Audi A8 2019 Service Training page 81

Audi pre sense display
If the vehicle continues to approach and the danger of a
rear-end collision increases, the reversible seat belt ten-
sioners are partially or fully tensioned depending on how
fast your own vehicle is traveling. The reversible seat belt
tensioners are partially tensioned if your vehicle is traveling
at a higher speed and fully tensioned if the vehicle is travel-
ing at a lower speed. If your own vehicle exceeds a preset
speed, reversible seat belt tensioners are not tensioned.
The four reversible seat belt tensioners are connected to
the Airbag Control Module J234 by a sub-bus system.
The reversible seat belt tensioners are:
› Left Front Seat Belt Tensioner Control Module J854.
› Right Front Seat Belt Tensioner Control Module J855.
› Left Rear Seat Belt Tensioner Control Module J1097.
› Right Rear Seat Belt Tensioner Control Module J1098.
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