Lexus LC500 Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your Lexus LC500 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
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25% chance it's the
Throttle
0%
20% chance it's
Something else
The most common reasons a Lexus LC500 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 LC500 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.

Troubleshooting Cruise Control Issues in a Lexus LC500

When troubleshooting cruise control issues in your Lexus LC500, begin with the simplest potential problems. Start by checking the fuse associated with the cruise control system, as a blown fuse can easily disrupt functionality. Next, inspect the brake lights; if they are not functioning correctly, it may indicate a faulty brake switch, which can prevent the cruise control from engaging. If these initial checks do not resolve the issue, look for any warning lights on the dashboard, particularly the check engine light, as engine-related problems can also affect cruise control performance. Additionally, familiarize yourself with the specific features of your LC500, such as the Adaptive Cruise Control system, and ensure you understand how to engage and disengage it properly. This knowledge is crucial, as improper use can lead to confusion about whether the system is functioning correctly. Lastly, be aware of any unique issues reported by other LC500 owners, such as alarm triggers or discrepancies in the satnav, as these can provide insights into potential underlying problems. By following this diagnostic approach, you can effectively identify and resolve cruise control issues in your vehicle.

What Could Cause the Cruise Control to Malfunction in a Lexus LC500?

When diagnosing cruise control malfunctions in a Lexus LC500, it's essential to consider a range of common problems that could be affecting the system. One frequent issue is a failed control module, which can disrupt the communication between various components. Additionally, sensor or switch failures, particularly with the throttle position sensor, can lead to erratic behavior, such as the engine overcompensating with fuel, resulting in black exhaust. Electrical issues, such as blown fuses or defective brake pedal switches, can also prevent the cruise control from engaging. Furthermore, problems within the throttle control system or the engine control unit (ECU) may hinder functionality. It's also worth checking for faulty brake lights or switches, as these can inadvertently signal the system to disengage. By systematically examining these components, DIYers can effectively troubleshoot and potentially resolve cruise control issues in their Lexus LC500.

Why is the Cruise Control Not Working in a Lexus LC500?

When the cruise control in your Lexus LC500 is not functioning, it’s crucial to address the issue promptly, as neglecting it can lead to safety risks and further complications. Common culprits include a failed control module, faulty sensors, or issues with the brake pedal switch, all of which can disrupt the system's operation. A blown fuse can also be a simple yet significant reason for the malfunction, as it completely disables the cruise control. Additionally, problems with the throttle control system or the engine control unit (ECU) can prevent the cruise control from engaging properly. For DIY enthusiasts, it’s advisable to start by checking these components, as timely repairs not only enhance your driving experience but also ensure your safety on the road. Ignoring these symptoms could lead to more severe issues, potentially resulting in costly repairs or dangerous driving situations. Therefore, taking the initiative to troubleshoot and resolve cruise control problems is essential for maintaining the performance and safety of your Lexus LC500.

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