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

MODEL 166 as of model year 2016 

MODEL 292 

Shows model 166.0 

Fig 1: Supplemental Restraint System Control Unit Component Location - Model 166

Courtesy of MERCEDES-BENZ USA

Location 

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

Tasks 

The Supplemental Restraint System control unit has the following tasks:

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

Model 166

as of model year 2016

with code 494 (US version)

Model 292

with code 494 (US version)

An accident data recorder is integrated in the Supplemental Restraint System control unit, which records relevant data before, during and after an accident. The data stored can be used to trace back the course of the accident.

Read in sensors and signals 

The input factors are read in via the following connections:

• Direct line 
• Seat occupancy LIN (LIN E2) (with CODE U10 (Automatic front passenger airbag shutoff)) 
• Chassis CAN 1 (CAN E1) 

Direct line 

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

• 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 rear door pressure sensor (B48/9)
• Right rear door pressure sensor (B48/10)
• Left B-pillar body acceleration sensor (B48/15)
• Right B-pillar body acceleration sensor (B48/16)
• Left front bumper pedestrian protection sensor (B151/1) (with CODE U60 (Active engine hood (pedestrian protection)))
• Center front bumper pedestrian protection sensor (B151/2) (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 belt buckle restraint system switch (S68/3)
• Front passenger belt buckle restraint system switch (S68/4)
• Front passenger seat position detection switch (S68/20) (with CODE 494 (USA version))

Seat occupancy LIN (with CODE U10 (Automatic front passenger airbag shutoff)) 

The status of the front passenger seat occupied recognition is sent by the weight sensing system (WSS) control unit (N110) (with CODE U10 (Automatic front passenger airbag shutoff)) via the seat occupancy LIN to the Supplemental Restraint System control unit.

Chassis CAN 1 

The following signals, among other things, are read in via chassis CAN 1:

• Terminal status of terminal 15
• National version
• Body variant
• Diagnosis request

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 (F32/3f88)
• Pyrotechnical separator (K88) (model 166.063)
• 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 2nd seat row emergency tensioning retractor squib (R12/6)
• Right 2nd seat row 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)
• Left windowbag squib (R12/22)
• Right windowbag squib (R12/23)
• Driver kneebag squib (R12/25)
• Emergency tensioning retractor squib, 3rd seat row at left (R12/35) (model 166.0 with CODE 847 (3rd seat row), model 166.8)
• Emergency tensioning retractor squib, 3rd seat row at right (R12/36) (model 166.0 with CODE 847 (3rd seat row), model 166.8)
• Driver anchor fitting tensioner squib (R12/37) (with CODE 494 (USA version))
• Front passenger anchor fitting tensioner squib (R12/38) (with CODE 494 (USA version))
• Left rear active engine hood squib (R12/49) (with CODE U60 (Active engine hood (pedestrian protection)))
• Right rear active engine hood squib (R12/50) (with CODE U60 (Active engine hood (pedestrian protection)))
• Inerting system squib (R12/69) (with engine 157, 276, 278 with code 2U8 (Alternative refrigerant))
• 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 SAM control unit (N10)
• Digital crash output to emergency call system control unit (N123/4) (with code 348 (Emergency call/assist system)) or to HERMES control unit (N112/9) (with code 360 (HERMES UMTS) or with code 362 (HERMES LTE))

Transmitting signals 

The following signals, among other things, are sent via chassis CAN 1:

• Crash signal
• Display fault messages request
• Driver belt buckle restraint system switch status
• Front passenger belt buckle restraint system switch status