2003 Mitsubishi Diamante Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your 2003 Mitsubishi Diamante and How to Fix Them

Find Repair Location
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 2003 Mitsubishi Diamante 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 Mitsubishi Diamante 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 throttle position sensor fails, the engine's computer tends to overcompensate with fuel, leading black exhaust coming from the tailpipe. There is a strong possibility of engine misfires, and the check engine light will come on.

Throttle position sensors can also develop "dead spots," or certain places along the throttle curve where it doesn't get a reading. When this happens, the above symptoms can occur but then stop when you further press or let off the gas pedal.

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.

If the cruise control refuses to turn on at all, the actuator could be at fault. Likewise, if the cruise control stays on but does not maintain a consistent speed, the problem could be a bad actuator. In extreme cases, a malfunctioning actuator could cause the throttle to stick and prevent the vehicle from slowing down. These symptoms may point to a bad actuator. They may also point to other problems with the cruise control and related systems.

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.

What are the steps to diagnose the non-functioning cruise control in a 2003 Mitsubishi Diamante?

When diagnosing the non-functioning cruise control in a 2003 Mitsubishi Diamante, it's crucial to follow a methodical diagnostic approach that prioritizes simpler solutions before tackling more complex issues. Begin by checking the cruise control fuse located in the fuse box, as a blown fuse is a common culprit that can easily be replaced. Next, inspect the cruise control buttons on the steering wheel to ensure they are working properly, since malfunctioning buttons can prevent the system from engaging. After that, verify the functionality of the speed sensor, which is essential for the cruise control to operate correctly. It's also important to examine the vacuum lines for any leaks or blockages, as these can significantly disrupt the system's performance. If these preliminary checks do not resolve the issue, consider testing the cruise control module, which may require specialized diagnostic tools. Additionally, using an OBD-II scanner can help uncover any error codes that might indicate the source of the problem. If you are still unable to identify the issue, seeking assistance from a professional mechanic is recommended, as they have the expertise and equipment necessary to diagnose and repair more intricate problems. By adhering to this structured approach, you can effectively troubleshoot and potentially fix the cruise control malfunction in your Mitsubishi Diamante.

What are the common problems that could cause the cruise control to stop working in a 2003 Mitsubishi Diamante?

When troubleshooting cruise control issues in a 2003 Mitsubishi Diamante, it's essential to understand the common problems that may lead to its failure. One of the primary culprits could be a faulty cruise control switch, which may prevent the system from engaging or disengaging as intended. Additionally, a blown fuse within the cruise control circuit can disrupt its operation entirely, making it crucial to check the fuse box for any issues. Another potential problem is vacuum leaks, which can hinder the system's ability to maintain speed, resulting in erratic performance. Furthermore, a defective speed sensor can impede the cruise control's capacity to accurately gauge the vehicle's speed, leading to malfunction. Lastly, issues with the brake light switch can also pose a problem, as they may prevent the cruise control from disengaging when the brakes are applied. By systematically examining these areas, you can effectively diagnose and potentially resolve the cruise control problems in your vehicle.

How urgent is it to address the non-functioning cruise control in a 2003 Mitsubishi Diamante?

When it comes to the non-functioning cruise control in a 2003 Mitsubishi Diamante, understanding the urgency of the situation is crucial for any DIY enthusiast. While this issue may not pose an immediate threat to the vehicle's drivability, neglecting it can lead to a less enjoyable driving experience, particularly on long journeys where cruise control is most beneficial. The convenience of maintaining a steady speed without constant foot pressure on the accelerator can significantly enhance comfort during highway travel. Moreover, while the malfunctioning cruise control itself may not directly compromise safety, it can contribute to driver frustration and distraction, especially during extended trips. Therefore, addressing this issue promptly not only restores a valuable feature but also ensures that your driving experience remains smooth and enjoyable. Taking the time to troubleshoot and repair the cruise control system can prevent potential complications down the road, making it a worthwhile endeavor for any car owner.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.