Deploy supplemental restraint system, function - GF91.60-P-2001GM
MODEL 164.1 as of model year 2009/YoM 08 model refinement package
MODEL 164.8, 251.0/1 as of model year 2009/YoM 08
Function requirements, general
- Circuit 5R On
Triggering supplemental restraint system (SRS), general
The supplemental restraint system (SRS) constantly monitors the occupied status of the front passenger seat (with code (U18) Automatic child seat recognition (ACSR [AKSE]) or with code (494) USA version) as well as the status of the front seat belts (fastened or not fastened) and adapts its deployment response based on this information.
The trigger SRS function consists of the following subfunctions:
- Function sequence for detecting occupied status of front passenger seat
- Function sequence for detecting status of front seat belts
- Function sequence for impact detection
- Function sequence for detecting frontal impact
- Function sequence for detecting side impact
- Function sequence for detecting rear-end collision
- Function sequence for detecting rollover
Function sequence for detecting occupied status of front passenger seat
The restraint systems control unit (N2/7) receives the corresponding information from the following components:
- Front passenger seat occupied recognition and automatic child seat recognition (B48) (with code (U18) Automatic child seat recognition (ACSR [AKSE]))
- WSS (Weight Sensing System) control unit (N2/13) (with code (494) USA version)
Function sequence for detecting status of front seat belts
The driver seat belt buckle and seat belt reminder warning switch (S68/1) or the front passenger seat belt buckle and seat belt reminder warning switch (S68/2) is actuated by the belt latch which is inserted into the seat belt buckle. This is read in directly by the restraint systems control unit.
For model 164 (without code (494) USA version and without code (498) Japan version) the seat belt buckles for the 2nd seat row are also equipped with a seat belt buckle query. However, this is only used for the status indication in the instrument cluster (A1) and does not affect the triggering characteristic of the SRS in any way.
This means that in the event of a crash the emergency tensioning retractors for the 2nd and 3rd seat row are also deployed even if the belt latches are not inserted.
Function sequence for impact detection
The restraint systems control unit determines the acceleration acting on the vehicle with the aid of its integrated sensor and the following sensors:
- Drive sidebag sensor (A53)
- Front passenger sidebag sensor (A54)
- Driver-side frontal acceleration sensor (B48/1)
- Passenger-side frontal acceleration sensor (B48/2)
- Driver door pressure sensor (B48/7)
- Front passenger door pressure sensor (B48/8)
- Rear door pressure sensor, driver-side (B48/9) (with code (293) Left and right rear sidebag)
- Rear door pressure sensor, passenger-side (B48/10) (with code (293) Left and right rear sidebag)
With the aid of this sensor system, the SRS is able to distinguish between the following types of impacts:
- Head-on collision
- Side-on collision
- Rear end collision
Function sequence for detecting frontal impact
A frontal impact is detected by the restraint systems control unit via the signals from the following components:
- Integrated sensor in the restraint systems control unit
- Driver-side frontal acceleration sensor
- Passenger-side frontal acceleration sensor
The restraint equipment is deployed depending on the severity of the impact, the occupation of the front passenger seat, and the status of the front seat belts.
The following maximum number of squibs can be ignited:
- Driver emergency tensioning retractor squib (R12/1) (model 251 as of 1.8.10)
- Front passenger emergency tensioning retractor squib (R12/2) (model 251 as of 1.8.10)
- Passenger airbag squib 1 (R12/4)
- Passenger airbag squib 2 (R12/5)
- Left 2nd row emergency tensioning retractor squib (R12/6)
- Right 2nd row emergency tensioning retractor squib (R12/7)
- Driver airbag squib 1 (R12/13)
- Driver airbag squib 2 (R12/14)
- Driver kneebag squib (R12/25) (model 164 with code (294) Kneebag)
- Pyrotechnical separating element (K88) (with model 164.195 or model 164.1 with engine 272 as of 1.7.09 or model 164.8 with engine 642 or model 164.8 with engine 273 as of 1.7.09)
- Left 3rd seat row emergency tensioning retractor squib (R12/35) (for model 251 and for model 164.8 with code (845) 3rd seat row folding down electrically)
- Right 3rd seat row emergency tensioning retractor squib (R12/36) (for model 251 and for model 164.8 with code (845) 3rd seat row folding down electrically)
- Driver buckle emergency tensioning retractor squib (R46) (model 251 up to 31.7.10; model 164)
- Front passenger buckle emergency tensioning retractor squib (R46/1) (model 251 to 31.7.10; model 164)
The following situations are taken into account:
- Occupied state of the front passenger seat:
The restraint systems control unit uses the current occupancy to decide whether to suppress the front passenger airbag unit or to use 1-stage or 2-stage deployment.
