ETR Control Module with Airbag, Function

N2/2:

N2/2 (with Side Airbags):

The ETR control module with airbag (N2/2) has two integrated, redundant acceleration sensors for sensing:
- The deceleration acting in the longitudinal direction of the vehicle during a head-on collision
- The acceleration acting in the longitudinal direction of the vehicle during a rear-end collision
- The acceleration acting in the lateral direction of the vehicle during a side collision (on vehicles with side airbags).
- The switching states of the left and right seat belt buckle switches (on (USA) version and before 6/93)

The control module links all incoming signals from the airbag and emergency tensioning retractor system and triggers the airbags, side airbags and emergency tensioning retractors according to the signals received during a collision.

An additional safety sensor is integrated into the control module for protection against erroneous triggering during normal vehicle operation. This sensor has two switching states (actuated-not actuated) and is actuated only by deceleration caused by a front-end collision. It is connected in series into the triggering circuits for the driver and passenger airbags and conducts the full triggering current when they are triggered.

The safety sensor is not connected into the triggering circuits for the front left and right emergency tensioning retractors. However, its switching state is checked by the control module before triggering the emergency tensioning retractors. The emergency tensioning retractors are triggered only when it has been actuated by the deceleration present.

The safety sensor has no function for side collisions. Here an additional safety margin against erroneous triggering is achieved by checking the second (redundant) acceleration sensor.