2004 Mercedes-Benz E320 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your 2004 Mercedes-Benz E320 and How to Fix Them

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Reviewed by
Bo Fader
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 2004 Mercedes-Benz E320 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 2004 Mercedes-Benz E320 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.

A faulty cruise control module will simply result in deactivation of cruise control settings. This is because a detected error in the cruise control system could lead to hazardous driving conditions, so the module will be disabled, and the cruise control system warning light will be displayed. This will be a different message depending on make and model, and a warning light or message may be displayed on the driver instrument cluster.

What are the initial diagnostic steps to troubleshoot the non-functioning cruise control in a 2004 Mercedes-Benz E320?

When troubleshooting the non-functioning cruise control in a 2004 Mercedes-Benz E320, it's essential to adopt a systematic diagnostic approach. Start by checking the cruise control fuse, as a blown or damaged fuse can easily disrupt the system's operation. Next, inspect the cruise control switch located on the steering wheel to ensure it is functioning correctly; a malfunctioning switch can prevent the system from engaging. It's also crucial to verify that the brake lights are operational, as a faulty brake light switch can inadvertently disable the cruise control. Additionally, examine the vehicle speed sensor, which plays a vital role in relaying accurate speed information to the cruise control module. Finally, scanning the vehicle's onboard computer for any error codes can provide valuable insights into underlying issues affecting the cruise control system. By following these steps, you can effectively narrow down the potential causes of the problem and take appropriate action to restore functionality.

What are the common problems that could cause the cruise control to stop working in a 2004 Mercedes-Benz E320?

When troubleshooting the cruise control system in a 2004 Mercedes-Benz E320, it's essential to understand the common problems that may lead to its failure. One of the primary culprits is a faulty brake light switch, which can prevent the cruise control from engaging since the system is designed to disengage when the brake pedal is pressed. Additionally, issues with the speed sensor can disrupt the system's ability to maintain speed, as it relies on accurate readings to function correctly. Another potential issue is vacuum leaks within the cruise control system, which can significantly impair its operation. Furthermore, a defective cruise control module may also be responsible for the malfunction, as it is the central component that controls the system. Lastly, electrical problems, such as blown fuses or wiring issues, can hinder the cruise control's functionality. By identifying and addressing these common issues, you can effectively troubleshoot and potentially restore the cruise control system in your vehicle.

How urgent is it to repair the non-functioning cruise control in a 2004 Mercedes-Benz E320?

When evaluating the urgency of repairing the non-functioning cruise control in your 2004 Mercedes-Benz E320, it's essential to consider how often you utilize this feature and the driving conditions you typically encounter. If you frequently embark on long highway drives where cruise control enhances comfort and reduces fatigue, addressing the malfunction sooner can significantly improve your driving experience. Additionally, if the absence of cruise control detracts from your overall comfort or convenience, it may warrant prompt attention. While the issue does not pose immediate safety risks, neglecting it could lead to further complications or a more costly repair down the line. Therefore, if cruise control is a vital aspect of your driving routine, prioritizing its repair can lead to a more enjoyable and stress-free journey.

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