1998 Audi A6 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your 1998 Audi A6 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
0%
25% chance it's the
Throttle
0%
20% chance it's
Something else
The most common reasons a 1998 Audi A6 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 1998 Audi A6 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.

When the vehicle speed sensor fails or the wiring harness prevents signal transmission, the speedometer is the first thing that will stop functioning properly. This can be an intermittent issue where the speedometer only works occasionally, the speedometer may cease all function, or the speedometer may read erratically or incorrectly. Also, the traction control and anti lock brake warning lights specific to each vehicle may be illuminated, depending on the design of those systems. You may notice the vehicle hesitate to accelerate, cruise control will not function properly, and the vehicle may not shift properly through all of the gears.

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.

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 steps to diagnose the non-functioning cruise control in a 1998 Audi A6?

When faced with a non-functioning cruise control in a 1998 Audi A6, it's important to adopt a systematic diagnostic approach that begins with the simplest solutions. Start by checking the fuse associated with the cruise control system, as a blown fuse is a common and easily fixable issue. Next, inspect the cruise control switch to ensure it is operational; a malfunctioning switch can prevent the system from engaging. The brake pedal switch is another critical component to examine, as it must function correctly to disengage the cruise control when the brakes are applied. Additionally, review the vehicle speed sensor, which is essential for the cruise control to receive accurate speed data. If these initial checks do not resolve the issue, using a diagnostic scanner to scan for error codes can provide deeper insights into potential problems. Finally, inspect the wiring and connections for any signs of damage or corrosion, as faulty wiring can significantly impact the cruise control's functionality. By following these steps, you can effectively diagnose and potentially resolve the cruise control issue in your Audi A6.

What are the common problems that could cause the cruise control to stop working in a 1998 Audi A6?

When dealing with cruise control issues in a 1998 Audi A6, it's essential to understand the common problems that may be at play. 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, vacuum leaks can disrupt the system's ability to maintain speed, leading to inconsistent performance. Another potential issue is a defective speed sensor, which can provide inaccurate speed readings and cause the cruise control to malfunction. Problems with the throttle, such as a sticky throttle cable or issues with the throttle position sensor, can also hinder the system's operation. Lastly, electrical problems, including blown fuses or a malfunctioning cruise control module, can result in complete failure of the cruise control system. By systematically checking these components, DIYers can effectively troubleshoot and resolve cruise control problems in their Audi A6.

How urgent is it to repair the non-functioning cruise control in a 1998 Audi A6?

When evaluating the urgency of repairing the non-functioning cruise control in a 1998 Audi A6, it's essential to recognize that while this feature enhances driving comfort, it does not compromise the vehicle's safety or basic functionality. The cruise control system is primarily a convenience tool, particularly beneficial during long highway drives where maintaining a steady speed can reduce fatigue. However, neglecting to address this issue could lead to a more complex problem down the line, especially if the underlying cause is related to electrical or mechanical components that may affect other systems in the vehicle. Therefore, while immediate repair may not be critical, it is advisable to schedule an inspection at your convenience to ensure that your driving experience remains comfortable and to prevent potential complications that could arise from prolonged neglect.

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