2019 Mercedes-Benz SL450 Cruise Control Isn't Working

Fixing Cruise Control Issues in Your 2019 Mercedes-Benz SL450

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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 2019 Mercedes-Benz SL450 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 2019 Mercedes-Benz SL450 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 steps should I take to diagnose the cruise control issue in my 2019 Mercedes-Benz SL450?

When diagnosing a cruise control issue in your 2019 Mercedes-Benz SL450, it's essential to adopt a systematic approach that begins with the simplest solutions before progressing to more complex diagnostics. Start by checking the cruise control fuse, as a blown fuse can easily disrupt the system's functionality. Next, inspect the cruise control buttons on the steering wheel to ensure they are operational, since faulty buttons can lead to engagement problems. Utilizing an OBD-II scanner to scan for error codes is a crucial step, as these codes can pinpoint specific issues within the cruise control system. Additionally, verify the functionality of the speed sensors, which are vital for the cruise control to operate correctly. It's also important to examine the wiring connections associated with the cruise control system for any signs of damage or loose connections, as these can impede performance. Finally, test the cruise control module itself to confirm it is functioning properly. If these steps do not resolve the issue, seeking assistance from a professional mechanic or an authorized Mercedes-Benz service center is advisable for a comprehensive diagnosis and repair. By following this structured diagnostic approach, you can effectively identify and address the cruise control problem in your vehicle.

What are the common problems that could cause the cruise control to stop working in a 2019 Mercedes-Benz SL450?

When the cruise control in your 2019 Mercedes-Benz SL450 stops functioning, 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 the vehicle's speed. If this sensor malfunctions, the system may fail to engage or maintain the desired speed. Another potential issue is a defective brake light switch; since this switch is designed to disengage cruise control when the brakes are applied, any malfunction can disrupt the system's operation. Additionally, problems with the throttle actuator can hinder the cruise control's ability to adjust the throttle position, further complicating its functionality. Electrical issues, such as blown fuses or wiring problems, can also impact the cruise control system, leading to unexpected failures. Lastly, a malfunctioning cruise control module may prevent the system from processing necessary signals, rendering it inoperative. By identifying these common problems, you can take the first steps toward troubleshooting and potentially resolving the cruise control issues in your vehicle.

How urgent is it to address the non-functioning cruise control in a 2019 Mercedes-Benz SL450?

When faced with a non-functioning cruise control in a 2019 Mercedes-Benz SL450, it is crucial to recognize the urgency of the situation. Cruise control not only enhances driving comfort by maintaining a steady speed, but it also plays a significant role in overall vehicle performance and safety. A malfunctioning system could signal deeper issues within the vehicle's electronic or mechanical components, which, if left unaddressed, may lead to more severe problems and costly repairs down the line. For DIY enthusiasts, it is essential to understand that while troubleshooting may seem straightforward, the underlying causes can be complex and may require professional diagnostics. Ignoring the symptoms of a faulty cruise control system can result in safety hazards, such as unexpected acceleration or difficulty maintaining speed, which could endanger both the driver and others on the road. Therefore, it is advisable to prioritize the diagnosis and repair of the cruise control system to ensure the vehicle operates safely and efficiently.

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2019 Mercedes-Benz SL450 Cruise Control Issues & Repairs