Wheel Electronics System (Tire Pressure Monitoring System), Siemens

WARNING: This page does not describe the selected car, but rather 23 other vehicles, including the 2017 Audi S5, 2017 Audi A5 Quattro, 2016 Audi S5, 2016 Audi A5 Quattro, and 2015 Audi S5. However, it is still accessible from the selected car via links, so may be relevant.

WARNING:

If tire sealant was used, then the wheel electronics on that particular wheel must be replaced.

The Siemens wheel electronics does not have a microencapsulated screw.
A union nut holds the wheel electronics in place inside the rim
The metal valve body serves as an antenna.
The connection between the metal valve body to the wheel electronics must not get damaged.

WARNING:

Counterhold the metal valve from the back by hand when pressing the wheel electronics into the bed on the rim. The connection between the metal valve to the wheel electronics must not get interrupted or damaged. Damaged wheel electronics must be replaced.

-- Press the wheel electronics into the bed.

-- Tighten the wheel electronics to the metal valve with the union nut