2019 Lexus RC300 Cruise Control Isn't Working

Troubleshooting Common Issues with Cruise Control in Your 2019 Lexus RC300 and How to Fix Them

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Reviewed by
Andrew Hajjar
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 2019 Lexus RC300 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 2019 Lexus RC300 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.

What steps should I take to diagnose the cruise control issue in my 2019 Lexus RC300?

To effectively diagnose the cruise control issue in your 2019 Lexus RC300, begin with a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Start by examining the cruise control fuse, as a blown fuse can easily disrupt functionality. Next, inspect the cruise control buttons on the steering wheel to ensure they are operational, since faulty buttons can lead to malfunctions. Utilizing an OBD-II scanner is a crucial step; it allows you to identify any error codes that may indicate specific problems within the cruise control system. Following this, check the speed sensors, as they are integral to the system's performance. Additionally, inspect the wiring and connections for any signs of damage or corrosion, which can impede the system's operation. If these steps do not resolve the issue, it may be time to consult a professional mechanic or visit a dealership for a comprehensive diagnosis. By following this structured approach, you can efficiently identify and address the cruise control problem in your vehicle.

What are the common problems that could cause the cruise control to stop working in a 2019 Lexus RC300?

When dealing with cruise control issues in a 2019 Lexus RC300, it's essential to understand the common problems that may be at play. One frequent culprit is a faulty speed sensor, which can hinder the system's ability to detect the vehicle's speed accurately, preventing it from engaging or maintaining speed. Additionally, the brake light switch can cause disruptions; if this switch malfunctions, the cruise control may disengage unexpectedly when the brake pedal is pressed. Another area to check is the fuse associated with the cruise control system; a blown fuse can lead to complete failure of the system, and replacing it is often a straightforward fix. Furthermore, issues with the throttle control, such as a malfunctioning throttle position sensor, can impede the cruise control's performance. Lastly, electrical problems, including loose connections or wiring faults, can also contribute to cruise control malfunctions. By systematically addressing these potential issues, DIYers can effectively diagnose and resolve the cruise control problems in their Lexus RC300.

How urgent is it to address the malfunctioning cruise control in my 2019 Lexus RC300?

When it comes to your 2019 Lexus RC300, the urgency of addressing a malfunctioning cruise control system cannot be overstated. A faulty cruise control can lead to unpredictable vehicle behavior, such as sudden acceleration or deceleration, which poses a significant safety risk not only to you but also to other road users. Moreover, neglecting this issue can adversely affect your vehicle's fuel efficiency, making long drives less economical and enjoyable. Over time, continued use of a malfunctioning system may cause additional wear on critical components, potentially leading to more severe and costly repairs down the line. By addressing the cruise control issue promptly, you not only enhance your driving experience but also help maintain the reliability and resale value of your Lexus RC300. Therefore, it is crucial to take action as soon as you notice any irregularities in the cruise control functionality.

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