4.1. Functions of the crash safety module

The main function of the Crash Safety Module is to constantly evaluate all sensor signals in order to detect a crash situation. As a result of the sensor signals and their evaluation, the crash safety module identifies the direction of the crash and the severity of the impact.

Also included is information on seat occupancy and whether or not the driver and/or front passenger have their seat belts fastened. From this information, measures are taken to selectively trigger the necessary restraint systems.

The crash safety module monitors the system itself and indicates that the system is ready for operation when the airbag indicator light goes out.

In the event of a fault during operation, this is stored in a fault memory, which can be read out for diagnostic purposes.

If a crash situation is detected, this is communicated to the other users in the bus-system network by a crash message. The relevant control units respond to this signal by executing their own functions according to the severity of the crash.

These functions include:

• Opening the central-locking system
• Activating the hazard warning flashers
• Switching on the interior light
• Deactivating the electric fuel pump
• Switching off the auxiliary heating
• Automatic emergency call.

Another function of the Crash Safety Module is the acoustic seat belt warning, which uses visual and audible signals to remind the driver and front passenger to fasten their seat belts.

The functions of the Crash Safety Module are divided into the following areas:

• Crash-relevant functions
• System monitoring functions
• Additional convenience functions.