Lexus RC350 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your Lexus RC350 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 Lexus RC350 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 Lexus RC350 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 Lexus RC350

When troubleshooting cruise control issues in your Lexus RC350, it's essential to adopt a systematic diagnostic approach. Begin by checking the fuse associated with the cruise control system, as a blown fuse is a common and easily fixable problem. If the fuse is intact, inspect the brake lights and the brake switch; a malfunctioning brake light or switch can disrupt the cruise control's functionality. Next, consider any engine-related issues that may be indicated by a check engine light, as these can also affect the cruise control system. Finally, conduct a test drive while engaging the cruise control, keeping the brake pedal pressed with your left foot. This simple test can help determine if the brake switch requires adjustment. By following this methodical approach, you can effectively identify and resolve the underlying issues affecting your cruise control system.

What Could Cause the Cruise Control to Malfunction in a Lexus RC350?

When dealing with cruise control malfunctions in a Lexus RC350, it's essential to consider several common problems that could be at play. One of the primary culprits is a failed control module, which can disrupt the entire cruise control system's functionality. Additionally, issues with sensors or switches may prevent the system from engaging or maintaining speed, making it crucial to inspect these components. Throttle actuation problems can also hinder performance, as they directly affect how the vehicle responds to cruise control commands. For older models, damaged mechanical components may be a concern, as wear and tear can lead to malfunctions. Furthermore, electrical issues, such as a blown fuse, can easily disable the cruise control system, so checking the vehicle's electrical system is advisable. Lastly, a faulty brake pedal switch can inadvertently signal that the brakes are engaged, causing the cruise control to disengage. By understanding these potential issues, DIYers can effectively diagnose and address cruise control problems in their Lexus RC350, ensuring a smoother driving experience.

Why is the Cruise Control Not Working in a Lexus RC350?

When the cruise control in your Lexus RC350 is not functioning, it’s crucial to address the issue promptly, as neglecting it could lead to safety risks while driving. Common culprits include a malfunctioning control module, which can disrupt the entire cruise control system, or issues with sensors and switches that may prevent the system from engaging or disengaging properly. Additionally, a failing brake release switch can inadvertently cancel the cruise control, while a blown fuse may cut power to the system altogether. If the engine control unit (ECU) has stored trouble codes, particularly related to emissions, it can also hinder cruise control functionality. Using a diagnostic tool to clear these codes can often resolve the problem. Ignoring these symptoms not only compromises your driving experience but could also lead to more significant repairs down the line, making it essential to troubleshoot these issues as soon as they arise.

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