Lexus GS450h Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your Lexus GS450h 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 Lexus GS450h 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 GS450h 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.

Troubleshooting Cruise Control Issues in a Lexus GS450h

When troubleshooting cruise control issues in your Lexus GS450h, it's essential to adopt a methodical diagnostic approach. Start by checking the simplest components, such as the fuses associated with the cruise control system. A blown fuse can easily disrupt functionality, so replacing it may resolve the issue immediately. Next, inspect the cruise control switch located on the steering wheel; ensure it is operational and free from any obstructions. If these initial checks do not yield results, turn your attention to the brake lights, as a malfunctioning brake light can interfere with the cruise control system's operation. If the brake lights are functioning correctly, consider the throttle position sensor, which may require professional assessment if you suspect it is faulty. By systematically addressing these potential issues, you can effectively diagnose and potentially fix the cruise control problem, ensuring a smoother driving experience in your Lexus GS450h.

What Could Cause the Cruise Control to Malfunction in a Lexus GS450h?

When dealing with cruise control malfunctions in a Lexus GS450h, it's essential to understand the common problems that may arise. A blown fuse or a defective brake pedal switch is often the first culprit to investigate, as these components are critical for the cruise control system's operation. Additionally, issues with the throttle control system can disrupt functionality, making it vital to check for any irregularities. The Anti-lock Braking System (ABS) can also play a role; if there are malfunctions here, they may inadvertently affect cruise control. For older models, inspect the vacuum lines, as a break in these can lead to a complete failure of the cruise control system. Furthermore, the control module and various sensors must be functioning correctly, as any faults can lead to erratic behavior. The condition of the throttle body and the operation of the speed sensor are also crucial, as they directly influence how well the cruise control performs. Lastly, checking for error codes, such as P0A38, can provide valuable insights into specific issues affecting the system. By systematically addressing these potential problems, you can effectively troubleshoot and restore the cruise control functionality in your Lexus GS450h.

Why is it Critical to Fix the Non-Working Cruise Control in a Lexus GS450h?

Fixing the non-working cruise control in a Lexus GS450h is not just a matter of convenience; it is an urgent safety concern that should be addressed promptly. When cruise control fails, drivers may experience erratic speed changes, which can lead to dangerous driving conditions and increase the risk of accidents. Additionally, the absence of this feature can lead to driver fatigue during long trips, as constant manual speed control becomes necessary. This not only detracts from the driving experience but can also result in decreased fuel efficiency, as maintaining a steady speed is often more economical than frequent acceleration and deceleration. Furthermore, a malfunctioning cruise control system can negatively impact the vehicle's resale value, as potential buyers typically seek well-maintained cars with all features operational. Lastly, addressing the cruise control issue may uncover other underlying problems within the vehicle, making it essential to act quickly to avoid further complications. In summary, the urgency of fixing the cruise control in a Lexus GS450h cannot be overstated, as it directly affects safety, comfort, efficiency, and the vehicle's overall value.

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