- Driver seat belt buckle and seat belt reminder warning status:
If the driver seat belt buckle and seat belt reminder warning switch detects a belt latch that is not inserted into the seat belt buckle, instead of the driver buckle emergency tensioning retractor (model 164; model 251 up to 31.7.10) or the driver emergency tensioning retractor unit (model 251 as of 1.8.10) the driver airbag unit with advanced ignition timing is triggered.
- Front passenger seat belt buckle and seat belt reminder warning status:
If the front passenger seat belt buckle and seat belt reminder warning switch detects a belt latch that is not inserted into the seat belt buckle, instead of the front passenger buckle emergency tensioning retractor (model 164; model 251 up to 31.7.10) or the front passenger emergency tensioning retractor unit (model 251 as of 1.8.10) the front passenger airbag unit with advanced ignition timing is triggered.
This only applies, however, if the front passenger seat is known to be occupied. If the seat is unoccupied, neither the emergency tensioning retractor, the buckle emergency tensioning retractor nor the front passenger airbag unit are triggered.
Function sequence for detecting side impact
A side impact is detected by the restraint systems control unit via the signals from the following components:
- Integrated sensor in the restraint systems control unit
- Driver sidebag sensor
- Front passenger sidebag sensor
- Driver door pressure sensor
- Front passenger door pressure sensor
- Rear door pressure sensor, driver-side (with code (293) Left and right rear sidebag)
- Rear door pressure sensor, passenger-side (with code (293) Left and right rear sidebag)
The restraint equipment is deployed depending on the severity of the impact, the occupation of the front passenger seat, and the status of the front seat belts.
The following maximum number of squibs can be ignited:
- Driver emergency tensioning retractor squib (model 251 as of 1.8.10)
- Front passenger emergency tensioning retractor squib (model 251 as of 1.8.10)
- Driver buckle emergency tensioning retractor squib (model 251 up to 31.7.10; model 164)
- Front passenger buckle emergency tensioning retractor squib (model 251 to 31.7.10; model 164)
- Left 2nd row ETR [GUS] squib
- Right 2nd row ETR [GUS] squib
- Left 3rd seat row emergency tensioning retractor squib (for model 251 and for model 164.8 with code (845) 3rd seat row folding down electrically)
- Right 3rd seat row emergency tensioning retractor squib (for model 251 and for model 164.8 with code (845) 3rd seat row folding down electrically)
- Driver sidebag squib (R12/9)
- Front passenger sidebag squib (R12/10)
- Left sidebag squib for 2nd seat row (R12/11) (with code (293) Left and right rear sidebag)
- Right sidebag squib for 2nd seat row (R12/12) (with code (293) Left and right rear sidebag)
- Left windowbag squib (R12/16)
- Right windowbag squib (R12/17)
The following state is taken into consideration:
- The restraint systems control unit makes its decision regarding triggering the front passenger sidebag unit based on the current occupancy of the front passenger seat.
Function sequence for detecting rear-end collision
A rear end collision is detected by the restraint systems control unit via the signals from the following components:
- Integrated sensor in the restraint systems control unit
- Driver sidebag sensor
- Front passenger sidebag sensor
- Driver-side frontal acceleration sensor
- Passenger-side frontal acceleration sensor
The activation of the restraint equipment takes place depending on the severity of the impact and the status of the front seat belts.
