Automatic Emergency Call

If the ISIS system detects a crash of sufficient severity, the emergency call by telephone is triggered automatically. The emergency call contains data from the navigation computer concerning the location of the vehicle. When the emergency call reaches the service provider, the location data is displayed on the Control Display.

Fig 1: Automatic Emergency Call Circuit Diagram (1 Of 2)

Courtesy of BMW OF NORTH AMERICA, INC.

There is a direct, serial, single-wire connection between the SIM and telephone. If the connection is disrupted or fails, the overall bus system is used to trigger the emergency call.

Fig 2: Automatic Emergency Call Circuit Diagram (2 Of 2)

Courtesy of BMW OF NORTH AMERICA, INC.

The telegram then goes from the SIM to the Central Gateway Module via the K-CAN to the Control Display and the MOST bus to the telephone. Once an emergency call has been triggered, it cannot be cancelled. To ensure that the emergency call has reached the provider, an acknowledgement is transmitted, and this is stored in the system. The service provider sets up a voice connection to the vehicle and receives confirmation of the emergency call. If no voice connection is set up or the occupants are unable to respond, the rescue services are notified automatically.