Audi Q5   Controls   Doors and windows  Central locking system
In the event of a malfunction in the vehicle's electrical system, it may no longer be possible to remove the ignition key.
If you are not able to remove the ignition key because the vehicle battery has discharged (for example), remove the key as follows:
Press the release catch -A- Fig. 1 and pull the emergency key -B- out of the remote control key.
Use the emergency key to lock the vehicle Link.
Have the vehicle's electrical system checked by a qualified workshop.