Head-on collision, function - GF91.60-P-2006GZ

MODEL 164 with CODE (494) USA version up to Model Year 08

Sequence of emergency tensioning retractor activities in the event of moderately severe frontal impact for the driver and passenger-side

Fig 1: Identifying Emergency Tensioning Retractor Activities

Courtesy of MERCEDES-BENZ USA

Sequence of front airbag deployment in the event of severe frontal impact for the driver and passenger-side

Fig 2: Front Airbag Deployment Sequence

Courtesy of MERCEDES-BENZ USA

Moderately severe frontal impact (1st triggering stage)

If the 1st triggering threshold is exceeded in the event of a moderately severe head-on collision, only the seat belts are activated.

The restraint systems control unit (N2/7) registers medium deceleration via the driver-side frontal acceleration sensor (B48/1) or the passenger-side frontal acceleration sensor (B48/2) and activates the following squibs:

Driver ETR [GUS] squib (R12/1)
Passenger ETR squib (R12/2)
Left 2nd row ETR [GUS] squib (R12/6)
Right 2nd row ETR [GUS] squib (R12/7)
Left 3rd seat row emergency tensioning retractor squibs (R12/35)
Right 3rd seat row emergency tensioning retractor squibs (R12/36)

WSS (Weight Sensing System)

The seat occupied and child seat recognition is determined by the weight sensing system (WSS).

A weight measurement of the WSS (Weight Sensing System) control unit (N2/13) in the front passenger seat enables a weight class to be determined which is then sent to the restraint systems control unit. The restraint systems control unit uses the weight class to determine whether a suppression, a 1-stage or 2-stage triggering of the front passenger airbag is necessary. If a seat belt on the passenger-side is not engaged in the seat belt buckle, the restraint systems control unit registers this via the front passenger seat belt buckle and seat belt warning switch (S68/2) and does not trigger the front passenger ETR [GUS] squib.

There is no seat belt buckle scan for the left/right seats in the 2nd seat row and in the 3rd seat row; therefore, the left/right 2nd seat row emergency tensioning retractor squibs and the left/right 3rd seat row emergency tensioning retractor squibs are always triggered.

Severe head-on collision (2nd and 3rd triggering threshold)

If in the event of a severe frontal impact, the 2nd triggering stage is exceeded, then the seat belts and front airbags are activated. The restraint systems control unit registers severe deceleration via the driver or passenger-side frontal acceleration sensor and activates the following squibs:

Driver ETR [GUS] squib and front passenger ETR [GUS] squib
Left 2nd row ETR [GUS] squib and right 2nd row ETR [GUS] squib
Left/right 3rd row ETR [GUS] squibs
Driver airbag squib 1 (R12/13)
Passenger airbag squib 1 (R12/4)
Driver belt force limiter (R12/27)
Front passenger belt force limiter (R12/26)

If in the event of a severe frontal impact, the 3rd triggering stage is exceeded, then the restraint systems control unit activates the following squibs too:

Driver airbag squib 2 (R12/14)
Passenger airbag squib 2 (R12/5)

WSS (Weight Sensing System)

The seat occupied and child seat recognition is determined by the weight sensing system (WSS). A weight measurement in the front passenger seat enables a weight class to be determined and this is sent to the restraint systems control unit. The restraint systems control unit uses the weight class to determine whether a suppression, a 1-stage or 2-stage triggering of the front passenger airbag is necessary.

A seat belt on the driver or passenger-side that is not engaged in the seat belt buckle, is registered by the restraint systems control unit via the driver seat belt buckle and seat belt warning switch or the front passenger seat belt buckle and seat belt warning switch, whereupon the corresponding driver or passenger-side ETR [GUS] squib and the driver or passenger-side driver belt force limiters are not deployed.

In the event of a collision and when the corresponding triggering threshold is exceeded, an additional signal is transmitted to the emergency call system control unit (N123/4) by the restraint systems control unit and an automatic emergency call is completed

Driver-side/front passenger frontal acceleration sensor component description		GF91.60-P-4033GZ
WSS sensor (Weight Sensing System), component description		GF91.60-P-4036GZ
Driver airbag component description		GF91.60-P-4037GZ
Front passenger airbag component description		GF91.60-P-4038GZ
Front emergency tensioning retractor component description		GF91.60-P-4042GZ
Rear emergency tensioning retractor component description		GF91.60-P-4043GZ
Seat belt buckle switch, component description		GF91.60-P-4045GZ
WSS (Weight Sensing System) control unit, component description		GF91.60-P-4046GZ
Restraint systems control unit, component description		GF91.60-P-4048GZ
3rd seat row emergency tensioning retractor, component description	Model 164.8	GF91.60-P-4063GY