Mercedes-Benz S350 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your Mercedes-Benz S350 and How to Fix Them

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Reviewed by
Bo Fader
Written by RepairPal Car Genius
Updated January 14, 2025
0%
30% chance it's the
Sensor
0%
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 S350 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 S350 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.

The cruise control switch can cause complete failure of the cruise control feature, but in a lucky scenario only partial functionality will be lost. This means that the cruise control may come on, but that it will not increase in speed automatically, or the cancel button does not work leading the driver to cancel cruise control with the foot brake. In some vehicles, the cruise control light may illuminate, or a warning message may be displayed due to lack of functionality.

Troubleshooting Cruise Control Issues in a Mercedes-Benz S350

When troubleshooting cruise control issues in your Mercedes-Benz S350, it's essential to adopt a systematic diagnostic approach. Begin by checking the simplest components, such as the brake light switch, which can often be the culprit behind cruise control malfunctions. If the brake lights are not functioning correctly, it may prevent the cruise control from engaging. Next, observe whether the cruise control operates intermittently; this could indicate electronic or mechanical issues that require further investigation. Pay attention to any warning messages displayed on the instrument cluster, as these can provide critical clues about underlying problems. If you encounter persistent issues or if the system remains inoperative despite your efforts, consider consulting online resources or guides created by fellow Mercedes-Benz owners, as they can offer valuable insights and troubleshooting tips. While DIY troubleshooting can be effective, don't hesitate to seek professional assistance if the problem proves too complex, ensuring that your vehicle is diagnosed and repaired accurately.

What Could Cause the Cruise Control to Malfunction in a Mercedes-Benz S350?

When dealing with cruise control malfunctions in a Mercedes-Benz S350, it's crucial to understand the common problems that could be causing the issue. One of the primary culprits is a defective brake pedal switch, which can prevent the cruise control from engaging properly. Additionally, a dead battery may disrupt the electrical systems, leading to cruise control failures. Another significant factor is the ABS wheel speed sensor; if this sensor is faulty, it can send incorrect data to the cruise control system, resulting in erratic behavior. Furthermore, issues with the cruise control switch or module itself may necessitate replacement to restore functionality. Other potential contributors include slipping tires, erratic acceleration data, or malfunctioning wheel speed sensors, all of which can interfere with the cruise control's operation. To effectively address the problem, a thorough diagnosis is essential to pinpoint the exact cause and implement the necessary repairs.

Why is the Cruise Control Not Working in a Mercedes-Benz S350?

When the cruise control in your Mercedes-Benz S350 fails, it’s crucial to address the issue promptly, as neglecting it can lead to safety hazards on the road. A malfunctioning cruise control system can distract you from driving, increasing the risk of accidents, especially during long trips where you rely on this feature for comfort and convenience. Common culprits such as a defective brake pedal switch, dead battery, or faulty ABS wheel speed sensor can disrupt the system's functionality. Additionally, issues like a blown fuse or problems with the throttle control system may exacerbate the situation. Ignoring these symptoms not only compromises your safety but can also lead to more significant mechanical problems down the line, resulting in costly repairs. Therefore, if you notice your cruise control is not working, it’s advisable to conduct a thorough inspection or consult a professional to ensure your vehicle remains safe and reliable on the road.

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Mercedes-Benz S350 Cruise Control Issues & Repair Costs