Trigger supplemental restraint system, function - GF91.60-P-2001CW
MODEL 204.0/2 up to Model Year 08
Function requirement
- Circuit 5R On
General information
The supplemental restraint system (SRS) constantly monitors the occupation status of the front passenger seat, the status of the front seat belts (buckled or not buckled) and adjusts its activation behavior by means of this information.
Front passenger seat occupation status
The supplemental restraint system control unit (N2/10) receives the corresponding information from the following components:
- Front passenger seat occupied recognition (B41/1) (without code (U18) Automatic child seat recognition (ACSR [AKSE]), not with
)
- Front passenger seat occupied recognition and ACSR (B48) (with code (U18) Automatic child seat recognition (ACSR [AKSE]))
- Weight Sensing System (WSS) control unit (N110) (only
Status of front seat belt
The left front seat belt buckle switch (S68/1) or the right front seat belt buckle switch (S68/2) is activated when the belt latch is inserted into the seat belt buckle. This is directly read in by the supplemental restraint system control unit.
The status of the rear seat belts does not have any influence on the activation behavior of the SRS.
Impact detection
The supplemental restraint system control unit measures the accelerations acting on the vehicle with the aid of its integrated sensor and the following sensors:
- Left sidebag sensor (A53)
- Right sidebag sensor (A54)
- Left frontal acceleration sensor (B48/1)
- Right frontal acceleration sensor (B48/2)
- Left front door pressure sensor (B48/7)
- Right front door pressure sensor (B48/8)
- Left rear door pressure sensor (B48/9)
(with code (293) Left and right rear sidebag)
- Right rear door pressure sensor (B48/10)
(with code (293) Left and right rear sidebag)
With the help of this sensor system, the SRS can make a distinction between the following types of accidents:
- Head-on collision
- Side-on collision
- Rear end collision
Function sequence in the event of a frontal impact
A frontal impact is recognized by the supplemental restraint system control unit via the signals from the following components:
- Sensor integrated in the supplemental restraint system control unit
- Left frontal acceleration sensor
- Right frontal acceleration sensor
The restraint equipment is activated depending on the severity of the impact, the occupation of the front passenger seat, and the status of the front seat belt.
The following squibs can be deployed (maximum):
- Driver ETR [GUS] squib (R12/1)
- Passenger ETR squib (R12/2)
- Front passenger airbag squib 1 (R12/4)
- Front passenger airbag squib 2 (R12/5)
- Left rear emergency tensioning retractor squib (R12/6)
- Right rear emergency tensioning retractor squib (R12/7)
- Driver airbag squib 1 (R12/13)
- Driver airbag squib 2 (R12/14)
- Driver kneebag squib (R12/25) (not
)
The following states are taken into account:
- Occupation status of the front passenger seat:
The supplemental restraint system control unit bases its decision on whether to suppress the 1st or 2nd stage of the front passenger airbag unit activation on the current occupation status.
- Driver seat belt buckle status:
If the left front seat belt buckle switch detects that a belt latch is not inserted into the seat belt buckle, then the driver airbag unit is deployed with advanced ignition timing instead of the driver emergency tensioning retractor unit.
- Front passenger seat belt buckle status:
If the right front seat belt buckle switch detects that a belt latch is not inserted into the seat belt buckle, then the front passenger airbag unit is deployed with advanced ignition timing instead of the front passenger emergency tensioning retractor unit.
This only applies, however, if the front passenger seat is known to be occupied. If not occupied, then neither the emergency tensioning retractor nor the front passenger airbag unit are deployed.
Function sequence in the event of a side impact
A side impact is recognized by the supplemental restraint system control unit via the signals from the following components:
- Sensor integrated in the supplemental restraint system control unit
- Left sidebag sensor
- Right sidebag sensor
- Left front door pressure sensor
- Right front door pressure sensor
- Left rear door pressure sensor
- Right rear door pressure sensor
The restraint equipment is deployed depending on the severity of the impact and the occupation of the front passenger seat.
The following squibs can be deployed (maximum):
- Driver ETR [GUS] squib
- Front passenger ETR [GUS] squib
- Left rear emergency tensioning retractor squib
- Right rear emergency tensioning retractor squib
- Driver sidebag squib (R12/9)
- Front passenger sidebag squib (R12/10)
- Left rear sidebag squib (R12/11)
(with code (293) Left and right rear sidebag)
- Right rear sidebag squib (R12/12)
(with code (293) Left and right rear sidebag)
- Left windowbag squib (R12/22)
- Right windowbag squib (R12/23)
The following status is taken into account:
- The supplemental restraint system control unit makes the decision on the deployment of the front passenger sidebag unit based on the current occupation of the front passenger seat.
