2018 Lexus RC300 Tire Pressure Warning Light Stays On

Resolve Tire Pressure Warning Light in 2018 Lexus RC300: Causes and Solutions

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
40% chance it's the
Tire Leaking Air
0%
30% chance it's the
Wheel Leaking Air
0%
15% chance it's the
Tire Pressure Monitoring System
0%
15% chance it's
Something else
The most common reasons a 2018 Lexus RC300 tire pressure warning light stays on are a leaking tire, a wheel that no longer holds air, or a faulty tire pressure monitoring system.
  • Tire Leaking Air: A puncture, valve stem issue, or rim damage can cause a tire to leak air, leading to loss of pressure.
  • Wheel Leaking Air: A puncture or damage to the tire or rim can cause air to leak, resulting in a loss of tire pressure.
  • Tire Pressure Monitoring System: A malfunctioning tire pressure monitoring system can be caused by faulty sensors or a dead battery in the sensor units.
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 2018 Lexus RC300 tire pressure warning light stays on?

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 a tire pressure monitoring sensor fails, the tire pressure monitoring system control module will recognize a loss in communication and turn on the warning lamp which indicates the failure. This is most often the case. However, the tire pressure monitoring sensor may also fail by reporting incorrect tire pressures. This could cause a flat tire to go unrecognized, or a properly inflated tire to signal a low or high tire pressure warning.

When a relearn is needed, for any reason, the TPMS warning light will illuminate, and many vehicles will display a message relating to the TPMS system being inoperative or loosing communication. It is important to keep a watchful eye on tire pressures when this system is having issues because there is no warning available for underinflation or overinflation of the tires.

Wheels offer very few symptoms, but these symptoms should never be ignored. Visible cracks on the wheels may appear, especially after hitting a large bump, Most often, this will also be accompanied by loss of air from the tire on that wheel. Also, vibration in the steering wheel is very common when the tire is out of balance, and improper wheel nuts or bolts can cause creaking and popping noises to develop. Again, there are very few symptoms, but they should not be ignored.

The only symptoms requiring diagnosis for the tire pressure monitoring system warning lamp is if the warning lamp has illuminated while the tires have correct air pressure, or if the air pressure for the tires is out of specification and the warning lamp is off. This is because the overwhelming majority of cases where the TPMS lamp illuminates is due to the change in ambient temperature.

What steps should I take to diagnose the tire pressure warning light issue in my 2018 Lexus RC300?

To effectively diagnose the tire pressure warning light issue in your 2018 Lexus RC300, begin with a straightforward approach that prioritizes simpler solutions before delving into more complex diagnostics. Start by checking the tire pressure in all four tires using a reliable tire pressure gauge, ensuring they are inflated to the levels recommended in your vehicle's manual. This initial step can often resolve the warning light if the pressure is simply low. Next, inspect the tires for any visible damage, such as punctures or bulges, which could be causing the alert. If the tires appear to be in good condition, proceed to reset the tire pressure monitoring system, as this can sometimes clear false warnings. Additionally, examine the valve stems for any signs of leaks or damage that might trigger the warning light. If, after these checks, the warning light remains illuminated, it may be time to consult a mechanic or dealership for a more comprehensive diagnosis. By following this methodical approach, you can efficiently identify and address the issue, ensuring your vehicle's safety and performance.

What could be causing the tire pressure warning light to stay on in a 2018 Lexus RC300?

When the tire pressure warning light remains illuminated in a 2018 Lexus RC300, it can be frustrating for DIY car owners. One of the most frequent culprits is low tire pressure, which can easily be checked using a tire pressure gauge. Ensuring that all tires are inflated to the manufacturer's recommended levels is crucial for both safety and performance. If the pressure is adequate, the issue may lie with the tire pressure sensors themselves. These sensors can fail or require battery replacements over time, leading to inaccurate readings. Additionally, a malfunctioning sensor may need to be replaced entirely. Another potential problem is the need for system recalibration; sometimes, the tire pressure monitoring system can lose its accuracy and require a reset to function correctly. If these troubleshooting steps do not resolve the issue, it may be wise to consult a professional mechanic for a comprehensive diagnosis, as persistent warning lights can indicate more complex underlying problems.

How urgent is it to address the tire pressure warning light that stays on in a 2018 Lexus RC300?

Addressing the tire pressure warning light in your 2018 Lexus RC300 is not just a matter of convenience; it is a critical safety concern that requires immediate attention. When this warning light remains illuminated, it signals that one or more tires may be underinflated, which can severely compromise your vehicle's handling, braking, and overall stability. Low tire pressure not only increases the risk of a flat tire or blowout—especially dangerous at high speeds—but it can also lead to uneven tire wear and decreased fuel efficiency, ultimately shortening the lifespan of your tires. Ignoring this warning can result in costly repairs and unsafe driving conditions. Therefore, it is essential to check the tire pressure of all tires, including the spare, and inflate them to the manufacturer's recommended levels as soon as possible. Taking these proactive steps ensures your safety on the road and helps maintain the integrity of your vehicle.

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