2019 Lexus RX450h Tire Pressure Warning Light Stays On

Resolve Tire Pressure Warning Light in 2019 Lexus RX450h: Causes and Solutions

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Reviewed by
Bo Fader
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 2019 Lexus RX450h 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 2019 Lexus RX450h 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 are the initial steps to diagnose a persistent tire pressure warning light on a 2019 Lexus RX450h?

To effectively diagnose a persistent tire pressure warning light on your 2019 Lexus RX450h, start by checking the tire pressure in all four tires, ensuring they are inflated to the manufacturer's recommended levels, as low pressure is a frequent culprit for such warnings. Next, inspect each tire for visible damage, including punctures, cuts, or bulges, which could lead to air loss. Don’t overlook the valve stems; examine them for any signs of leaks or damage that might be affecting tire pressure. Utilizing a reliable tire pressure gauge can help confirm the accuracy of your tire pressure readings. If everything appears normal, consider resetting the tire pressure monitoring system, as this can sometimes clear false warnings. Always refer to your vehicle's manual for specific instructions on how to perform a reset. By following these steps, you can systematically troubleshoot the issue and potentially resolve the warning light without needing to visit a mechanic.

What could cause the tire pressure warning light to remain on in a 2019 Lexus RX450h?

When the tire pressure warning light remains on in a 2019 Lexus RX450h, it can indicate several common issues that are manageable for DIY enthusiasts. The first step is to check the tire pressure in all four tires, as low pressure is the most frequent cause of the warning light. If the pressure is within the recommended range, the next consideration should be the tire pressure sensors themselves; a malfunctioning sensor may need to be replaced. Additionally, if the vehicle has undergone recent tire changes or rotations, recalibrating the sensors can help ensure they are accurately reading the tire pressure. It's also important to inspect the tire pressure monitoring system for any electrical faults, which may require a diagnostic tool for proper identification. Lastly, ensure that the sensors are clean and free from any debris or obstructions, as these can interfere with their functionality. By methodically addressing these potential issues, you can troubleshoot and resolve the persistent tire pressure warning light effectively.

What immediate steps should be taken if the tire pressure warning light remains on in a 2019 Lexus RX450h?

When the tire pressure warning light remains illuminated in your 2019 Lexus RX450h, it is crucial to act promptly to avoid potential safety hazards and costly repairs. Ignoring this warning can lead to decreased vehicle performance, increased tire wear, and even tire blowouts, which pose serious risks on the road. Start by checking the tire pressure in all four tires with a reliable gauge, ensuring they meet the manufacturer's specifications. If you find any tires underinflated, use a quality air compressor to inflate them to the correct levels. Additionally, visually inspect each tire for any signs of damage, such as punctures or bulges, as these issues can exacerbate the problem. Once you have addressed any pressure discrepancies or damage, reset the tire pressure monitoring system according to your owner's manual. If the warning light persists despite these efforts, it is essential to seek professional assistance to diagnose and resolve any underlying issues. Taking these immediate steps not only enhances your vehicle's safety but also prolongs the life of your tires, making it a vital part of responsible vehicle maintenance.

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