Mercedes-Benz SL500 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your Mercedes-Benz SL500 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 SL500 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 SL500 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 SL500

When troubleshooting cruise control issues in a Mercedes-Benz SL500, it's essential to adopt a systematic diagnostic approach. Begin by checking the fuses associated with the cruise control system, as a blown fuse can often be the simplest explanation for malfunction. Next, inspect the brake system, focusing on the brake light and brake switch, since these components play a critical role in the cruise control's operation. If these initial checks do not resolve the issue, consider performing a diagnostic scan to identify any engine-related problems that may be affecting the cruise control functionality. This step is particularly important if a check engine light is illuminated, as it can provide valuable insights into underlying issues. If the problem persists after these assessments, it may be time to consult a professional mechanic for a thorough inspection and repair. By following this structured approach, you can effectively narrow down the potential causes of cruise control malfunctions and take appropriate action to restore its functionality.

What Could Cause the Cruise Control to Malfunction in a Mercedes-Benz SL500?

When troubleshooting cruise control malfunctions in a Mercedes-Benz SL500, it's essential to recognize the common problems that may arise. A defective brake pedal switch is often the primary culprit, as it can prevent the cruise control from engaging or cause it to disengage unexpectedly. Additionally, issues with the throttle control system can disrupt the cruise control's ability to maintain a steady speed, leading to erratic performance. A faulty ABS wheel speed sensor is another potential issue, as it can trigger warning lights and interfere with cruise control functionality. For older models, damaged vacuum lines may also be responsible for malfunctions, as leaks can significantly impact operation. Furthermore, electronic glitches in components such as the control module or sensors can result in erratic behavior or complete failure of the system. Lastly, problems with the ASR system, which integrates with both cruise control and throttle management, can also affect performance. By identifying these common issues, DIY enthusiasts can better diagnose and address cruise control problems in their SL500.

Why is the Cruise Control Not Working in a Mercedes-Benz SL500?

When the cruise control in your Mercedes-Benz SL500 is malfunctioning, it’s crucial to address the issue without delay. Ignoring symptoms such as a faulty ABS sensor or a blown fuse can not only compromise your driving experience but also pose significant safety risks. For instance, if the cruise control system displays a set speed yet fails to maintain it, this could indicate a deeper malfunction that may affect other critical systems like ABS and stability control. Additionally, a defective brake pedal switch or issues with the throttle control can lead to erratic vehicle behavior, increasing the likelihood of accidents. Furthermore, in older models, a broken vacuum line can disrupt the cruise control functionality, leading to potential engine performance issues. Therefore, it is advisable to conduct a thorough inspection of these components and, if necessary, utilize the Mercedes-Benz diagnostic system to pinpoint specific faults. Promptly addressing these concerns not only ensures your safety on the road but also prevents more extensive and costly repairs down the line.

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Mercedes-Benz SL500 Cruise Control Issues & Repair Costs