2020 Lexus RX450h Cruise Control Isn't Working

Troubleshooting Common Issues with Cruise Control in Your 2020 Lexus RX450h 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 2020 Lexus RX450h 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 2020 Lexus RX450h 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.

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 are the initial diagnostic steps to troubleshoot the cruise control issue in a 2020 Lexus RX450h?

When troubleshooting cruise control issues in your 2020 Lexus RX450h, it's essential to adopt a systematic diagnostic approach. Begin by checking the cruise control fuse, as a blown fuse can easily disrupt the system's functionality. Next, inspect the cruise control buttons on the steering wheel to ensure they are responsive and not stuck, as this can also lead to malfunctions. Following this, verify the operation of the speed sensor, which is crucial for the cruise control to function correctly; a faulty sensor can prevent the system from engaging. Utilizing a diagnostic scanner to check for error codes can provide insights into any underlying issues that may not be immediately visible. Additionally, ensure that your brake lights are functioning properly, as a malfunctioning brake light switch can inadvertently disable the cruise control. Finally, inspect the vacuum lines for any signs of leaks or damage, as these can significantly impact the system's ability to maintain speed. By following these steps, you can effectively diagnose and address the cruise control issue in your vehicle.

What are the common problems that could cause the cruise control to stop working in a 2020 Lexus RX450h?

When the cruise control in your 2020 Lexus RX450h ceases to function, it can be frustrating, but understanding the common issues can help you troubleshoot effectively. One frequent culprit is a faulty speed sensor, which is essential for the cruise control system to accurately gauge your vehicle's speed. If this sensor malfunctions, the system may fail to engage or maintain the desired speed. Another common issue is related to the brake light switch; if this switch is defective, it can cause the cruise control to disengage unexpectedly whenever the brake pedal is pressed. Additionally, a malfunctioning throttle actuator can disrupt the communication between the cruise control system and the engine, leading to operational failures. It's also worth checking for a blown fuse, as this can render the cruise control system inoperable, requiring a simple fuse replacement to restore functionality. Lastly, a defective cruise control module itself may be the root of the problem, necessitating repair or replacement to get your cruise control back in working order. By identifying these potential issues, you can take the first steps toward diagnosing and fixing your cruise control system.

How urgent is it to address the malfunctioning cruise control in my 2020 Lexus RX450h?

When it comes to your 2020 Lexus RX450h, addressing a malfunctioning cruise control system is not just a matter of convenience; it is a critical safety concern that demands immediate attention. A malfunction can lead to erratic vehicle behavior, such as unexpected acceleration or deceleration, which significantly increases the risk of accidents. Moreover, cruise control issues may signal deeper electronic system or sensor problems that could compromise other essential functions of your vehicle, potentially leading to more severe malfunctions down the line. Ignoring these symptoms can also result in decreased fuel efficiency and performance, ultimately escalating your maintenance costs. By prioritizing the diagnosis and repair of your cruise control system, you not only enhance your driving experience but also safeguard your vehicle's integrity and your own safety on the road. Therefore, it is advisable to consult a qualified mechanic as soon as you notice any irregularities with your cruise control.

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