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

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

Course of the emergency tensioning retractor activities for the driver and passenger side in the event of a moderately severe head-on collision

Fig 1: Identifying Emergency Tensioning Retractor Activities (Driver And Passenger Side)

Courtesy of MERCEDES-BENZ USA

Sequence of emergency tensioning retractors activities during a severe head-on collision for driver and front passenger side.

Fig 2: Emergency Tensioning Retractors Activities Sequence (Driver And Front Passenger Side)

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)

Seat occupied recognition sensor

If the front passenger seat occupied and child seat recognition sensor (B48) recognizes that the front passenger seat is not occupied or that a child seat is properly installed, the triggering function of the front passenger airbag is locked.

If the front passenger seat is occupied by a person, the pressure load of the seat area increases. This pressure load is sensed by the integrated force sensing resistors in the seat cushion and allocated to the corresponding weight classification. Depending upon the weight classification, a signal is transmitted to the restraint systems control unit and evaluated. 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.

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 a drastic deceleration via the driver-side or front passenger frontal acceleration sensor and activates the following squibs:

Driver and front passenger ETR [GUS] squib
Left 2nd row rear ETR [GUS] squib and right 2nd row rear 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)

If the seat belt on the driver or passenger side is not engaged in the seat belt buckle, then this fact 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, and the corresponding driver or front passenger ETR [GUS] squib and the driver or front passenger belt force limiter are triggered with different (accelerated) ignition times.

Seat belt buckle scan up to production period 31.05.06

If the left rear seat belt buckle switch (S68/11) and right rear seat belt buckle switch (S68/12), left 3rd seat row seat belt buckle switch (S68/16) (model 164.8) and right 3rd seat row seat belt buckle switch (S68/17) (model 164.8) signal that a seat belt has not been engaged, then the respective emergency tensioning retractors are not triggered by the restraint systems control unit.

Seat belt buckle scan as of production period 01.06.06

If the driver seat belt buckle and seat belt warning switch, front passenger seat belt buckle and seat belt warning switch signal that a seat belt has not been engaged, then the respective emergency tensioning retractors are not triggered by the restraint systems control unit.

There is no seat belt buckle scan for the 2nd seat row at left/right and seat belt buckle scan for the 3rd seat row at left/right (model 164.8). The emergency tensioning retractors for the 2nd and 3rd seat rows are triggered if the latch plate is not inserted.

Supplemental restraint system (SRS), function		GF91.60-P-0002GZE
Driver-side/front passenger frontal acceleration sensor component description		GF91.60-P-4033GZ
Seat occupied recognition with automatic child seat recognition, component description		GF91.60-P-4035GZ
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
Restraint systems control unit, component description		GF91.60-P-4048GZ
Rear seat belt buckle switch component description		GF91.60-P-4054GZ
3rd seat row emergency tensioning retractor, component description	Model 164.8	GF91.60-P-4063GY