Audi A8 2019 Service Training page 68

Front reversible belt tensioner
If the vehicle is equipped with emergency assist, the driver's
reversible belt tensioner can issue two tactile warnings.
Both tactile warnings serve to bring the driver's attention
back to the traffic situation and to indicate that the driver
should continue steering the vehicle.
› When a tactile warning is issued, the seat belt is ten-
sioned three times in quick succession and then released
again. This produces a "tug" on the seat belt.
› When the other tactile warning is given, the reversible
seat belt tensioner is fully tensioned. This eliminates
belt slack completely, and the seat belt is tensioned.
Rear reversible seat tensioner (optional)
As an option, the 2019 A8 can be equipped with reversible
seat tensioners on the rear outer seats in addition to the
front reversible seat belt tensioners.
Reference
For further information about emergency assist, refer to eSelf-Study Program
Assistance Systems.
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Front reversible belt tensioner
Rear reversible seat tensioner
990393, The 2019 Audi A8 Driver
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