4.2.5. Sending the crash message
In the event of a collision involving triggering of the restraint systems, the Crash Safety Module sends a crash message to the users in the bus-system network. Parallel to this, the TCU is informed via a direct single-wire connection to transmit an emergency call.
Then, the respective control units perform the following functions depending on the crash severity:
CONTROL UNIT FUNCTION DESCRIPTION CHART
| Function | Control unit |
|---|---|
| Switch off electric fuel pump | Digital Motor Electronics (DME) Via electronic fuel pump control (EKPS) |
| Switch off the auxiliary heating | Integrated automatic heating and air conditioning (IHKA) (Not for US) |
| Release central locking | Junction box electronics (JBE) |
| Switch on hazard warning flashers | Footwell module (FRM) |
| Switch on interior lights | Footwell module (FRM) |
| Transmit emergency call (only when airbag triggered) | Telematics Control Unit (TCU) |