The following squibs can be ignited (at most):
- Driver emergency tensioning retractor squib (model 251 as of 1.8.10)
- Front passenger emergency tensioning retractor squib (model 251 as of 1.8.10)
- Driver buckle emergency tensioning retractor squib (model 251 up to 31.7.10; model 164)
- Front passenger buckle emergency tensioning retractor squib (model 251 up to 31.7.10; model 164)
- Left 2nd row ETR [GUS] squib
- Right 2nd row ETR [GUS] squib
- Left 3rd seat row emergency tensioning retractor squib (for model 251 and for model 164.8 with code (845) 3rd seat row folding down electrically)
- Right 3rd seat row emergency tensioning retractor squib (for model 251 and for model 164.8 with code (845) 3rd seat row folding down electrically)
Actuation also takes place over the:
- Driver NECK-PRO head restraint solenoid (Y24/12)
- Front passenger NECK-PRO head restraint solenoid (Y24/13)
The following situations are taken into account:
- Driver seat belt buckle and seat belt reminder warning status:
If the driver seat belt buckle and seat belt reminder warning switch detects a belt latch that is not inserted into the seat belt buckle, the driver buckle emergency tensioning retractor (model 164; model 251 up to 31.7.10) or the driver emergency tensioning retractor unit (model 251 as of 1.8.10) is not triggered.
- Front passenger seat belt buckle and seat belt reminder warning status:
If the front passenger seat belt buckle and seat belt reminder warning switch detects a belt latch that is not inserted into the seat belt buckle, the front passenger buckle emergency tensioning retractor (model 164; model 251 up to 31.7.10) or the front passenger emergency tensioning retractor unit (model 251 as of 1.8.10) is not triggered.
Function sequence for detecting rollover
A rollover is detected by the restraint systems control unit via the integrated sensor.
The following maximum number of squibs can be ignited:
- Driver emergency tensioning retractor squib (model 251 as of 1.8.10)
- Front passenger emergency tensioning retractor squib (model 251 as of 1.8.10)
- Driver buckle emergency tensioning retractor squib (model 251 up to 31.7.10; model 164)
- Front passenger buckle emergency tensioning retractor squib (model 251 up to 31.7.10; model 164)
- Left 2nd row ETR [GUS] squib
- Right 2nd row ETR [GUS] squib
- Left 3rd seat row emergency tensioning retractor squib (for model 251 and for model 164.8 with code (845) 3rd seat row folding down electrically)
- Right 3rd seat row emergency tensioning retractor squib (for model 251 and for model 164.8 with code (845) 3rd seat row folding down electrically)
The following situations are taken into account:
- Driver seat belt buckle and seat belt reminder warning status:
If the driver seat belt buckle and seat belt reminder warning switch detects a belt latch that is not inserted into the seat belt buckle, the driver buckle emergency tensioning retractor (model 164; model 251 up to 31.7.10) or the driver emergency tensioning retractor unit (model 251 as of 1.8.10) is not triggered.
- Front passenger seat belt buckle and seat belt reminder warning status:
If the front passenger seat belt buckle and seat belt reminder warning switch detects a belt latch that is not inserted into the seat belt buckle, the front passenger buckle emergency tensioning retractor (model 164; model 251 up to 31.7.10) or the front passenger emergency tensioning retractor unit (model 251 as of 1.8.10) is not triggered.
| Electrical function schematic for deployment of supplemental restraint system (SRS) | Model 164 | PE91.60-P-2053-97MAA | |
| Model 251 | PE91.60-P-2053-97RAA | ||
| Component description for instrument cluster | A1 Model 251, model 164 (except 164.195) |
GF54.30-P-6000GM | |
| Model 164.195 * for USA only |
GF54.30-P-6000GQH | ||
| Component description for restraint systems control unit | N2/7 | GF91.60-P-4048GM | |
| Component description for Weight Sensing System (WSS) control unit | N2/13 With code (494) USA version |
GF91.60-P-4046GMU |