Function sequence in the event of a rear end collision
A rear end collision is recognized by the supplemental restraint system control unit via the signals from the following components:
- Sensor integrated into the restraint systems control unit
- Left sidebag sensor
- Right sidebag sensor
- Left frontal acceleration sensor
- Right frontal acceleration sensor
The restraint equipment is deployed depending on the severity of the impact and the status of the front seat belts.
The following squibs can be deployed (maximum):
- Driver ETR [GUS] squib
- Front passenger ETR [GUS] squib
- Left rear emergency tensioning retractor squib
- Right rear emergency tensioning retractor squib
Actuation of:
- Driver seat NECK-PRO head restraint solenoid (Y24/12)
- Front passenger seat NECK-PRO head restraint solenoid (Y24/13)
The following states are taken into account:
- Driver seat belt buckle status:
If the left front seat belt buckle switch registers that a belt latch is not inserted into the seat belt buckle, then the driver emergency tensioning retractor unit is not activated.
- Front passenger seat belt buckle status:
If the right front seat belt buckle switch registers that a belt latch is not inserted into the seat belt buckle, then the front passenger emergency tensioning retractor unit is not activated.
In addition to triggering the corresponding restraint equipment, the supplemental restraint system control unit prompts the following procedures:
- Engine shutoff
- Signal via chassis CAN to the CDI control unit (N3/9) (with diesel engine) or the ME-SFI [ME] control unit (N3/10) (gasoline engine)
- Release of the door locks and lowering of the side windows
- Signal via chassis CAN to the front SAM control unit with fuse and relay module (N10/1) is transmitted via interior CAN to the left front door control unit (N69/1), the right front door control unit (N69/2), the left rear door control unit (N69/3), and the right rear door control unit (N69/4)
- Activation of the hazard warning function
- Signal via chassis CAN to the front SAM control unit is transmitted via interior CAN to the rear SAM control unit with fuse and relay module (N10/2)
- Activation of the pyrofuse
- Discrete signal for activation of pyrofuse 88 (F32f88) in the front electrical prefuse box (F32)
- Transmission of an emergency call
(with code (359) TELE AID emergency call system)
- Signal via chassis CAN to the front SAM control unit is transmitted via diagnostic CAN to the emergency call system control unit (N123/4); at the same time, a discrete signal is transmitted to the emergency call system control unit
| Electrical function diagram, supplemental restraint system (SRS) | PE91.60-P-2052-99FAA | ||
| Sidebag sensor component description | A53, A54 | GF91.60-P-4034CW | |
| Frontal acceleration sensor, component description | B48/1, B48/2 | GF91.60-P-4065CW | |
| Door pressure sensor, component description | B48/7, B48/8; B48/9, B48/10 (with code (293) Left and right rear sidebag) |
GF91.60-P-4061CW | |
| Supplemental restraint system control unit, component description | N2/10 | GF91.60-P-4068CW | |
| Rear SAM control unit with fuse and relay module, component description | N10/2 | GF54.21-P-6030CW | |
| Left front door control unit, component description | N69/1 | GF72.29-P-6001CW | |
| Right front door control unit, component description | N69/2 | GF72.29-P-6009CW | |
| Rear door control unit, component description | N69/3, N69/4 | GF72.29-P-6021CW | |
| Front emergency tensioning retractor component description | R12/1, R12/2 | GF91.60-P-4042CW | |
| Front passenger airbag component description | R12/4, R12/5 | GF91.60-P-4038CW | |
| Rear emergency tensioning retractor component description | R12/6, R12/7 | GF91.60-P-4043CW | |
| Driver/passenger sidebag, component description | R12/9, R12/10 | GF91.60-P-4039CW | |
| Rear sidebag component description | R12/11, R12/12 With code (293) Left and right rear sidebag |
GF91.60-P-4040CW | |
| Driver airbag component description | R12/13, R12/14 | GF91.60-P-4037CW | |
| Windowbag component description | R12/22, R12/23 | GF91.60-P-4041CW | |
| Kneebag, component description | R12/25 Without code (494) USA version, without code (460) Canada version |
GF91.60-P-4056CW | |
| Seat belt buckle switch, component description | S68/1, S68/2 | GF91.60-P-4045CW | |
| NECK-PRO head restraint solenoid, component description | Y24/12, Y24/13 | GF91.16-P-2031CW |