Test prerequisites:
The battery voltage should be >12V.
Ignition on, engine off.
No stored fault codes.
Procedure:
Choose the function: Key programming.
Observe the "Fasten seat belt"-lamp.
Press periodically (1 sec) the lock-button on the key-remote until the "Fasten seat belt"-lamp flashes one time. More than 8 presses on the lock-button can be needed.
If multiple keys should be programmed:
Remove the key from the ignition lock.
Insert the next key in the ignition lock.
Turn the key to position On.
Repeat steps 3 and 4.
Exit the function by "Exit key programming".