arU4ic

Ok, so, I've set my tmps twice since I got my S3, and it did indeed report a tire that was indeed lower in pressure than the other 4.

HOWEVER, on Fri my TMPS let me drive all the way home from work (18 miles) on an almost flat tire. Arg.

Is the TMPS on the A3/S3 the type that doesn't actually report pressure, but reports wheel speed differences (or however that works)?

uberwgn

Pressure is not reported with these newer sensor-less systems.


I find the response to be kinda slow compared to the original design.

dlmmail18

Should I be worried about tire pressure so early? Typically I set it and forget until I am back in for service day or notice something funky.

How did your tire get to almost flat on a set of new rubber in just a month or two?

arU4ic

Turns out I had a nail in the tire… not sure why the TMPS didn't go off.

Gonna vag for errors this weekend.

Fixeroh

Besides my wife's 2013 Subaru Tribeca, my S3 is only other vehicle I've owned with TPMS. Prior to purchasing my 18 in winter wheel/tire package, I talked to my Audi service department. He explained the sensors for the TPMS are in the hub. I wasn't sure how this worked exactly and found the following information below. I don't remember where I found it however and cannot give credit to the original poster. Hope it helps.

"The newer Audis don't have pressure sensors in the tires; instead, they use the ABS sensors and analyze the waveform to determine if a tire is low. Thus, the car has no tire pressure information at all.

In order for TPMS to work with this system, you need to set the pressures at the correct value and then reset the TPMS learning/calibration in the MMI. Once you do this, the system will learn the waveform/signature for the particular tires and particular pressures. After about 20 minutes of driving at various speeds, the system finishes 'learning'.

In theory, the system will warn you if a tire is 20% low, and can figure out both single-tire and multiple-tire scenarios. I have not actually tried it to make sure it works.

Hope this helps. While there are no absolute readings, this approach allows for using rims without the TPMS sensors, avoids the replacement of sensors due to breakage when changing tires/batteries dying, etc. and in general makes for a more reliable, easier to maintain TPMS system that still provides useful information about dangerously low pressures. But you can no longer check your tires without using a gauge and getting some of that Audi brake dust soot on your fingers."

drober30

So it is just a generic light that informs you that "a tire" is low when in fact it could be more than one?

DennisMitchell

That is correct. I will tell you that my 2014 Q5 will tell which tire is low.

arU4ic

The S3 does indeed tell me which tire is low, just not what the actual pressure is.

EGainer

My bmw didn't tell the pressures either. It used the rolling circumference to tell if a tire was low instead of the pressure. I would set my tires at 38 and wouldn't get notified until one was 31-32psi. I prefer pressure system, but the other doesn't require pieces to be replaced in the valvestem when you replace the tires.