Audi A8 2019 Service Training page 78

Transverse dynamics function
If the vehicle oversteers or understeers, the Electronic
Stability Control (ESC) will try to stabilize the vehicle. If the
vehicle becomes unstable because certain physical limits
have been exceeded, Airbag Control Module J234 initiates
partial tensioning of the electrically reversible seat belt
tensioners. A message indicating that Audi pre sense is
active appears in the instrument cluster. No audible signal
is given.
Process diagram of the Audi pre sense basic transverse dynamics function
Key:
Belt slack reduction
Full tensioning
Closing the panoramic
sunroof
System characteristics of the transverse dynamics function
› If Audi drive select is set to "dynamic", the seat belts are
not partially tensioned.
› If Audi pre sense is deactivated in the MMI, the seat
belts are not partially tensioned either.
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If the vehicle can no longer be stabilized, the following
actions are initiated:
› The electrically reversible seat belt tensioners are fully
tensioned. A message indicating that Audi pre sense is
active appears in the instrument cluster. No audible
signal is given.
› The side bolsters of the seats and backrests are inflated
when the seat belts are fully and partially tensioned.
› The side windows and the panoramic sunroof are closed
when the seat belts are fully and partially tensioned.
Visual advance warning
and/or indication of cor-
rective action
Inflation of the seat side
bolsters
› If the vehicle is unstable, Electronic Stability Control is
set to "sport" or "off" and the driver actively applies the
brakes, the seat belts are fully tensioned. A message
indicating that Audi pre sense is active appears in the
instrument cluster. No audible signal is given. The side
windows and the panoramic sunroof are closed.
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Partial tensioning
Closing of the side
windows