GF91.60-P-2012FQ Actuate Supplemental Restraint System, Function
GF91.60-P-2012FQ Actuate Supplemental Restraint System, Function
MODEL 218
Function requirements, general
^ Circuit 15R ON
The status of circuit 15R is sent by the electronic ignition lock control unit (N73) over the chassis CAN (CAN E) to the Supplemental Restraint System control unit (N2/10).
Actuate supplemental restraint system, general
The Supplemental Restraint System (SRS) constantly monitors the occupation status of the front passenger seat and the status of the front seat belts (buckled or not buckled) and uses this information to adjust its deployment.
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 frontal impact
^ Function sequence for side impact
^ Function sequence for rear end collision
^ Function sequence for rollover
^ Function sequence for additional functions in the event of a crash
Function sequence for detecting occupied status of front passenger seat
The Supplemental Restraint System control unit receives the corresponding information from the following components:
- Front passenger seat occupied recognition (B41/1) (without code (U18) Automatic child seat recognition (ACSR [AKSE]) and without code (494) USA version)
- Front passenger seat occupied recognition and ACSR (B48) (with code (U18) Automatic child seat recognition (ACSR [AKSE])
- WSS (Weight Sensing System) control unit (N110) (with code (494) USA version)
Without code (U18) Automatic child seat recognition (ACSR [AKSE]) the status of the seat occupied recognition does not influence the deployment behavior of the supplemental restraint system.
Function sequence for detecting status of front seat belts
The driver seat belt buckle restraint system switch (S68/3) or the front passenger seat belt buckle restraint system switch (S68/4) is actuated by the belt latch which is inserted into the seat belt buckle.
The status of the restraint system switch 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 deployment behavior of the SRS.
Function sequence for impact detection
The Supplemental Restraint System control unit determines the acceleration acting on the vehicle with the aid of the following sensors:
- Integrated 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)
These sensors enable the SRS to distinguish between the following types of impacts:
- Head-on collision
- Side-on collision
- Rear end collision
Function sequence for frontal impact
A frontal impact is detected by the Supplemental Restraint System control unit through the signals from the following components:
- Integrated sensors
- Left frontal acceleration sensor
- Right 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 seat belts.
The following squibs can be ignited (maximum):
- Driver ETR 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) (with code (294) Kneebag)
The following situations are taken into account:
- Occupied state of the front passenger seat:
The Supplemental Restraint System 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 status:
If the driver seat belt buckle restraint system switch detects that a belt latch is not inserted into the seat belt buckle, the driver airbag unit with advanced ignition timing is triggered instead of the driver emergency tensioning retractor unit.
- Front passenger seat belt buckle status:
If the front passenger seat belt buckle restraint system switch detects that a belt latch is not inserted into the seat belt buckle, the front passenger airbag unit with advanced ignition timing is triggered 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 for side impact
A side impact is detected by the Supplemental Restraint System control unit through the signals from the following components:
- Integrated sensor
- 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 activation of the restraint equipment takes place depending on the severity of the impact and occupation of the front passenger seat.
The following squibs can be ignited (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)
- Driver pelvis airbag squib (R12/41) (with code (291) PELVIS AIRBAG (PELVISBAG))
- Front passenger pelvis airbag squib (R12/42) (with code (291) PELVIS AIRBAG (PELVISBAG))
The following state is taken into consideration:
- The Supplemental Restraint System control unit makes a decision about triggering the front passenger sidebag unit based on the current occupation of the front passenger seat.
Function sequence for rear end collision
A rear-end collision is detected by the Supplemental Restraint System control unit through the signals from the following components:
- Integrated sensor
- Left sidebag sensor
- Right sidebag sensor
- Left frontal acceleration sensor
- Right 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 (maximum):
- Driver ETR [GUS] squib
- Front passenger ETR [GUS] squib
- Left rear emergency tensioning retractor squib
- Right rear emergency tensioning retractor squib
The following components are actuated additionally:
- Driver seat NECK-PRO head restraint solenoid (Y24/12)
- Front passenger seat NECK-PRO head restraint solenoid (Y24/13)
The following situations are taken into account:
- Driver seat belt buckle status:
If the driver seat belt buckle restraint systems switch detects that a belt latch is not inserted into the seat belt buckle, the driver emergency tensioning retractor unit is not triggered.
- Front passenger seat belt buckle status:
If the front passenger seat belt buckle restraint systems switch detects that a belt latch is not inserted into the seat belt buckle the front passenger emergency tensioning retractor unit is not triggered.
Function sequence for rollover
A rollover is detected by the Supplemental Restraint System control unit through the integrated sensors. Only one roll-over around the longitudinal vehicle axis can be detected.
