Front Impact

Medium Head-On Collision (1st Actuation Threshold):

Only the emergency tensioning retractors are activated.

The airbag control module (N2/7) registers medium deceleration (actuation threshold 1) resulting from a collision.

It sends an actuation pulse only to the driver ETR squib (R12/1) and front passenger ETR squib (R12/2) as well as to the left rear ETR squib (R12/6) and right rear ETR squib (R12/7) - if present-, because for this type of accident the restraint function of the seat belts in combination with the emergency tensioning retractors is sufficient to provide the best possible protection for the vehicle passengers.

On vehicles with front passenger seat occupied recognition sensor with automatic child seat recognition (B48) a check is made whether the front passenger seat is occupied. If the front passenger seat is not occupied the airbag and emergency tensioning retractor on the front passenger side is not actuated. This also applies when a child seat with transponder is mounted on the passenger seat, which is recognized by the control module, however, whose values are not programmed.

A seat belt buckle check is made (USA only). If the seat belts are not buckled the driver/passenger airbags are triggered when actuation threshold 1 is exceeded in order to provide sufficient protection for vehicle passengers whose seat belts are not buckled.

Severe Head-On Collision (2nd Actuation Threshold):

The airbag control module (N2/7) registers high deceleration of the vehicle due to a collision.

It transfers the actuation pulse to the driver AB squib (R12/3) and passenger AB squib (R12/8).

Parallel to this the emergency tensioning retractors are also actuated.

On vehicles with front passenger seat occupied recognition sensor with automatic child seat recognition (B48) a check is made whether the front passenger seat is occupied.

If the front passenger seat is not occupied the airbag, side airbag and emergency tensioning retractor on the front passenger side are not actuated. This also applies when a child seat with transponder is installed on the passenger seat1which is recognized by the control module, however, whose values are not programmed.