My system actually works from what I can tell. Had a low tire, fixed it and the light went off. Still, I want to know more about it and can't seem to find any info. Does anyone know where to buy the sensors? Do you know what frequency they are (315?). I am mounting up a new set of tires and rims and would like to go ahead and put new sensors in if I can get them programmed to work. Any help appreciated.

 

Your TPMS system is a part of the wheel hub assembly, it's not in the valve stem.

The way that it works is when one tire is seen as spinning different than the others, the car just assumes that the tire is lower on air.

 

Well that is very interesting. So it is a part of the ABS system, with the wheel sensor? I have been googling for weeks trying to find info. So no way new ones in the tire can be programmed to the dash? Thanks

 

The TPMS in these cars is controlled via the EBCM (Electronic Brake Control Module, commonly referred to as the ABS module). As Chibi said, it uses the wheel speed sensors, which are build into each wheel hub, performs some fancy math to determine a difference in rotation as a result of loosing tire pressure. I believe GM claims it has to be at least 12lbs low to trip the warning, but I had it happen with 5lbs low. I assume GM claims 12lbs because how "iffy" the reliability is. But many cars used this design, adding you a feature with technology already in your car. Kind of a cool thought. It was later the more reliable method with the valve stems came about (not sure, but it may have been a government ordered safety change).

The system is calibrated simply by driving the car. If you fix a tire pressure issue, then you may need or should reset the monitoring system (which is commonly done via the factory radio).

 

As I suspected, once I knew how it operated. I didn't have to do anything but fix the tire. In fact I just pulled the valve core and filled it with slime...lol. It worked. I am spoiled knowing my tire pressure though, and Amazon has some units that work off of the valve stem cap as cheap as $30. Probably going to grab one, but nice to know mine is working correctly. Snared some nice factory rims and bought some Toyo's off a guy that had literally just driven them two blocks and got T - boned. They are Extensa A/S. Gave him $250. So now I can just go have them mounted and stop worrying about the TPMS. Thanks everyone.

 

Yeah from what I understand only the 2005 SS Supercharged had this system on it. I have one with every option available that year (as far as I know). Love to know how many SC were built in 2005.