These instructions apply to the Lexus RX Mk3 (AL10) 2009-2015.
For other models, please choose your vehicle here.
If the tyre-pressure warning has come on in your Lexus RX (2009–2015) — the AL10 — after you’ve adjusted the pressures or changed a wheel, you reset the monitor with the TPMS SET button. The light coming on after you’ve topped up a soft tyre or swapped to winter wheels is completely normal: the system is simply still comparing against the old stored pressures and needs to be told the new values are correct. It is not a sign that anything is broken, and clearing it takes under a minute. Here’s how.
How the RX’s TPMS Works
The AL10 RX uses a direct system: a small sensor inside each wheel measures the actual air pressure and radios it to the car. Because it reads real pressures rather than inferring them from wheel speed, it can flag a genuinely soft tyre accurately — but it also means the stored baseline has to be re-taught with the SET button whenever you deliberately change the pressures. Once you press SET, the car adopts whatever it currently reads as the new “correct” reference.
Before You Start
- Check pressures cold — before driving, or after the car has stood a few hours. Warm tyres read high and will set a false baseline.
- Set all four to the figure on the driver’s door-shut placard (it lists front and rear, and often a loaded figure).
- Park on level ground with the vehicle stationary.
- Have the ignition ready to switch on — you do not need to start the engine or hybrid system.
- Don’t forget to refit and tighten the valve caps.
Resetting the System
- Park level and set all four tyres to the correct cold pressures (placard in the driver’s door shut).
- Turn the ignition on (you don’t need to start the engine/hybrid system).
- Press and hold the TPMS ‘SET’ button (low on the dash near the steering column) until the TPMS warning light blinks, then release.
- The system learns the current pressures as the new baseline; it finishes after a short drive.
If the Warning Stays On
- Recheck every corner — a single tyre a few psi low keeps the warning on and blocks the reset.
- Hold SET until the light blinks — releasing early cancels the learn.
- Drive for a few minutes after pressing SET so each sensor transmits and the system confirms.
- After a wheel swap (summer to winter, or a space-saver), re-store the pressures — the baseline you set earlier no longer matches the wheels fitted.
- Cold snap overnight? Pressure drops roughly 1 psi per 5 °C, so a mild morning can dip a corner below spec — top up and reset.
- A slow puncture will let the warning creep back after a reset — if one tyre keeps needing air, have it inspected.
- Still lit with everything correct? A sensor may have a flat battery (they last several years) — look up any stored code on autodtcs.com.
What to Expect After
Once the baseline is stored and you’ve driven a short distance, the TPMS light goes out and stays off for the rest of the trip and beyond, as long as the pressures hold. If it comes back the next cold morning, that’s usually just temperature, not a fault — recheck and top up. A light that returns within the same drive points to a genuinely soft tyre.
Frequently Asked Questions
How do I reset the tyre pressure light on a Lexus RX (2009–2015)?
Set all four tyres to the placard pressures while cold, switch the ignition on, then press and hold the TPMS SET button near the steering column until the warning light blinks. Release it and drive for a few minutes so the sensors report; the light then goes out and the new pressures are stored as the baseline.
Where is the TPMS SET button on the RX?
It’s low on the dashboard near the steering column, on the RX. It’s a small dedicated button, sometimes tucked below the lower dash trim, and it’s only used for this job. If you can’t locate it, your handbook shows the exact spot for your model year and trim.
Why won’t the warning clear after I set the pressures?
The most common reason is that one tyre is still a little below spec — recheck all four cold. The second is that the SET button wasn’t held long enough for the light to blink, so the learn never started. Give it a few minutes of driving after pressing SET before deciding it hasn’t worked.
Do I need a diagnostic tool?
No — a normal reset after adjusting pressures or rotating tyres needs only the SET button. A tool is only required if a sensor itself is replaced and has to be registered to the car, which is a tyre-shop job rather than something you do at home.
Does the spare wheel have a sensor?
Most RX models carry a temporary spare without its own sensor, so it won’t appear in the monitoring. If you fit it, the system may flag the missing corner or simply monitor the three road wheels — drive gently, get the punctured tyre fixed, and reset once the full set is back on.
The light came back the next morning — is a tyre going flat?
Not necessarily. Cold weather lowers pressure, so a tyre set correctly on a mild day can read low after a frosty night and trip the warning. Check all four cold, top up to the placard figure, and reset. If only one corner keeps dropping, suspect a slow puncture or valve leak and have it checked.
If the warning came on with other lights, decode the code on autodtcs.com.
Independent guide — not affiliated with Lexus. Always follow your official service manual and safety precautions. Read our full disclaimer.