2005 Mercedes-Benz C320 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your 2005 Mercedes-Benz C320 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
0%
25% chance it's the
Control Module
0%
25% chance it's the
Throttle
0%
20% chance it's
Something else
The most common reasons a 2005 Mercedes-Benz C320 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 2005 Mercedes-Benz C320 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.

What are the steps to diagnose the cruise control issue in a 2005 Mercedes-Benz C320?

When diagnosing a cruise control issue in a 2005 Mercedes-Benz C320, it's essential to adopt a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Start by examining the system for any defective components or sensors, as these are often the culprits behind cruise control malfunctions. Next, inspect the instrument cluster, particularly the speedometer assembly, for visible issues such as dry solder joints, which can disrupt the cruise control functionality. If you identify a dry solder joint in the cruise control connector pin, re-soldering it may resolve the problem. By following this methodical diagnostic approach, you can effectively troubleshoot and potentially fix the cruise control system in your vehicle, ensuring a smoother driving experience.

What are the common problems that could cause the cruise control to stop working in a 2005 Mercedes-Benz C320?

When addressing cruise control issues in a 2005 Mercedes-Benz C320, it's crucial to recognize the common problems that may hinder its performance. A primary concern is the brake light switch; if this component is faulty, it can prevent the cruise control from engaging, as the system is designed to deactivate when the brake pedal is pressed. Additionally, issues with the speed sensor can lead to inaccurate speed readings, which are essential for the cruise control to function properly. Vacuum leaks are another potential problem, as they can disrupt the system's ability to maintain a consistent speed. Furthermore, a defective cruise control module can be a significant factor in the system's failure, given its role in controlling the cruise function. Lastly, electrical problems, such as blown fuses or damaged wiring, can also impede the cruise control's operation. By systematically diagnosing these common issues, DIYers can effectively troubleshoot and restore the cruise control functionality in their Mercedes-Benz C320.

How urgent is it to repair the non-functioning cruise control in a 2005 Mercedes-Benz C320?

When evaluating the urgency of repairing the non-functioning cruise control in your 2005 Mercedes-Benz C320, it's essential to recognize the implications of neglecting this issue. While it may not seem like an immediate emergency, the absence of cruise control can significantly impact your driving experience and safety. Without this feature, maintaining a consistent speed becomes more challenging, which can lead to increased driver fatigue and distraction, especially on long trips. This not only diminishes comfort but also raises safety concerns, as a fatigued driver is more prone to errors. Furthermore, addressing the cruise control issue promptly can help preserve the resale value of your vehicle. A well-maintained car is more appealing to potential buyers, and minor repairs like this can make a substantial difference in overall vehicle condition. Therefore, while the repair may not be urgent, it is wise to prioritize it to ensure a safer, more comfortable driving experience and to protect your investment in the long run.

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