tire pressure
 

how will my car know what the tire pressure is when i put on my aftermarket rims?
anyone know?

Your car will know the pressure becuase it is smart. The only thing you have to do is make sure you can fit the TPMS is your new wheels. Alot of wheels wont work with the TPMS sensors. :thumbdn:

I run about 40-42psi on my 19's

what is TPMS??

tire pressure monitoring system

basically the aftermarket wheel cannot have a valve stem that is perpendicular to the rim of the wheel if you want to use TPMS

i think these rims i am getting racing hart rs-721 wont be compatible.
so will the car throw a code?
what will i have to do?

thx

some people buy a wheelbarrow wheel from home depot pump it to whatever PSI, throw the 4 sensors in to fool the system

someone on the GS forum went as far to drill new holes in the wheel in a location which would make the TPMS compatible, so you have two valve stems, pretty hidden tho

so does that first method actually work?
i was hoping to get some black steelies to put some winter tires on except lexus says the tpm wont fit on them
they also said its possible to just put them all in the spare tire space..or something along those lines

question still stands does it throw a code of sorts?
anyone??

The "tire pressure monitoring system" will trigger an error lamp on the instrument cluster, if it detects low pressure or a missing sensor..

Your tire pressure is indicated on a label attached to the inside drivers door jam. This is the pressure for any wheel.

The wheelbarrow trick should work better with a tubeless tire and wheel. Install the four sensors inside the small tire and pump it to the recommended pressure. This should satisfy the pressure sensors and reset to lamp off. The tire is placed in the trunk, within radio range of it's ECM controller.

thank you, where do i buy it and what is the exact item name.
someone said home depot.. how small is this tire?

The Lexus system may be different, but I thought that the TPMS's measure tire pressures by monitoring the rotational speed of each wheel, comparing it to a known "good" value. If the tire looses air, the rotational speed increases (smaller circumference), and triggers the warning light. Again, the Lexus system could very well be different.

really doubt it that type of measuring system has too many uncontrollable variables to throw off measurements, what if you dont use OEM tires, whats the temperature, etc

Also people ahve done the wheelbarrow thing and it works so its measuring straight pressure

If you reuse the sensors that came with the car and put them in a pressurized wheel, the car will not throw a code (but you do not have the function either).

If you buy new sensors, make sure you write the serial numbers down prior to sticking them in any wheels. Then you have to go to the dealer to have them initiated to the car.

what ive been wondering is how are these transmitters powered, do they have batteries that need replacing

Must be watch or hearing aid type battery. Replaceable when required.