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Home >> Mercedes Benz >> 2012 >> S 350 BLUETEC (221.183) V6-3.0L DSL Turbo (642.868) >> Repair and Diagnosis >> Restraints and Safety Systems >> Seat Belt Systems >> Seat Belt Control Module >> Description and Operation

Seat Belt Control Module: Description and Operation



GF91.60-P-4048LE Restraint Systems Control Unit, Component Description


Component Identification:






Location
The restraint systems control unit is located on the center tunnel.

Task
The restraint systems control unit has the following tasks:
^ Reading in of sensors and signals
^ Evaluation of input factors
^ Actuation of components

Reading in of sensors and signals
The input factors are read in with the following connections:
^ Direct line
^ Chassis CAN (CAN E)

Direct line
The following sensors are read in via a direct line:
- 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 automatic child seat recognition (B48) (with code (U18) Automatic child seat recognition (AKSE)
- Driver-side frontal acceleration sensor (B48/1)
- Passenger-side frontal acceleration sensor (B48/2)
- Airbag system driver assist (B48/5)
- Airbag system front passenger assist (B48/6)
- Driver door pressure sensor (B48/7)
- Front passenger door pressure sensor (B48/8)
- Rear door pressure sensor, driver-side (B48/9) (model 221)
- Rear door pressure sensor, passenger-side (B48/10) (model 221)
- Driver seat belt buckle and seat belt warning switch (S68/1)
- Front passenger seat belt buckle and seat belt warning switch (S68/2)

The following signals are read in via a direct line:
- Circuit 15R
- Circuit 30
- Circuit 31

Chassis CAN
The following signals are transmitted by the relevant control unit via the interior CAN (CAN B) to the central gateway control unit (N93). This routes the signals via the chassis CAN to the restraint systems control unit:
- Status of seat occupied recognition from WSS control unit (Weight Sensing System) (N2/13) (model 221 with code (494) USA version up to 31.8.08)
- Status of seat occupied recognition from Weight Sensing System control system (WSS) (N110) (model 216 with code (494) USA version, model 221 with code (494) USA version as of 1.9.08)

The following signals are sent on model 221 as of 1.6.09 to the ESP control unit (N47-5) (without model 221.095/195) or to the regenerative braking system control unit (N30/6) (model 221.095/195) by the radar sensors control unit (SGR) (N62/1) (with code (233) DISTRONIC PLUS) via the vehicle dynamics CAN (CAN H).

The ESP control unit or regenerative braking system control unit sends the signals to the restraint system control unit via the chassis CAN:
- Relative speed in relation to opposing object
- Time until impact

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
Components are actuated with the following lines:
^ Direct line
^ Chassis CAN

Direct line
The following components are actuated via a direct line:
- Passenger airbag squib 1 (R12/4)
- Passenger airbag squib 2 (R12/5)
- Left rear ETR squib (R12/6)
- Right rear ETR squib (R12/7)
- Left rear sidebag squib (R12/11)
- Right rear sidebag squib (R12/12)
- Driver airbag squib 1 (R12/13)
- Driver airbag squib 2 (R12/14)
- Front left sidebag squib (R12/20)
- Front right side air bag squib (R12/21)
- Left rear windowbag squib (R12/22)
- Right rear windowbag squib (R12/23)
- Driver kneebag squib (R12/25) (with code (294) Kneebag)
- Drive buckle ETR squib (R46)
- Front passenger ETR squib (R46/1)
- Solenoid for NECK-PRO head restraint, driver (Y24/12) (model 221)
- Solenoid for NECK-PRO head restraint, passenger side (Y24/13) (model 221)
- Analog crash output to the to the ME control unit (N3/10) (wit gasoline engine) or to the CDI control unit (N3/9) (on model 221 with diesel engine)

Chassis CAN
The following components are actuated via the chassis CAN:
- ME control unit or CDI control unit (on model 221 with diesel engine) for switching off the engine by the central gateway control unit
- via the interior CAN, the stationary heater control unit (A6n1) (model 216 with code (228) Stationary heater) or the stationary heater or heater booster control unit (A6n1) (model 221 with code (228) Stationary heater) to switch off the stationary heater
- via the interior CAN and the upper control panel control unit (N72/1)) via the upper control panel LIN (LIN B3), the automatic child seat recognition airbag OFF indicator lamp (S6/2e1
- via the diagnostic CAN (CAN D) and additionally via a digital crash output, the emergency call system control unit (N123/4) (with code (494) US version) to trigger an emergency call
- via interior CAN, the rear control unit (N22/6) (model 216)
- Left door control unit (N69/1) (model 216) or Left front door control unit (N69/1) (model 221)
- Right door control unit (N69/2) (model 216) or Right front door control unit (N69/2) (model 221)
- Left rear door control unit (N69/3) (model 221)
- Right rear door control unit (N69/4) (model 221) for crash opening the power windows (EFH)





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