N490
N491
N563
Igniter for exhaust valve for driver airbag
Igniter for exhaust valve for front passenger airbag
High-voltage battery isolation igniter
T16
16-pin connector, diagnostic connection
Diagnostics CAN
Dash panel insert CAN
Sub-bus system
FlexRay
LIN bus
Convenience CAN 2
Input signal
Output signal
Airbag control unit J234
Crash signal
Airbag control unit J234 registers a collision based on the information supplied by internal and external crash sensors. The air-
bag control unit classifies a collision as “minor” or “severe” depending on the severity of the collision. A minor collision is further
subdivided into multiple crash levels depending on the severity. A severe collision is registered if restraint systems, such as seat
belt tensioners and airbags, are deployed. The airbag control unit sends information on the severity of the collision (including the
crash levels) to the data bus. Other bus nodes receive these crash signals and can then take various types of action, e.g. turn on the
interior lighting.
Airbag control unit J234
684_182
Reaction of high-voltage battery to crash signals
When the airbag control unit detects a collision which meets the relevant criteria, the high-voltage battery is isolated for safety
reasons. In the event of a collision, the airbag control unit sends collision signals to the data bus. The gateway (data bus diagnostic
interface J533) relays the signal to the battery regulation control unit J840.
Minor collision
In the event of a minor collision with a corresponding crash level, battery regulation control unit J840 isolates the high-voltage
battery. If the high-voltage battery has been isolated due to a minor collision, it can be reactivated by resetting terminal 15.
Severe collision
In the event of a severe collision, the signal to isolate the high-voltage battery is transmitted by two different pathways. This helps
ensure signal transmission via a redundant (doubled) design.
›
Pathway 1:
As in the event of a minor collision with a corresponding crash level, battery regulation control unit J840 isolates the high-volt-
age battery.
›
Pathway 2:
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