Originally Posted by Rolf-Dieter
You might be quite correct. My former Z4 35i had no iDrive nor does my 11M3 that I will trade in tomorrow.
On my o9sDrive Z4 35i I also had a bad monitor they do fail quite often if they are external, I think BMW put them on the inside of the wheel (part of the air valve) on US cars because there are more cars being sold in the US then Canada and they may have had more complains about it (I only assume this not sure about it).
I therefore must assume at this point in time that only if one has the iDrive will one get this notification. I will know more about this once I take delivery tomorrow of my 12M3 and have a chance to review the manuals.
I have a 2011 M3 with i-drive. It has a picture of the car on one of the screens and so far shows all 4 wheels lit up in green. Manual says the car will indicate which one is flat by changing colour. Not hard to do really as they use the ABS sensors to find the flat tire. The effective rolling diameter of a flat tire is much less than an inflated tire. If the steering wheel is straight ahead and one wheel is turning faster than all the others it is likley going flat. ABS sensors are designed to measure differences in the rotational speed at all 4 wheels.