Hi all -

Sorry to ask what should be a basic question, but I've gotten mixed results. I have a 2009 RX 350 and the {!) indicator showed up on my dashboard randomly yesterday as i took the parking brake off and moved into drive from park. At first i thought perhaps I did something...is this possible?

The tires all seem to be fine as far as air pressure. Ironically enough I just picked up my car from the dealership on Friday (3 days ago) for an oil change and filter replacement. I have NOT checked the spare tire...and read online that many people have had this trigger the TPMS indicator.

1. Can someone help me understand how the spare tire under the floor of my rear cargo could set off a tire pressure monitor?

2. If the spare tire could be the culprit.... could someone else please explain how i check and reset the indicator light?

I'd like to avoid going to the dealership again....just annoying assuming this is a glitch or mistake by the car. If i can fix myself would be awesome.

Thanks in advance, have owned the car since March under the CPO program and slowly figuring out all the little things...good and bad.

Best,
Joe

ps - Does anyone else find it annoying that a 2005 GMC truck will tell you the air pressure in each individual tire yet a 2009 lexus only has a generic {!) symbol telling you to check one of the five tires? (and yes i also have a tape deck too... still amazed that some VP signed off on that in a 2009 model)

 

did you check the air pressure in the tires? Tis the season and the dramatic temp drops of late in the NE is most likely cause aka pV=nRT

Assuming it's just the air pressure, the light is reset (aka turned off) by inflating them to the correct cold PSI rating (listed on plate in driver door jamb).

 

BTW, if the spare is too low, the TPMS reset does not reset. Unfortunately, Lexus does not provide a convenient way to check the spare.

 

Thanks guys. A few more questions please.

1. So cold weather means my tires should have a different pressure and once I adjust to the desired PSI (inside door label said 30) the alert should reset itself?

2. The same TPMS monitors the spare same as the four tires is use???

3. Ad if the spare has a low PSI I need to unlatch it and correct the psi to reset the car alert?

Thanks again,
Joe

 

Joe, I had a TPMS reset button under the steering wheel on my 330. You might want to take a look. Sorry, I'm not familiar with the 350. There is a sequence to resetting in the manual. Takes only a few seconds to do. This is done after bringing the tire pressure to specs. Cold weather will definitely lower the pressure. I recall TPMS goes off around 27.

BTW, I have tire pressure reading inside the cabin of my 450h but it's random. Lexus is getting closer

 

Cold air makes the tires lose pressure by 1-2 pounds per 10 degrees. So when the temperature goes down by 50 degress, you lose 5-10 pounds of pressure. If you refill to about 30-32 psi, including the spare, the light should go out.

 

It is almost always the spare tire causing the light to come on in my RX350.

All you need to do is go to the gas station. Lower the spare. You dont need to take it off the holder. Just drop it till it hits the ground. With the air valve toward the bumper.

Put in the 32 PSI in all the tires. Put the keys in the car and go to ACC. You dont need to start the car. Underneath the steering wheel at the very bottom of the dash closest to the brake pedal. You will see a small eraser size button. Hold it for about 15 seconds.

Start the car and the lights will flash. Then go out.