So Philly1

The other day my low tire light came on on my dash. Its done this before but i dont remember what i did to get it to go away. One of my tires really was low but i filled all four up when the light first came on. One day in an unrelated visit a mechanic at the dealer told me he had the same problem on an LS and it was the sensor on the spare tire. I even put air in this one!!!! And the light is still on!!! W-T-F!!!! This is really pissin me off.

BTW the thin tire on the 22's isn't the problem, I checked. Anyyyyyybodyyyyy got any thing??

Dave Mac

I don't know what model you have but even if you just refilled all your tires and your spare you may need to reset the TPMS. You will have to check your owner's manual as to how to do this. If that fails you may have to see your dealer re. a damaged sensor.

Dave Mac

airtime

Depending on what year, most do not have any sensors in the wheels. Just reset it yourself. There is a button under the dash to do so. There is a method to the madness to reset it and I don't remember on the top of my head what it is.

I believe this was discussed in detail in another thread. The car calculated that all the wheels should spin the same amount, but as one tire is deflated, it will signal the car's computer that all the wheels are not spinning the same and thus gives the error. Not a very accurate system and not the speediest as you could be losing air for many miles before it notifies you. No need to be pissed off about it, its just the way it is with the LS

So Philly1

Doin a search now. I've got an '04 and i swear til this day i still cant tell which model it is. All i know is its not a UL.





Unfotunately

ayonnebay

It is actually not a "Reset" though - It is an "Initialize".

It's in the Owners Manual (2004LS, Pg 98):

"After replacing tires or wheels, adjust all 4 tires to specified pressure and initialize the tire pressure warning system. To initialize the system, turn the ignition switch to "ON" and push the tire pressure warning system reset switch for longer than 3 seconds with the vehicle stopped. The following message appears

" ! Pressure Initial "

Don't just do a quick press of the button to get rid of the warning, in other words. The system must be initialized.

CarguyinGa

If it has an initialization process, it's a wheel speed sensor based TPM. It uses the wheel speed sensors to monitor the correlation from wheel to wheel. Tires will change the rolling circumference with air pressure changes, lower pressure = smaller diameter, that will make it turn slightly faster than the learned factor. The process is to set all the tires to correct pressure and then initialize it, during straight line driving it will learn the rates of rotation comparing all 4 wheels, if it deviates by a predetermined amount, you'll get a low tire warning. The oddity of this is that changing one tire to a new one(larger circumference) or adding air to one will allow it to think the other 3 may be low and it will alert. Just remember to set all before the initializing

KILLERGS4

when i had this problem i had a nail... small leak was causing the tire warning.. so check again for nails if you alreay tired everything else.

SH212

might be a censor... if all else fails check that

So Philly1

Thanks for the help guys. I initialized it and sure enough it disappeared!!

My deepest thanks!!!!

rhevans

Have a 05 LS, just two weeks old.

Had the same problem 3 times Sat. I checked the tire pressure each time and it was okay. Took it to the dealer. Seems there is a service bulletin out about it. Something to do with the ABS system.

Will be fixed this week.

GRAND_LS 4

iTrader: (2)

The system uses the ABS to calculate the rotation of your tires, and if one is slower, this usually indicates low pressure triggering the light.

On the newer systems (LS460) they started using actual sensors in every tire.

TO reset, hold the reset button above the drivers right knee until the light goes off. I would reset the system when you replace your tires.

ayonnebay

Actually ... until the "initialize" message appears.

Wezee

This switch was the hardest thing to find on my 05. For those who can't find it, try looking way inside where the accelerator is, should be somewhere above the accelerator.. Yes, that's how deep inside it is. Hope that helped.

Weez

Jabberwock

The reset switch is described as being by your right knee. In actuality is more like being by your right ankle - absolutely silly spot to put it. Just keep looking lower and lower and you will eventually spot it. When you are contorted bent over backwards and the pain is really getting bad the reset switch will appear : )

btw - no LS430 of any model year has inboard wheel/tire based pressure sensors. The LS 430 was designed with a very primitive ABS based tire pressure system. On an LS430 the spare tire could be totally flat, or missing entirely, and the ABS system would have no idea. The only thing that can be measured in an ABS based system is the relative rotation of the 4 mounted tires. On an LS430 if you don't move the car, all the tires could be under-inflated and there would be no warning possible for the system to detect until you started driving it down the road. An ABS based system has no way to measure tire pressure. The only thing an ABS based system can measure is the SIZE of the tire, and it can only do that when the car is moving. This also means that when you replace your tires even if they are inflated to the exact same pressure as old tires you just took off you will likely get a TPS warning light simply because the new tires are a slightly different diameter going from worn tread to brand new tread.

warminwisc

Thanks Jabberwock, off I go. The manual is a bit vague on where it is. When it hurts I know I am in the right spot, thanks very helpful buddy!