How does the tire air pressure sensor on the GS (or any other Lexus for that matter) work? Is there an actual sensor within the wheel that detects the pressure, or a sensor on the valve stem perhaps? If there's a physical sensor on the wheel itself, what happens when someone gets new rims?

 

Earlier versions detected a variance in the wheel speed of the low tire.

Newer regulations require a RF sensor that is registered with the tire pressure sensing computer. The sensor is behind the valve stem in each wheel.

 

So if it's part of the stem, then as long as the new rims are fitted with the same stem, it should be good?

 

the sensors are part of the valve stem assembly. Since the sensors have a housing that sits inside the rim, you need to make sure that any new wheel you purchase is TPS compatible. Many of the most popular makes of wheel (volk, work, HRE, etc) are not TPS compatible because they have a reverse lip which doesnt give enough clearance for the TPS sensor.

If you choose a wheel that is not TPS compatible, your options are to either (a) band the sensor to the barrel of the wheel, (b) go without the sensors or (c) fool the sensors by putting them inside some pressurized container (like a wheelbarrow tire, PVC pipe, etc)

Option C doesn't give you use of the sensors, it only eliminates the annoying low pressure indicator on the dash for the newer cars where you can not disable the TPS system.

 

forgot, there is an option D. You can have your wheel shop drill a hole in the new wheel in a location where the TPS sensor will fit. Eternity3GS posted a thread with pics a while back on how to do this.

 

I had my sensors strapped to inside the barrell of my HREs and the TPS Check System light keeps flashing. I've disconnected my battery for 20 minutes and still nothing works. I may just go to the dealer and have them reset the check system.

 

Are you guys even sure this works? About 4 months ago my dad picked me up from a friends house and from our house to my friends he didnt realize he had a flat and when i saw the car i told him and nothing on the dash beeped or alarmed him in anyway... This rendered this feature useless, because i think it only detects SUDDEN drops of PSI and that means a blown tire and if you cant feel the difference between driving on a tire or on a rim then... yeah. Anyone else have the same situation as me? This is in the 05 LS.

kPZ ^_^~

 

it does work. I have mine banded to the inside of my Works and one rainy day, the cold air dropped the tire pressure from 32psi to 29psi. low pressure alarm went off as designed.

 

As a matter of fact, my low pressure sensor went off this afternoon as I was driving. I immediately pulled over to the nearest gas station, checked my air pressure (which I haven't checked in a while), and found that three tires were at 30 psi while one was at 28 psi. Filled them all up to 36 psi and the notification disappeared from the dashboard. The sensors definitely work.

 

Went to the dealer and talked to the service manager whi is supposed to be the guru of Lexus. He says:

1) if I had the sensors strapped to the inside of the rims, to make sure the little hole on the sensor is not cover by the metal strap. If it is, I will continue to get the "check system" light.

2) He could mount all 4 inside the spare tire in the trunk and that would prevent the sensor from activating.

I honestly would rather have my sensors working for me and protect my big HRE investment so I will continue to search for a solution to this ASAP

 

let me know mine just went off on my asantis today

 

If you get a set of iforged wheels they should be OEM tire sensor friendly, no need for extra drilling or a stainless steel strap! All you need to do is purchase a new set of sensors (qty 4) or retrieve and use your sensors from your OEM wheels. If you buy new sensors then the dealer or someone with one of those fancy Lexus handheld computers will need to program your new sensor serial numbers into your "2nd tire" settings.

 

i paid to have sensors transferred to my Work wheels. 2x the sensors went off b/c of low pressure. worked perfectly. that being said, i had to put my stocks back on until my new tires come in. no sensors on the car, and no light has gone off... so, it seems like the sensors generally work, but are not failsafe...

 

how did they mount ur sensors in your works.

my friend who works at the tire place i got them mounted at says the straps isnt the way to go, and im not drilling in my rim fck that

 

Why the tire pressure sensor doesn't report which tire and what the tire pressure for that tire is, is beyond me. Tire pressure goes lower when the weather gets colder and I'm out in bad weather trying to figure which tire is low or if the run flat is truly flat. Cadillac, Jags, Infinity, MB, and Vettes: all show the tire pressure.

Also, while I'm whining, the windows are on retained power, the headlights are on retained power, but the radio goes off the second I turn the car off, what's that?