Audi A8 2019 Service Training page 88

Assistive brake intervention phase
When the driver applies the brakes, a target braking maneu-
ver can be performed in all of the phases described above
(prefilling of the brake system, reconfiguration of hydraulic
brake assist, prewarning, acute warning, automatic braking).
During the target braking maneuver the Audi pre sense front
system calculates whether the driver has applied sufficient
braking to be able to prevent a collision. If this is not the
case, the required amount of braking is increased (up to
maximum level depending on the situation). Depending on
the situation, ABS/ESC Control Module J104 can instruct the
hazard warning flashers to be activated.
Depending on the situation, the following additional
actions may be initiated:
› The electrical head restraints move into an elevated
position.
› Inflation of the side bolsters in the seats and backrests.
› Closing the panoramic sunroof.
Process diagram showing how Audi Pre sense front responds to vehicles
Key:
Visual advance warning
and/or indication of cor-
rective action
Reconfiguration of
hydraulic brake assist
Closing of the side
windows apart from a
residual gap
Full tensioning
Movement of the electri-
cal head restraints into
the upright position
84
› Closing of the side windows apart from a residual gap.
› Partial tensioning of the electrically reversible seat belt
tensioners
› Full tensioning of the electrically reversible seat belt
tensioners.
› Display of corrective action by Audi pre sense in the
instrument cluster
If the vehicle brakes itself to a standstill without driver
intervention, a driver take-over prompt appears in the
instrument cluster and further audible signals sound.
These signals will alert the driver to the fact that he must
actively take control of the vehicle (for example, by apply-
ing braking). If the driver fails to take control of the vehicle,
the system will release the brake and the vehicle will start
to move.
Audible warning beep
Acute warning by braking
impulse
Closing the panoramic
sunroof
Inflation of the seat side
bolsters
Driver take-over prompt
Prefilling of the brake
system
Target braking
Partial tensioning
Movement of the upper
backrests into the upright
position
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