2020 Mercedes-Benz SL550 Cruise Control Isn't Working

Fixing Cruise Control Issues in the 2020 Mercedes-Benz SL550

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Reviewed by
Devin Cabugcal
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 2020 Mercedes-Benz SL550 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 2020 Mercedes-Benz SL550 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 initial diagnostic steps to troubleshoot the non-functional cruise control in a 2020 Mercedes-Benz SL550?

When troubleshooting a non-functional cruise control in your 2020 Mercedes-Benz SL550, it's essential to adopt a systematic diagnostic approach. Start by checking the cruise control fuse, as a blown or damaged fuse can often be the simplest issue to resolve. Next, inspect the cruise control switch to ensure it is operating correctly; a malfunctioning switch can prevent the system from engaging. Following this, verify the condition of the cruise control module, as any faults here could disrupt functionality. Additionally, examine the vehicle's speed sensors, which are critical for the cruise control system to function properly, as they provide necessary data about the vehicle's speed. Finally, scanning the onboard computer system for error codes can reveal underlying issues that may not be immediately apparent. By following these steps in order, you can effectively diagnose and address the problem with your cruise control system.

What are the common problems that could cause the cruise control to stop working in a 2020 Mercedes-Benz SL550?

When the cruise control in your 2020 Mercedes-Benz SL550 ceases to function, it can be frustrating, but understanding the common problems can help you diagnose the issue effectively. One of the primary culprits is a faulty speed sensor, which is crucial for the cruise control system to accurately gauge your vehicle's speed. If this sensor malfunctions, the system may fail to engage or maintain the desired speed. Another frequent issue arises from the brake light switch; if this switch is defective, it may not signal the cruise control system to disengage when the brake pedal is pressed, leading to operational failures. Additionally, a malfunctioning throttle actuator can hinder the system's ability to control the engine's throttle, impacting speed maintenance. Electrical problems, such as blown fuses or wiring issues, can also disrupt the cruise control's functionality, as can software glitches within the vehicle's control module that may require updates or resets. By identifying these potential problems, you can take the necessary steps to troubleshoot and restore your cruise control system to working order.

How urgent is it to repair the non-functioning cruise control on a 2020 Mercedes-Benz SL550?

Repairing the non-functioning cruise control on your 2020 Mercedes-Benz SL550 should be prioritized due to its implications for safety, convenience, and the vehicle's resale value. While it may not seem as urgent as other mechanical issues, the absence of cruise control can lead to increased driver fatigue and distraction, particularly on long drives where maintaining a consistent speed is crucial. This feature not only enhances comfort by allowing the driver to relax but also plays a role in overall road safety. Furthermore, neglecting this repair could negatively impact the vehicle's resale value, as potential buyers may view a malfunctioning cruise control system as a significant drawback. Therefore, addressing this issue promptly is advisable to ensure a safer driving experience, enhance comfort, and protect your investment in the vehicle.

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2020 Mercedes-Benz SL550 Cruise Control Issues & Repairs