Audi A8 2019 Service Training page 62

3. A vehicle has been involved in four severe accidents. Each
of these accidents has been recorded in a block. Now
another severe accident occurs. The airbag control
module must be replaced after this accident because a
further block has been used and, as a result, only one
block is left. The control module therefore no longer
meets the condition that at least two of the six blocks
still have to be usable.
Airbag control module faulty
In short, this means that an airbag control module must be
replaced after the 5th accident in which pyrotechnics
deploy. In this case, the airbag control module would
register the event "fault".
Data recording
As mentioned previously, various units of vehicle data are
recorded. Personal data is not recorded. Generally, data is
recorded up to five seconds before an accident and 300
milliseconds after an accident.
This data includes:
› Vehicle speed.
› Engine speed.
› Steering angle.
› Seat belt status (fastened/not fastened).
Diagnostics and read-out tool
The EDR cannot be switched off or deactivated. The data
can be accessed with a CDR tool (Crash Data Retrieval).
Usually only Crash investigators, insurance inspectors, and
or like job roles would have access to the CDR tool. This is
not a tool the typical Audi repair shop has available to use.
Note
Pyrotechnic charges are also ignited in the event of a rollover. For this reason, a rollover also counts as a severe accident.
In this generation of control module, four severe accidents can occur on one side of the vehicle, for example, four head-on
collisions, without the control module having to be replaced.
58
S1
S2
S3
S4
Free
block
Free
block
Key:
L Minor accident or near-accident event
Severe accident
S
No accident event
Free block
Data is still recorded after the accident.
This data includes:
› Type of accident, for example, head-on collision/rear-end
collision/rollover.
› Number of accidents recorded.
› Whether the accident event recording is complete.
The data can be used to analyze accident situations and
obtain insights.
S1
S2
S3
S4
S5
Free
block
Airbag Control Module
J234 faulty
662_023