2008 Mercedes-Benz R350 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your 2008 Mercedes-Benz R350 and How to Fix Them

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Reviewed by

Devin Cabugcal

Written by RepairPal Car Genius

Updated January 14, 2025

30% chance it's the

Sensor

25% chance it's the

Control Module

25% chance it's the

Throttle

20% chance it's

Something else

The most common reasons a 2008 Mercedes-Benz R350 cruise control isn't working are failed control module, sensor or switch issues, or throttle actuation problems.

Sensor: A faulty sensor can lead to incorrect readings, causing issues with engine performance or triggering warning lights on the dashboard.
Control Module: A faulty control module can result in 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 acceleration and poor engine 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.

What are the best Mercedes-Benz repair shops?

RepairPal Certified shops can diagnose and repair your 2008 Mercedes-Benz R350 electronics and electrical issues. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.

How much does it cost to fix a 2008 Mercedes-Benz R350 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 cruise control issue in a 2008 Mercedes-Benz R350?

To effectively diagnose the cruise control issue in a 2008 Mercedes-Benz R350, start with a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Begin by utilizing a Mercedes-Benz capable scanner to retrieve any error codes, as this will provide insight into the vehicle's electronic systems and highlight potential issues. Next, investigate common culprits such as a malfunctioning control module, faulty sensors, or issues with the throttle actuation. Pay particular attention to the brake pedal switch, as a defect here can disrupt the cruise control functionality. Additionally, test the actuator for resistance using a voltmeter, since low resistance can indicate a problem that may damage the controller. Finally, don’t overlook the possibility of blown fuses, which can interrupt power to critical components of the cruise control system. By following this structured diagnostic approach, you can efficiently identify and address the root cause of the cruise control malfunction in your vehicle.

How urgent is it to address the malfunctioning cruise control in a 2008 Mercedes-Benz R350?

When it comes to a malfunctioning cruise control system in a 2008 Mercedes-Benz R350, the urgency of addressing the issue cannot be overstated. While it may not seem like an immediate emergency, neglecting the problem can lead to significant inconveniences, especially during long drives where cruise control is essential for comfort and efficiency. Moreover, a malfunctioning cruise control system may be indicative of deeper issues within the vehicle, such as problems with the throttle or control module, which could compromise overall performance and safety. Common culprits behind cruise control failures include faulty switches, blown fuses, and electrical malfunctions, all of which can disrupt the functionality of the system and potentially trigger warning lights. Therefore, it is crucial to diagnose and repair these issues promptly to avoid further complications and ensure a safe driving experience. Addressing cruise control malfunctions not only enhances convenience but also safeguards against potential risks associated with underlying vehicle problems.

Related 2008 Mercedes-Benz R350 Problems

Read about related problems experienced by other Mercedes-Benz R350 drivers like you.

Mercedes-Benz R350 locked in park mode despite functional brake lights and new batteries

Some Mercedes-Benz R350 owners report experiencing issues with their vehicle being locked in park mode, despite having functional brake lights and new batteries. These problems may stem from a malfunctioning brake light switch that is not detected by the system, even when the lights are operational. Additionally, some owners face challenges related to the shifter assembly, which may prevent the car from shifting out of park mode. Another potential cause is the absence of a CAN signal from the ESP or steering column switch/control module, hindering the release from the park position. To address these concerns, owners are advised to inspect the brake light switch for proper functionality, examine the shifter assembly for visible issues, and diagnose the CAN signal to ensure effective communication within the system. If these measures do not resolve the problem, consulting a certified mechanic or dealership for further diagnosis and repair is recommended.

1 model year affected

Avg Mileage: 190,000

2 others reported problem

1 comment

Mitsubishi Diamante cruise control malfunction after drive line obstruction removal

Some Mitsubishi Diamante owners report experiencing cruise control malfunctions after removing a drive line obstruction, often linked to issues with the control module, sensor, or switch. These problems may stem from failed components that prevent the cruise control system from engaging or holding speed, despite power being available to the dash and fuse. Additionally, throttle actuation issues, such as a faulty throttle position sensor, can lead to the engine's computer overcompensating with fuel, which may result in black exhaust from the tailpipe. Owners are advised to thoroughly troubleshoot the cruise control system and inspect key components like the control module, sensor, and throttle to identify any damage or malfunction caused during the obstruction removal process.

4 model years affected

Avg Mileage: 1162,250

5 others reported problem

1 comment

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