Supplemental Restraint System Control Unit, Component Description - GF91.60-P-4080FH

Model 238 

Up To Model Year 2021 

Location 

The Supplemental Restraint System control unit is located on the transmission tunnel.

Tasks 

The Supplemental Restraint System control unit has the following tasks:

• Reading in of sensors and signals 
• Evaluation of input factors 
• Actuation of components 
• Transmitting signals 

A sensor unit integrated into the supplemental restraint system control unit detects the turn rate, lateral and longitudinal acceleration of the vehicle.

Reading in of sensors and signals 

The input factors are read in via the following connections:

• Direct line 
• Seat occupied recognition LIN (LIN E2) 
• User interface CAN (CAN HMI) 

Direct line 

The signals from the following sensors are read in via direct lines:

• Left sidebag sensor (A53)
• Right sidebag sensor (A54)
• Front passenger seat occupancy recognition (B41/1) (except CODE U10 (Automatic front passenger airbag shutoff))
• 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 front bumper pedestrian protection sensor (B151/1) (with CODE U60 (Active engine hood (pedestrian protection)))
• Right front bumper pedestrian protection sensor (B151/3) (with CODE U60 (Active engine hood (pedestrian protection)))
• Driver seat belt buckle switch (S68/3)
• Front passenger seat belt buckle switch (S68/4)
• Driver seat position detection switch (S68/19) (with CODE 494 (USA version) or CODE 460 (Canada version))
• Front passenger seat position detection switch (S68/20) (with CODE 494 (USA version) or CODE 460 (Canada version))

Seat occupied recognition LIN 

The Weight Sensing System (WSS) control unit (N110) (with code U10 (Automatic front passenger airbag deactivation)) sends the occupancy status of the front passenger seat over the seat occupancy LIN to the supplemental restraint system control unit.

User interface CAN 

The following signals are read in via the user interface CAN among other things:

• Status of the left rear belt buckle switch (S68/11)
• Status of the right rear belt buckle switch (S68/12)
• Status of collision recognition (with code 239 (DISTRONIC Distance Pilot) or code 258 (COLLISION PREVENTION ASSIST) or code 23P (Driving Assistance package))

Evaluation of input factors 

The input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.

Actuation of components 

The following components are actuated via direct lines:

• Pyrofuse (F63) (engine 264 with code B01 (48V technology))
• Driver emergency tensioning retractor squib (R12/1)
• Front passenger emergency tensioning retractor 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 sidebag squib (R12/9)
• Front passenger sidebag squib (R12/10)
• Sidebag squib in left rear (R12/11) (with CODE 293 (sidebags in rear))
• Sidebag squib in right rear (R12/12) (with CODE 293 (sidebags in rear))
• Driver airbag squib 1 (R12/13)
• Driver airbag squib 2 (R12/14) (with code 460 (Canada version) or code 494 (USA version))
• Left windowbag squib (R12/22) (model 238.3)
• Right windowbag squib (R12/23) (model 238.3)
• Driver kneebag squib (R12/25)
• Front passenger belt force limiter (R12/26) (with code 494 (USA version) or code 460 (Canada version) or code 498 (Japan version))
• Driver belt force limiter (R12/27) (with code 494 (USA version) or code 460 (Canada version) or code 498 (Japan version))
• Driver anchor fitting tensioner squib (R12/37) (with CODE 494 (USA version) or CODE 460 (Canada version))
• Front passenger anchor fitting tensioner squib (R12/38) (with CODE 494 (USA version) or CODE 460 (Canada version))
• Left headbag squib (R12/39) (model 238.4)
• Right headbag squib (R12/40) (model 238.4)
• Front passenger airbag bleed valve squib (R12/44) (with code 460 (Canada version) or code 494 (USA version))
• Left active engine hood squib (R12/49) (with CODE U60 (Active engine hood (pedestrian protection)))
• Right active engine hood squib (R12/50) (with CODE U60 (Active engine hood (pedestrian protection)))
• Left roll bar squib (R12/61) (model 238.4)
• Right roll bar squib (R12/62) (model 238.4)
• Refrigerant inerting squib (R12/69) (gasoline engine)
• Analog crash output to the CDI control unit (N3/9) (diesel engine) or to the ME-SFI [ME] control unit (N3/10) (gasoline engine)
• Analog crash output to front SAM control unit (N10/6)
• Electric steering lock control unit (N26/5) (transmission 725)

Transmitting signals 

The signals are transmitted via the following connections:

• User interface CAN 
• Vehicle dynamics CAN (CAN H) 

User interface CAN 

The following signals are sent via the user interface CAN among other things:

• Crash signal
• Display fault message request
• Status of driver belt buckle switch
• Status of front passenger belt buckle switch

Vehicle dynamics CAN 

The following signals, among others, are sent via the vehicle dynamics CAN:

• Turn rate
• Lateral acceleration
• Longitudinal acceleration

Wiring diagram for Supplemental Restraint System control unit

PE91.60-P-2106-97DCA