GF91.60-P-2001FL Deploy Supplemental Restraint System, Function

GF91.60-P-2001FL Deploy Supplemental Restraint System, Function

General function requirements
^ Circuit 15R On

The electronic ignition lock control unit (N73) transmits circuit status 15R via the chassis CAN (CAN E) to the supplement restraint system control unit (N2/10).

Deploying supplemental restraint system, general
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 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
^ Impact detection function sequence
^ Frontal impact function sequence
^ Side impact function sequence
^ Rear end collision function sequence
^ Rollover function sequence
^ Function sequence of 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))
- 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 supplemental restraint system is read in directly by the supplement restraint system control unit.

The status of the rear seat belts does not have any influence on the deployment behavior of the SRS.

Impact detection function sequence
The supplement restraint system control unit determines the acceleration acting on the vehicle with the aid of the following sensors:
- Integrated sensor
- 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 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

Frontal impact function sequence
A frontal impact is detected by the supplemental restraint system control unit via the signals from the following components:
- Integrated sensor
- 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:
- 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.

Side impact function sequence
A side impact is detected by the supplemental restraint system control unit via 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 (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) (with code (494) USA version)
- Front passenger pelvis airbag squib (R12/42) (with code (494 USA version)

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.

Rear end collision function sequence
A rear-end collision is detected by the supplemental restraint system control unit via 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 (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.

Rollover function sequence
A rollover is detected by the supplemental restraint system control unit via the integrated sensor. Only one roll-over around the longitudinal vehicle axis can be detected.

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 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
If an airbag is deployed, the supplemental restraint system control unit transmits an appropriate signal to the front SAM control unit via the chassis CAN.
The front SAM control unit starts the flasher function by outputting a flasher frequency to the interior CAN (CAN B) and actuates the following lamps:
- Left front turn signal lamp (E1e5)
- Right front turn signal lights (E2e5)

The following lamps are actuated as follows:
- Left outside mirror turn signal lamp (N69/1) by the left front door control (E6/5
- Right outside mirror turn signal lamp (N69/2) by the right front door control unit (E6/6)
- Left rear turn signal lamp and right rear turn signal (N10/2) by the right front door control unit E3e1 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
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. This sends the crash signal via interior CAN. The following central locking motors are then actuated as follows:
- Left front door control locking motor by left front door control unit (A85m1)
- Right front door central locking motor by right front door control unit (A85/1m1)
- Left rear door central locking motor (A85/3m1) by left rear door control unit (N69/3)
- Right rear door central locking motor (A85/4m1) by right rear door control unit (N69/4)

The central locking is unlocked after a waiting time of t = 8 to 11 s.

Function sequence for opening the side windows
The side windows are opened 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 with fuse and relay module. This sends the crash signal via interior CAN. The following power window motors are then actuated as follows:
- Left front door power window motor by left front door control unit (M10/3)
- Right front door power window motor by right front door control unit (M10/4)
- Left rear door power window motor (M10/5) by left rear door control unit
- Right rear door power window motor (M10/6) by right rear door control unit

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 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.

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 signals from the supplemental restraint system control unit via the chassis CAN)
- Status of driver door from left front door control unit
- Circuit status c. 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.