Instructions: In vehicles with Teiematik, the emergency battery must be replaced every 4 years.
Used Teiematik is located in the intermediate bottom on the front passenger side. Remove the lower pillar trim and floor covering. Unscrew both "arrow" screws on the bottom of the Teiematik control unit and remove the cover.
Disconnect connector "1" and remove emergency battery "2".
Installation is carried out in reverse order. Before disconnecting the battery terminals, activate the service mode of the Teiematik control unit.
Instructions. Before disconnecting the battery terminals, request the security code of the radio/navigation system. When connecting the battery terminals, activate the equipment (radio/navigation system, clock, electric windows, engine) according to the operating instructions and deactivate the service mode of the Teiematik control unit.
[The text is based on materials from the website: AudiManual.ru]