GF91.60-P-2001CE Deploy Supplemental Restraint System, Function
GF91.60-P-2001CE Deploy Supplemental Restraint System, Function
Function requirements, general
^ Circuit 15R ON
The electronic ignition lock control unit (N73) provides the status of circuit 15 on the chassis CAN
(CAN E).
Triggering supplemental restraint system (SRS), general
The supplemental restraint system constantly monitors the occupation status of the front passenger seat, the status of the front seat belts (buckled or not buckled) and uses this information to adjust its deployment.
Deploying the SRS comprises 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
^ Actuating SRS function sequence in event of frontal impact
^ Actuating SRS function sequence in event of side impact
^ Actuating SRS function sequence in event of rear-end collision
^ Function sequence for actuation SRS in event of rollover (on model 204.9 with code (494) USA version)
^ 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 (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]) and without code (494) USA version)
- Front passenger seat occupied recognition and ACSR (AKSE) (B48) (with code (U18) Automatic child seat recognition (ACSR [AKSE]) and without code (494) USA version)
- WSS (Weight Sensing System) control unit (N110) (with code (494) USA version)
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. This is read in directly 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 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)
This sensor system enables the SRS to distinguish between the following types of impacts:
- Head-on collision
- Side-on collision
- Rear end collision
Actuating SRS function sequence in event of frontal impact
A frontal impact is detected by the supplemental restraint system control unit via the signals from the following components:
- Integrated sensor in supplemental restraint system control unit
- 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 front seat belts.
The following squibs can be ignited (at most):
- 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) (with code (294) Kneebag)
The following situations are taken into account:
- 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.
- 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.
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 triggered.
Actuating SRS function sequence in event of side impact
A side impact is detected by the supplemental restraint system control unit via the signals from the following components:
- Integrated sensor in 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 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 (at most):
- 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) (model 204.0/9 with code (494) USA version)
- Passenger pelvis airbag squib (R12/42) (model 204.0/9 with code (494) USA version)
The supplemental restraint system control unit bases its decision with regard to triggering the front passenger sidebag unit on whether the front passenger seat is occupied or not.
Actuating SRS function sequence in event of rear-end collision
A rear-end collision is detected by the supplemental restraint system control unit via the signals from the following components:
- Integrated sensor in supplemental restraint system control unit
- 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 (at most):
- 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 also actuated:
- 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 actuation SRS in event of rollover (on model 204.9 with code (494) USA version)
A rollover is detected by the supplemental restraint system control unit via the integrated sensor.
The following squibs can be ignited (at most):
- 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 triggering the pyrofuse
^ Function sequence for automatic emergency call (with code (359) TELE AID emergency call system)
^ Function sequence for crash-active exit aid (with code (275) Memory package (driver seat, steering column, mirror)
Function sequence for activation of hazard warning function
The hazard warning function is activated automatically after a crash event has occurred. This is intended to warn other road users of the accident vehicle early. The crash signal is sent by the supplemental restraint system control unit over the chassis CAN (CAN E) to the front SAM control unit with fuse and relay module (N10/1).
This then actuates the following components directly:
- Left front turn signal lamp (E1e5)
- Right front turn signal lights (E2e5)
The front SAM control unit transmits the crash signal via interior CAN. The following lamps are then actuated as follows:
- By the left front door control unit (N69/1):
- Left outside mirror turn signal lamp (E6/5)
- By the right front door control unit (N69/2):
- Right outside mirror turn signal lamp (E6/6)
- By the rear SAM control unit with fuse and relay module (N10/2):
- Left rear turn signal light (E3e1)
- Right rear turn signal light (E4e1)
The hazard warning function can be deactivated at any time by pressing the hazard warning flasher switch (S6/1s1).
Function sequence for opening the central locking (CL [ZV])
The CL [ZV] is unlocked automatically after a waiting time of t = 8 s to t = 11 s following the occurrence of a crash event. This is intended to allow rescue of the vehicle occupants from the outside by the rescue personnel.
The crash signal is sent by the supplemental restraint system control unit over the chassis CAN to the front SAM control unit, this then forwards the crash signal over the interior CAN. The following central locking motors are then actuated as follows:
- By the left front door control unit:
- Left front door central locking motor (A85m1)
- By the right front door control unit:
- Right front door central locking motor (A85/1m1)
- By the left rear door control unit (N69/3):
- Left rear door central locking motor (A85/3m1)
- By the right rear door control unit (N69/4):
- Right rear door central locking motor (A85/4m1)
Function sequence for opening the side window
The side windows are opened automatically after a crash event has occurred. The purpose is to speed up extraction of the smoke particles generated by the pyrotechnical restraint equipment. 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. The following power window motors are then actuated as follows:
- By the left front door control unit:
- Left front door power window motor (M10/3)
- By the right front door control unit:
- Right front door power window motor (M10/4)
- By the left rear door control unit:
- Left rear door power window motor (M10/5)
- By the right rear door control unit:
- Right rear door power window motor (M10/6)
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) (for diesel engine) or to the ME-SFI [ME] control unit (N3/10) (for gasoline engine). This then causes the engine to be shut off.
Function sequence for triggering the pyrofuse
After a crash event occurs, the pyrofuse 88 (F32f88) in the front prefuse box (F32) is activated. The supplemental restraint system control unit actuates the pyrofuse 88 directly.
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.
Function sequence for activating crash-active exit aid With code (275) Memory package (driver seat, steering column, mirrors)
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 signals from the supplemental restraint system control unit via the chassis CAN)
- Status of driver door from left front door control unit
- Circuit status of clamp 15C OFF from electronic ignition lock control unit
After receiving the information, the driver seat control unit actuates the steering column adjustment up/down motor (M20/2) to adjust the steering column upward.
