Mercedes-Benz CLS400 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your Mercedes-Benz CLS400 and How to Fix Them

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Reviewed by
Aisha
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 CLS400 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 CLS400 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 CLS400

When troubleshooting cruise control issues in your Mercedes-Benz CLS400, it's essential to adopt a systematic diagnostic approach. Start by checking the simplest components, such as the fuse and brake light functionality, as these can often be the culprits behind a non-responsive system. Next, inspect the brake light switch, which can malfunction even if the brake lights appear to be working correctly. If these initial checks do not resolve the issue, move on to examining the throttle and control module, as problems in these areas are common. Additionally, consider the speed sensors, especially if you lack advanced diagnostic tools; they can provide valuable insights into the system's performance. If your cruise control operates intermittently, this may indicate deeper electronic or mechanical issues that require further investigation. While DIY troubleshooting can be effective, if you find that these steps do not lead to a solution, it may be wise to consult a professional service team for a comprehensive diagnosis and repair.

What Could Cause Cruise Control Malfunctions in a Mercedes-Benz CLS400?

When addressing cruise control malfunctions in a Mercedes-Benz CLS400, it's important to recognize the various common problems that could be at play. A defective brake pedal switch is often a primary issue, as it can cause the cruise control to disengage unexpectedly. Additionally, a dead battery may lead to power disruptions affecting the cruise control system. The ABS wheel speed sensor is another critical component; if it fails, it can trigger warning lights and interfere with cruise control functionality. Checking for blown fuses is essential, as these can disrupt the power supply to the system. Ensuring that the brake pedal sensor is working correctly is also vital for proper engagement of cruise control. Moreover, underlying engine or transmission issues can cause the cruise control to deactivate, particularly if the engine light is on. To effectively diagnose the problem, utilizing a diagnostic scanner to retrieve fault codes, along with a comprehensive visual inspection of the cruise control components, is advisable. Repairing any damaged wiring and replacing faulty components, such as switches or modules, can help restore the system's functionality. By systematically addressing these potential issues, you can effectively troubleshoot and resolve cruise control problems in your CLS400.

Why is the Cruise Control Not Working in a Mercedes-Benz CLS400?

When the cruise control in your Mercedes-Benz CLS400 malfunctions, it’s crucial to address the issue promptly to ensure your safety on the road. A defective brake pedal switch is a common culprit, as it directly impacts the cruise control system's ability to function. Ignoring this problem could lead to unexpected braking or acceleration, posing a significant risk during highway driving. Additionally, a dead battery or a faulty ABS wheel speed sensor can trigger warning lights, indicating that the cruise control system may be compromised. If left unchecked, these issues could escalate, potentially leading to costly repairs or even dangerous driving conditions. Furthermore, problems with the throttle control system or blown fuses can also disrupt cruise control functionality, making it essential to diagnose and resolve these issues quickly. In some cases, external factors like weather conditions can affect the system, but relying on professional inspection is the best course of action to ensure your vehicle remains safe and reliable. Prioritizing these repairs not only enhances your driving experience but also safeguards your vehicle's overall performance.

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