I would imagine that there is a sensor mounted in each corner of the car, probably located in each fender, that "reads" the tire pressure in that wheel. Then the hard wiring sends the signal back to the appropriate location on the gauge to display the pressure for each tire on the diagram. Just guessing, though.

 

i will put new wheels on as well and my car have tpms. is there a f'k fuse i can just pull to kill the system?

also, how to kill the airbag light, i have aftermarket seats. PIWIS will not work.

 

Reference to tire size was from this post that you made:
https://rennlist.com/forums/996-turbo-forum/232659-new-wheel-setup.html

Did I read somthing wrong?

What car DO you own?

 

Well its a 996/997 Turbo with 18" and 19" wheels, of course. how silly of you MJ not to realize that.

 

MJ Jones- it is a 2006 997 c4 cab- sold the turbo S - anyway i had the sensors mounted by a tire shop yesterday with the straps and it is working fine now...thank god! Let this post be a lesson to everyone with 997 and TPMS (soon to be standard on all cars..) make sure you put sensors back on via air valve or straps, system cannot be shut off!!!

 

you put sensors back on via air valve or straps,
________
can you elaborate?
how do i do this?

 

If you have TPMS in your 997 ( requiured for all 2007 US vehicles) and planning to change wheels you must remove each sensor and reinstall in new wheels. Some wheels do have the ability to attach to air valve stem but many 3 pc forged/reverse lip wheels do not (like mine) and i found out the hard way you must get the straps (usually obtained from wheel manufacturer) and place in side of wheel and under tire and closest to air valve stem. In the 997, you have a generation 2 Beru TPMS and therefore each wheels sensor transmits a frequency to a specific trigger transitter (installed in car not wheel) and then converts the signal to an LIN and signal goes to center control..then the onboard computer reads the signal and "learns" the wheel configuration,air pressure and tire temperature...mine reactivated after 6-8 min. of driving and was back to normal.

 

The TPMS sensors are nopt wheel dependent. Their proximity to each receiver is what determines location. I purchased a set of wheels and winter tires, and four sensors through ebay. Mounted the sensor without worring about which sensor went in which wheel location. It took a couple of hours for TPMS to learn and calibrate after I set it to winter mode and it works perfect. It wasn't even installed by Porsche dealer. It was done at a tire place.

 

I have 19" aftermarket wheels on my car, and the TPC warning light did not even come on when my front tire lost all the air. The strange part is I cannot even locate the TPC function from the onboard computer, am I missing something?

 

Agreed - the sensor antenna is in the wheel well and is read from each wheel. On the Cayenne they rotate the tires and the car re-learns itself - same system is in the 997's...

 

To ensure I understand things correctly, lets say I want to buy an extra set of wheels (frequently on e-bay they have OEM wheels people are selling almost new with tires (lobster forks for example) so that if I want to do some autocross/DE etc, I do not have to use my current set. In order for the TPMS to work with the new wheels, can I just buy extra wheel sensors and then when swapping wheels all should be well? Also, I assume the sensor is inside the tire on the wheel, so that would mean removing each tire, mounting sensor, re-installing tire? Thanks in advanced.

 

You are correct to simply buy the tires and ensure you have a set of transmitters in them to avoid the constant swapping (which requires tire dismounting). In short order the car's system should recognize the 'new' wheels. The only intervention on our part is when the diameter changes. Then you go into it and tell it 18 vice 19.

 

I bought an extra set of wheels and winter tires and purchased the sensors on eBay. All I have to do when swapping wheels is change TPMS from summer to wintwr or viceversa and placing the unit in learning mode. It takes afew miles and you are in business.

 

Thanks guys......and Ben should be proud of me for using the serach function instead of starting a new thread, lol