Mazda RX-8 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your Mazda RX-8 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
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25% chance it's the
Control Module
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25% chance it's the
Throttle
0%
20% chance it's
Something else
The most common reasons a Mazda RX-8 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 Mazda RX-8 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.

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.

Troubleshooting Cruise Control Issues in a Mazda RX-8

When troubleshooting cruise control issues in your Mazda RX-8, begin by checking the most accessible components, such as the control module, sensors, and switches. These parts are often the first to fail and can be easily inspected for signs of wear or damage. Next, examine the throttle actuation system, as any problems here can directly affect cruise control functionality. A thorough inspection of the entire cruise control system is crucial; look for any loose connections or faulty wiring that could disrupt operation. If your RX-8 has been retrofitted with cruise control, be aware of potential limitations, such as a maximum speed cap, which may require adjustments. Lastly, if your vehicle is a UK S1 model that had cruise control added post-manufacture, ensure that the firmware is up to date, as outdated software can disable the cruise control feature in the powertrain control module (PCM). By following this diagnostic approach, you can effectively identify and resolve the issues affecting your cruise control system.

Troubleshooting Cruise Control Issues in a Mazda RX-8

When troubleshooting cruise control issues in your Mazda RX-8, it's essential to understand the common problems that may arise. One frequent culprit is a failed control module, sensor, or switch, which can disrupt the system's functionality. Additionally, throttle actuation problems can prevent the cruise control from engaging properly. It's also crucial to check for a blown fuse, a faulty brake light, or a malfunctioning brake switch, as these components are integral to the cruise control operation. If your check engine light is illuminated, it may indicate an underlying engine-related issue that could affect the cruise control system. Interestingly, even seemingly unrelated problems, such as a malfunctioning coolant level sensor, can impact cruise control performance. For a thorough diagnosis, refer to your owner's manual for specific troubleshooting steps, and consider consulting a professional mechanic if the issue persists, ensuring your cruise control system is restored to optimal working condition.

Why is the Cruise Control Not Working in a Mazda RX-8?

When the cruise control in your Mazda RX-8 malfunctions, it’s crucial to act promptly, as neglecting the issue can lead to safety risks and potentially more significant vehicle damage. Common culprits include a failed control module, defective sensors, or issues with the throttle actuation system. A blown fuse or a malfunctioning brake pedal switch can also disrupt the cruise control functionality. If the "check engine" light is illuminated, it may indicate underlying problems that require immediate attention. To effectively troubleshoot, start by checking for blown fuses and assessing the condition of the brake pedal and throttle body. Utilizing a diagnostic scanner can help identify any error codes related to the speed sensor or other critical components. Addressing these issues not only restores your cruise control but also ensures your vehicle operates safely and efficiently on the road.

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Mazda RX-8 Cruise Control Issues & Repairs | RepairPal