Audi A8 2019 Service Training page 59

Key to figure on page 54:
J104 ABS/ESC Control Module
J187 Differential Lock Control Module
J217 Transmission Control Module
J234 Airbag Control Module
J428 Control Module for Adaptive Cruise Control
J500 Power Steering Control Module
J527 Steering Column Electronics Control Module
J623 Engine Control Module
J706 Passenger Occupant Detection System Control Module
J769 Lane Change Assistance Control Module
J770 Lane Change Assistance Control Module 2
Sensors
The driving dynamics control sensors are integrated in the
airbag control module. They measure acceleration in the X
and Y directions as well as the yaw rate about the Z axis.
The driving dynamics control sensors work in a lower accel-
eration and deceleration range than the crash sensors. The
acceleration and deceleration levels which can occur during
a collision are different to those which can occur when a
vehicle loses grip (for example, oversteer, understeer).
Center Crash Sensor for X/Y Axis G858
G858 is an acceleration sensor. It is a combination sensor
which measures both vehicle acceleration and deceleration
in the X and Y directions. It is used to validate the plausibil-
ity of defined accident events in the longitudinal (X) and
transverse directions (Y).
Crash signal
The Airbag Control Module J234 registers vehicle collisions
based on the information supplied by internal and external
crash sensors. Depending on the severity of the accident
event, the collisions are classified as "minor" or "severe".
An accident event classified as minor is again subdivided
into several different accident severities.
J775 Drivetrain Control Module
J792 Active Steering Control Module
J854 Left Front Seat Belt Tensioner Control Module
J855 Right Front Seat Belt Tensioner Control Module
J1019 Rear Axle Steering Control Module
J1088 Control Module for Left Front Object Detection Radar
Sensor
J1089 Control Module for Right Front Object Detection Radar
Sensor
J1097 Left Rear Seat Belt Tensioner Control Module
J1098 Right Rear Seat Belt Tensioner Control Module
J1122 Laser Distance Regulation Control Module
If the vehicle is equipped with dynamic all-wheel-drive
steering or quattro with sport differential, the driving
dynamics control sensors are duplicated in the airbag
control module. The duplication of the sensors provides
sensor signal redundancy (multiple signals).
Installation location
A severe accident event exists if restraint systems, such as
safety belt tensioners and airbags, are deployed. The
airbag control module indicates the accident severity and
collision levels to the data bus. Other bus users receive this
crash signal and can then take the appropriate action, for
example, shutting off the fuel supply.
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