So looking in the DIY section on www.audidiy.com/a3.html there is a good post on adding TPMS to the A3. In it there is no mention of a TPMS module, only the ABS module, and the control module. The system uses the rotational speed of the wheels to select the pressure drop.

BUT the most recent posts speak about TPMS sensors needing to be installed in the tires plus they mention the TPMS module.

So my question is, did they change the system and if so when? I have a 2008 sline and want to add the TPMS if all i need to do is get the switch, run the wires and make the vag-com changes. But if a new module is required because the system has changed this mod may not be possible any more.

Anybody have any experience or knowledge?

thanks

 

There are two types of tire pressure monitoring systems, passive and direct. The passive system uses the ABS sensors to measure differences in tire rotational speed which changes if a tire starts to deflate and the rolling diameter changes. This sytem is prevalent in Europe.

The USA uses the direct system which measures the pressure directly inside the tire via a mounted sensor. This system is way more accurate with some higher end vehicles actually displaying the pressure for each tire (including the spare).

All cars (not trucks) sold since 2007 in the US are required to have TPMS. Your 2008 (if it is a US or Canadian model) will have the direct system which have the pressure sensors in the tires. You shouldn't have to do a thing.

 

When i bought the car it did not have TPMS, no switch and no system, thus my interest in adding it. But if the car is designed for the direct system the mod outlined under DIY is not possible. So, were the late 2007, early 2008 cars which did not have TPMS installed intended for passive or direct system?

clearly I may need to either go to the cealer and ask or take the dash apart and see if I can figure it out.