Function

The supplemental restraint systems control module (N2/7) uses the integrated acceleration sensors to sense
- the deceleration of the vehicle in the longitudinal direction during a front end collision,
- the acceleration affecting the vehicle in the longitudinal direction during a rear end collision,
- the acceleration affecting the vehicle in the lateral direction during a side collision

Moreover, the control module senses
- the switching states of the following belt buckles: Left front seat belt buckle/belt lock switch (S68/7), right front seat belt buckle, belt lock switch (S68/8), left rear seat belt buckle and seat belt wear convenience switch (S68/11) and right rear seat belt buckle and seat belt wear convenience switch (S68/12)
- momentary status of the passenger seat with the electronic evaluation circuitry of the seat occupied and child seat recognition sensor in front passenger seat (B48).

The supplemental restraint systems control module (N2/7) links all sensor signals and decides what airbag/side airbag and emergency tensioning retractors are to be triggered on the basis of the vehicle data stored in the control module to guarantee the best possible passenger protection.

To protect against erroneous actuation during normal driving operation, resulting from EMC influences, for example, an additional safety sensor is integrated into the control module. This sensor is a mechanical switch which is closed in the event of a crash in the longitudinal direction. In the event of a crash the entire triggering current for the driver and passenger airbag flows through the closed switch. The mechanical safety sensor is not integrated into the triggering circuits of the emergency tensioning retractors. However, its switching state is checked by the supplemental restraint systems control module (N2/7) before triggering the emergency tensioning retractors. Only when the safety sensor is actually actuated as a result of the deceleration are the emergency tensioning retractors actually triggered. In the event of a side collision the safety sensor has no function. Here a plausibility check in the control module prevent erroneous actuation.