2003 Mercedes-Benz SLK320 Cruise Control Isn't Working

Fixing Cruise Control Issues in Your 2003 Mercedes-Benz SLK320

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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 2003 Mercedes-Benz SLK320 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 2003 Mercedes-Benz SLK320 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 steps to diagnose the non-functioning cruise control in a 2003 Mercedes-Benz SLK320?

When diagnosing the non-functioning cruise control in a 2003 Mercedes-Benz SLK320, it's crucial to follow a methodical diagnostic approach that emphasizes simpler checks before tackling more complex issues. Begin by assessing the cruise control module, as it is often a primary source of malfunction; ensure it is functioning correctly and free from faults. Next, inspect the associated sensors and switches, as any issues here can disrupt the cruise control's operation. It's also important to examine the throttle actuation, ensuring it operates smoothly, as this is essential for the cruise control to engage properly. If the ABS and ETS warning lights are illuminated, this may indicate a problem with the brake light switch, which is critical for cruise control functionality. Finally, check the connectors for any signs of damage or poor connections, as these can lead to significant issues. By systematically addressing these components, you can effectively diagnose and resolve the problems affecting your vehicle's cruise control system.

What are the common problems that could cause the cruise control to stop working in a 2003 Mercedes-Benz SLK320?

When troubleshooting the cruise control system in a 2003 Mercedes-Benz SLK320, it's essential to consider several common problems that could be at play. One of the primary culprits is a faulty brake light switch, which can prevent the cruise control from engaging if it fails to signal that the brake pedal has been pressed. Additionally, a defective cruise control module may hinder the system's overall functionality, leading to complete failure. Another issue to investigate is the presence of vacuum leaks within the cruise control system, as these can disrupt its ability to maintain speed effectively. Furthermore, a malfunctioning speed sensor can impact the system's performance, making it difficult for the cruise control to operate correctly. Lastly, electrical issues, such as blown fuses or wiring problems, can also contribute to the cruise control's failure. By systematically checking these components, DIYers can identify and address the root cause of the cruise control malfunction, potentially restoring its functionality without the need for professional assistance.

How urgent is it to repair the non-functioning cruise control in a 2003 Mercedes-Benz SLK320?

Repairing the non-functioning cruise control in your 2003 Mercedes-Benz SLK320 is not just a matter of convenience; it is a pressing safety concern that should be addressed without delay. A malfunctioning cruise control system can lead to increased driver fatigue, especially on long trips, as it forces the driver to constantly adjust their speed. This can distract from the road and increase the risk of accidents. Moreover, neglecting this issue may indicate deeper problems within the vehicle's electronic systems, which could compromise overall performance and safety. Additionally, a properly functioning cruise control system can enhance fuel efficiency by maintaining a steady speed, ultimately saving you money at the pump. Therefore, addressing the cruise control malfunction promptly is essential for ensuring a safe, comfortable, and efficient driving experience.

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2003 Mercedes-Benz SLK320 Cruise Control Issues & Repairs