Mercedes-Benz C350 cruise control isn't working are failed control module, sensor or switch issues, or throttle actuation problems.
  • Sensor: A faulty or malfunctioning sensor can lead to incorrect readings, causing issues with engine performance or other systems relying on accurate data.
  • Control Module: A faulty control module can lead to erratic vehicle behavior or failure of various electronic systems due to improper signal processing.
  • Throttle: A faulty throttle body or a defective accelerator pedal position sensor may be causing inconsistent throttle response.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a Mercedes-Benz C350 cruise control isn't working?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

In the event that a wheel speed sensor fails, the ABS, traction control system (TCS) and manufacturer specific stability control system lights will illuminate, informing the driver that the systems are disabled. The vehicle will be more prone to tire slip, and normal driving patterns may need to be adjusted to correct for the loss of computer control. On older vehicle's, the speedometer can be affected, causing illumination of the check engine light as well.

Troubleshooting Cruise Control Issues in a Mercedes-Benz C350

When troubleshooting cruise control issues in your Mercedes-Benz C350, start with the basics to identify the problem efficiently. Begin by checking the fuses related to the cruise control system, as a blown fuse can often be the simplest fix. Next, inspect the brake light switch; even if your brake lights are functioning, a faulty switch can disrupt the cruise control operation. If these components are in good condition, move on to the ABS sensors, as a failure in any of the wheel speed sensors can disable the cruise control system. Additionally, examine the multi-function relay located behind the fuse box, as it plays a crucial role in the system's functionality. If these checks do not resolve the issue, consider using the MB diagnostic system, Star, to read any diagnostic codes that may point to more complex problems, such as throttle control system issues or defective components. By following this structured approach, you can effectively diagnose and potentially resolve cruise control malfunctions in your vehicle.

What Could Cause the Cruise Control to Malfunction in a Mercedes-Benz C350?

When dealing with cruise control malfunctions in a Mercedes-Benz C350, it's essential to understand the common problems that may arise. One frequent issue is a failed control module, sensor, or switch, which can disrupt the system's functionality. Additionally, throttle actuation problems can prevent the cruise control from engaging properly. It's also worth considering the possibility of improper tire placement, particularly if you've recently had tire work done; incorrect positioning of the wheels can lead to unexpected cruise control behavior. A faulty wheel sensor may also be at fault, especially if no other diagnostic issues are apparent. Lastly, don't overlook the cruise control button itself; debris or dirt can accumulate and hinder its operation. By examining these potential causes, you can effectively troubleshoot and resolve cruise control issues in your Mercedes-Benz C350, ensuring a smoother driving experience.

Why is the Cruise Control Not Working in a Mercedes-Benz C350?

When the cruise control in your Mercedes-Benz C350 fails, it’s crucial to address the issue promptly, as neglecting it can lead to safety risks and further vehicle complications. Common culprits include a malfunctioning control module, faulty sensors, or switch issues, which can disrupt the cruise control system's functionality. Additionally, problems with throttle actuation or ABS sensor failures can also impede cruise control operation, as these systems are interconnected. A damaged speed sensor is another critical factor; it plays a vital role in maintaining your vehicle's speed, and if it fails, the cruise control may disengage unexpectedly, posing a hazard on the road. Furthermore, ensure that the cruise control is properly selected, as an illuminated LIM indicator lamp may indicate that the Variable Speedtronic is active, preventing cruise control from engaging. Addressing these issues not only restores the convenience of cruise control but also ensures your safety and the overall integrity of your vehicle.

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