2018 Mercedes-Benz GLS450 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your 2018 Mercedes-Benz GLS450 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
0%
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 2018 Mercedes-Benz GLS450 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 2018 Mercedes-Benz GLS450 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.

What are the initial diagnostic steps to take when the cruise control isn't working on a 2018 Mercedes-Benz GLS450?

When faced with a malfunctioning cruise control system in a 2018 Mercedes-Benz GLS450, it's crucial to adopt a systematic diagnostic approach. Start by checking the cruise control fuse, as a blown or damaged fuse can disrupt the entire system. Next, verify the speed sensors, which are vital for relaying the vehicle's speed to the cruise control; any faults here can lead to operational issues. Additionally, examine the brake pedal switch, since a malfunctioning switch can prevent the cruise control from engaging altogether. Don't overlook the steering wheel controls; ensure that the cruise control buttons are functioning properly, as any issues here can directly affect system performance. Finally, using a diagnostic scanner to check for error codes can provide valuable insights into specific problems that may be affecting the cruise control system. By following these steps, you can effectively diagnose and address the underlying issues with your cruise control, potentially saving time and money on repairs.

What are the common problems that could cause the cruise control to stop working in a 2018 Mercedes-Benz GLS450?

When troubleshooting the cruise control system in a 2018 Mercedes-Benz GLS450, it's essential to understand the common problems that may lead to its malfunction. One prevalent issue is a faulty speed sensor, which can disrupt the system's ability to accurately gauge the vehicle's speed, preventing it from engaging or maintaining the desired speed. Additionally, the brake light switch plays a crucial role; if this switch is malfunctioning, it may fail to send the necessary signal to disengage the cruise control when the brake pedal is pressed. Another potential culprit is the throttle actuator, which controls the engine's throttle opening; any malfunction here can hinder the system's capacity to maintain speed. Furthermore, a defective cruise control module itself can lead to complete system failure, as it is responsible for regulating speed when cruise control is activated. Lastly, electrical issues such as wiring problems or blown fuses can also impede the cruise control's functionality. By identifying and addressing these common issues, DIY enthusiasts can effectively diagnose and potentially resolve cruise control problems in their vehicle.

How urgent is it to address the non-functioning cruise control in a 2018 Mercedes-Benz GLS450?

When it comes to the non-functioning cruise control in a 2018 Mercedes-Benz GLS450, understanding the urgency of the situation is crucial for any DIY enthusiast. While this issue may not seem as critical as a malfunctioning brake system or engine failure, it still warrants prompt attention. A malfunctioning cruise control can lead to increased driver fatigue, especially during long trips, as it removes the convenience of maintaining a steady speed without constant acceleration. Moreover, neglecting this problem could result in further complications within the vehicle's electronic systems, potentially leading to more extensive and costly repairs in the future. Therefore, while it may not pose an immediate safety risk, addressing the cruise control issue is essential for ensuring the vehicle's overall performance and comfort. Taking the time to diagnose and repair this feature not only enhances your driving experience but also helps maintain the integrity of your vehicle's systems, making it a worthwhile endeavor for any DIY mechanic.

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2018 Mercedes-Benz GLS450 Cruise Control Issues & Solutions