2018 Lexus GS350 AC Isn't Working

Common Causes of AC Malfunctions in Your 2018 Lexus GS350 and How to Resolve Them

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
37% chance it's the
Refrigerant Leak
0%
21% chance it's the
Climate Control Electrical Issue
0%
12% chance it's the
AC Compressor
0%
30% chance it's
Something else
The most common reasons a 2018 Lexus GS350 AC isn't working are a refrigerant leak, an electrical climate control issue, or a problem with the air conditioning compressor.
  • Refrigerant Leak: A refrigerant leak can occur due to damaged hoses, seals, or connections, resulting in decreased cooling efficiency in the air conditioning system.
  • Climate Control Electrical Issue: A faulty climate control module or a blown fuse could be causing the electrical issues in the climate control system.
  • AC Compressor: A faulty AC compressor may be due to a lack of lubrication, electrical issues, or internal mechanical failure, resulting in inadequate cooling performance.
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.

What are the steps to diagnose the AC issue in a 2018 Lexus GS350?

To effectively diagnose the AC issue in your 2018 Lexus GS350, start by checking the air filters, as dirty or clogged filters can significantly restrict airflow and diminish AC performance. Next, inspect the refrigerant levels; low levels may indicate a leak, which is crucial to address early on. Following this, examine the compressor for any signs of damage or malfunction, as it plays a vital role in the AC system's operation. Testing the thermostat is also essential, as a faulty thermostat can lead to inconsistent cooling. Additionally, look for any visible leaks in the AC system, as these can directly impact its efficiency. Don’t overlook the electrical components; faulty connections can cause various issues, so a thorough inspection is necessary. If these steps do not resolve the problem, or if you encounter complexities beyond your expertise, consulting a professional mechanic or HVAC technician is advisable to ensure proper diagnosis and repair. By following this structured approach, you can systematically identify and address AC issues in your vehicle.

What are the common problems that could cause the AC system to stop working in a 2018 Lexus GS350?

When the AC system in a 2018 Lexus GS350 ceases to function, several common problems may be at play. One of the primary culprits is low refrigerant levels, which can significantly hinder the system's ability to cool the air effectively. If the refrigerant is low, it may indicate a leak that needs to be addressed. Another frequent issue is a faulty compressor; if the compressor is not operating correctly, it can prevent the system from circulating refrigerant, leading to inadequate cooling. Additionally, electrical issues such as blown fuses, malfunctioning relays, or damaged wiring can disrupt the AC's operation, making it essential to check these components. A clogged or leaking condenser can also impair performance, as it is responsible for dissipating heat from the refrigerant. Lastly, a malfunctioning blower motor can result in poor airflow from the AC vents, further diminishing the system's effectiveness. While some of these issues can be diagnosed and potentially fixed by a DIYer, others may require the expertise of a qualified technician to ensure proper repair and functionality of the AC system.

How urgent is it to address the AC failure in a 2018 Lexus GS350?

Addressing an AC failure in a 2018 Lexus GS350 is crucial for several reasons. First and foremost, a functioning air conditioning system is essential for maintaining a comfortable driving environment, particularly during hot weather or long trips. When the AC is not working, it can lead to discomfort that distracts from the driving experience. Additionally, safety is a significant concern; a malfunctioning AC can create a hazardous situation in extreme heat, as it may impair your focus on the road. Moreover, neglecting AC issues can result in more severe damage to the system, leading to costly repairs down the line. By addressing the problem promptly, you can avoid these complications and expenses. Lastly, keeping your vehicle in good condition, including the AC system, is vital for preserving its resale value. Timely repairs not only enhance your driving experience but also protect your investment in the long run. Therefore, while it may not seem like an immediate emergency, taking swift action on AC failures is advisable for comfort, safety, and financial reasons.

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Troubleshooting 2018 Lexus GS350 AC Issues | RepairPal