2005 Mercedes-Benz ML350 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your 2005 Mercedes-Benz ML350 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 ML350 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 ML350 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 steps to diagnose the cruise control issue in a 2005 Mercedes-Benz ML350?

To effectively diagnose a cruise control issue in a 2005 Mercedes-Benz ML350, it's essential to adopt a systematic approach that begins with the simplest potential problems before moving on 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 issues. Utilizing a diagnostic scanner to check for error codes from the vehicle's onboard computer can provide valuable insights into any underlying problems. Additionally, verify the functionality of the speed sensors, as they are critical for the cruise control system to operate correctly. Don't overlook the brake light switch; a malfunction here can prevent the cruise control from engaging altogether. Finally, test the cruise control module to confirm it is sending the appropriate signals. By following this structured diagnostic approach, you can efficiently identify and address the root cause of cruise control issues in your vehicle.

What are the common problems that could cause the cruise control to stop working in a 2005 Mercedes-Benz ML350?

When dealing with cruise control issues in a 2005 Mercedes-Benz ML350, it's essential to understand the common problems that may arise. One frequent culprit is a faulty brake light switch, which can prevent the cruise control from engaging by failing to signal when the brake pedal is pressed. Additionally, speed sensor issues can disrupt the system's ability to maintain a constant speed, leading to erratic behavior. Vacuum leaks in the engine can also impact the cruise control's functionality, causing it to disengage unexpectedly. Another potential issue is a defective cruise control module, which can directly affect the system's operation. Lastly, electrical problems, such as blown fuses or wiring issues, can interrupt the cruise control function. By identifying these common problems, DIYers can take the first steps toward diagnosing and potentially resolving the cruise control malfunction in their vehicle.

How urgent is it to repair the non-functioning cruise control in a 2005 Mercedes-Benz ML350?

Repairing the non-functioning cruise control in a 2005 Mercedes-Benz ML350 is an urgent matter that should not be overlooked. The absence of this feature can significantly compromise safety, as it requires the driver to maintain constant speed manually, increasing the risk of fatigue and distraction during long drives. Additionally, a functioning cruise control system enhances driving comfort, allowing for a more relaxed experience on highways. Beyond immediate safety and comfort, neglecting this repair can adversely affect the vehicle's resale value; prospective buyers often seek vehicles with fully operational features. Furthermore, in certain jurisdictions, driving with a malfunctioning cruise control system may violate road safety regulations, potentially leading to fines or penalties. Therefore, addressing this issue promptly is crucial for ensuring a safe, comfortable, and legally compliant driving experience.

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2005 Mercedes-Benz ML350 Cruise Control Issues & Repairs