The following squibs can be ignited (maximum):
- Driver ETR [GUS] squib
- Front passenger ETR [GUS] squib
- Left rear emergency tensioning retractor squib
- Right rear emergency tensioning retractor squib
The following situations are taken into account:
- Driver seat belt buckle status:
If the driver seat belt buckle restraint systems switch detects that a belt latch is not inserted into the seat belt buckle, the driver emergency tensioning retractor unit is not triggered.
- Front passenger seat belt buckle status:
If the front passenger seat belt buckle restraint systems switch detects that a belt latch is not inserted into the seat belt buckle, the front passenger emergency tensioning retractor unit is not triggered.
Function sequence of additional functions in the event of a crash
The additional functions in the event of a crash comprise the following subfunctions:
^ Function sequence for activation of hazard warning function
^ Function sequence for opening the central locking (CL [ZV])
^ Function sequence for opening the side windows
^ Function sequence for shutting off the engine
^ Function sequence for shutting off the stationary heater (STH) (with code (228) Stationary heater)
^ Function sequence for automatic emergency call (with code (359) TELE AID emergency call system)
^ Function sequence for activation of crash-active exit aid (with code (275) Memory package for electrically adjustable front seats)
Function sequence for activation of hazard warning function
The supplemental restraint system automatically activates the hazard warning flashing function in order to warn traffic coming from behind in the event of an accident.
The Supplemental Restraint System control unit sends an appropriate signal to the front SAM control unit over the chassis CAN. The front SAM control unit sends the flasher frequency over the interior CAN (CAN B) to the following control units:
- Left front door control unit (N69/1)
- Right front door control unit (N69/2)
- Rear SAM control unit with fuse and relay module (N10/2)
The hazard warning flashing function can be deactivated by the driver at any given time.
Detailed information on the hazard warning flasher function is available in the separate function description for the exterior lights.
Function sequence for opening the central locking
The central locking is unlocked automatically after a crash event has occurred. The crash signal is sent by the Supplemental Restraint System control unit over the chassis CAN to the front SAM control unit. It sends the crash signal over the interior CAN to the following control units:
- Rear SAM control unit
- Left front door control unit
- Right front door control unit
- Left rear door control unit (N69/3)
- Right rear door control unit (N69/4)
The central locking is unlocked after a waiting time of t = 8 to 11 s.
In the event of a rear end collision, the CL is immediately unlocked.
Detailed information on the CL is given in the separate function description for central locking.
Function sequence for opening the side windows
After a crash event has occurred, the side windows are automatically opened by s = 50 mm. The crash signal is sent by the Supplemental Restraint System control unit over the chassis CAN to the front SAM control unit with fuse and relay module (N10/1). It sends the crash signal over the interior CAN to the following control units:
- Left front door control unit
- Right front door control unit
- Left rear door control unit
- Right rear door control unit
Detailed information on opening the side windows is available in the separate function description for the power windows (EFH).
Function sequence for shutting off the engine
The engine is shut off automatically after a crash event has occurred. The crash signal is sent by the Supplemental Restraint System control unit over the chassis CAN to the CDI control unit (N3/9) (with diesel engine) or to the ME-SFI [ME] control unit (N3/10) (with gasoline engine). This then causes the engine to be shut off.
The crash signal is also sent over a direct line by the Supplemental Restraint System control unit to the CDI control unit or the ME-SFI [ME] control unit.
Function sequence for switching off the STH (with code (228) Stationary heater)
The STH is shut off automatically after a crash event has occurred.
The crash signal is sent by the Supplemental Restraint System control unit over the chassis CAN to the front SAM control unit. This sends the crash signal via interior CAN to the stationary heater control unit (A6n1) which initiates shutoff of the STH.
Function sequence for automatic emergency call (with code (359) TELE AID emergency call system)
An emergency call is made automatically after a crash event has occurred. The crash signal is sent by the Supplemental Restraint System control unit over the chassis CAN to the front SAM control unit. This then sends the crash signal over the diagnostic CAN (CAN D) to the emergency call system control unit (N123/4), which triggers an automatic emergency call.
The crash signal is also sent over a direct line from the Supplemental Restraint System control unit to the emergency call system control unit.
Detailed information on the automatic emergency call is available in the separate function description for the emergency call system.
Function sequence for activation of crash-active exit aid (with code (275) Memory package for electrically adjustable front seats)
After a crash, the steering column is automatically moved upward during the following actions:
- Driver door opened
- Removing transmitter key (A8/1) from electronic ignition lock control unit
The driver seat control unit (N32/1) receives the following information via the interior CAN:
- Crash signal from front SAM control unit (the front SAM control unit receives the crash signal from the Supplemental Restraint System control unit over the chassis CAN)
- Status of driver door from left front door control unit
- Circuit status of circuit 15C OFF from electronic ignition lock control unit
After the information is received, the driver seat control unit actuates upward adjustment of the steering column.
