John the tyre sensors come in several forms now.
The older ones which were using pressure sensors as fitted to the early Aeros were all you mention. So many now just dis-connected.
The newer ones seem to use the ABS sensors (like every seems to these days) and use the rotation speed to establish the pressure. Amazing that they can deduce it to that accuracy through this. On my Audi before and now on the ML it shows the pressures based on this. It has been very accurate and unlike the older ones no hassle.
I always say that if you need a manual you have not designed the product correctly. Now it seems that the manual is mostly there to carry the warnings and legal dispensation stuff. As Paul comments the access to the on-line manual is also annoying. No doubt it will also become a paid for subscription shortly. Access and updates in line with the software updates the car gets will become chargeable!
I have also often wondered if they employee a specific style of deviant to write these things so that they can be translated to multiple languages with least trouble but then become ineffective in all languages?
