LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mercedes Benz >> 2021 >> A220 Base >> Repair and Diagnosis (Single Page) >> Restraints >> Restraints Control Systems >> Seats, Bunks, Restraint Systems - 177 Chassis (1 Of 2) >> Basic Knowledge >> Deploy Supplemental Restraint System, Basic Function - GF91.60-P-1003A
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Deploy Supplemental Restraint System, Basic Function - GF91.60-P-1003A

Model All (4xWD) 

Model All (CAR) 

Overview 

This document contains the following information:

General 

The SRS evaluates various input factors and deploys the corresponding restraint equipment in the event of an accident.

Function requirement 

Function 

The restraint equipment is actuated depending on:

In the following table, component parts marked with "X" are those that can be ultimately triggered for the respective accident scenarios:

  Frontal impact Side impact Rear impact Rollover
Driver airbag X - - -
Passenger airbag X - - -
Kneebag X - - -
Center airbag (vehicles with center airbag) - X - -
Front side airbag - X - -
Rear passenger compartment side airbag (vehicles with side airbag in the rear) - X - -
Rear airbag (vehicles with tubular-structure airbag for rear passengers) X - - -
Cushionbag (vehicles with reclining rear seat) X - - -
Belt airbag (vehicles with belt airbag for rear passengers) X - - -
Window airbag X X - X
Front ETR X X X X
Rear emergency tensioning retractor X X X X
Front seat belt end-fitting tensioner (Canada version or USA version) X - - -
Front seat belt force limiter (Canada version, USA version or Japan version) X - - -
PRE-SAFE® Impulse (vehicles with driver seat belt buckle with integrated tensioning function) X - - -
PRE-SAFE® Impulse side (vehicles with PRE-SAFE® Impulse side) - X - -
Gas generator inerting system (vehicles with alternative refrigerant and spark-ignition engine) X - - -
12 V on-board electrical system battery pyrofuse (hybrid vehicles) X - - -
Pyrofuse, circuit 30c (vehicles with 48 V technology, hybrid or electric vehicles) X X X X

The following conditions are taken into account in the case of frontal impact: 

The rear airbags are only triggered if they have not been deactivated beforehand using the corresponding menu in the head unit.

The following conditions are taken into account in the event of a side impact: 

The following conditions are taken into account in the event of a rear impact: 

The following conditions are taken into account in the event of a vehicle rollover: 

Vehicles with alternative refrigerant and spark-ignition engine 

In the event of a severe frontal impact, the refrigerant lines of the air conditioning system may be damaged. The leaking refrigerant together with the ambient air forms a combustible mixture. The inerting system ensures that this refrigerant/air mixture is kept separated from the hot engine parts. The hot engine parts are also effectively cooled. The inert gas argon is stored in the inerting system's gas cylinder. The targeted release of inert gas at the appropriate hot spots can counteract the potential ignition of the refrigerant/air mixture.

Vehicles with 48 V technology, hybrid or electric vehicles 

In the event of an accident, the electric lines and components may be damaged. To avoid a fire hazard caused by a short circuit, the following pyrofuses are deployed:

  Function schematics     
  Function schematic, trigger Supplemental Restraint System Model 118, 177, 243, 247 PE91.60-P-2501-97A
    Model 167 Model 293 PE91.60-P-2501-97B
    Model 206, 254 PE91.60-P-2501-97E
    Model 213, 238, 257, 290 as of model year 2021 PE91.60-P-2501-97D
    Model 223 PE91.60-P-2501-97C
    Model 295, 296, 297 PE91.60-P-2501-97F
    Model 232 PE91.60-P-2501-97G
    Model 464 PE91.60-P-2501-97H
  Subsystems     
  Front passenger seat, seat occupancy recognition, basic function Model all (CAR) GF91.60-P-1006A
  Control units     
  Supplemental restraint system control unit, basic function   GF91.60-P-9890A 
  Components     
  Inerting system, basic function Model all (CAR)
with code 2U8 (Alternative refrigerant) with gasoline engine
GF86.10-P-2003A
  Seat belt end-fitting tensioner, basic function Model all (CAR) with code 460 (Canada version)
Model all (CAR)
with code 494 (US version)
GF91.40-P-2025A
  Seat belt buckle switch, basic function   GF91.60-P-2009A
  Seat position Hall sensor, basic function Model all (CAR) with code 460 (Canada version)
Model all (CAR)
with code 494 (US version)
GF91.60-P-2013A
  Pyrofuse, basic function Vehicles with code B01 (48V technology), hybrid vehicles, electric vehicles GF91.60-P-2014A
  Seat belt tensioner, basic function Model all (CAR) GF91.60-P-2015A
  Driver airbag, basic function   GF91.60-P-2020A
  Front passenger airbag, basic function   GF91.60-P-2021A
  Side airbag, basic function Model all (CAR) GF91.60-P-2022A
  Window airbag, basic function Model all (CAR) GF91.60-P-2023A
  Knee airbag, basic function Model all (CAR) GF91.60-P-2024A
  Belt airbag, basic function Model all (CAR)
with code 306 (Rear seat belt with integrated airbag)
GF91.60-P-2026A
  Cushionbag, basic function Model all (CAR)
with code 453 (Rear reclining seat)
GF91.60-P-2028A
  Center airbag, basic function Model all (CAR)
with code 325 (Center airbag)
GF91.60-P-2029A
  Rear airbag, basic function Model all (CAR)
with code 302 (Tubular structure airbag for rear occupants)
GF91.60-P-2030A
  Component descriptions     
  Acceleration sensor for vertical acceleration of body, component description Model 223 GF32.50-P-2003A
    Model 206 GF32.50-P-2003C
    Model 297 GF32.50-P-2003D
  Airbag squib, component description Model 223 GF91.60-P-0006A
    Model 243 GF91.60-P-0006B
    Model 206 GF91.60-P-0006C
    Model 297 GF91.60-P-0006D
  Engine hood lifter, component description Model 223 GF91.60-P-1000A
    Model 206 GF91.60-P-1000C
    Model 297 GF91.60-P-1000D
  PRE-SAFE (R) pulse squib, component description Model 223 GF91.60-P-1101A
    Model 206 GF91.60-P-1101C
    Model 297 GF91.60-P-1101D
  Driver/front passenger belt force limiter, component description Model 223
with code 460 (Canada version)
with code 562 (Driver seat belt buckle with integrated tensioning function)
Model 223
with code 494 (US version)
with code 562 (Driver seat belt buckle with integrated tensioning function)
GF91.60-P-4044A
    Model 243 GF91.60-P-4044B
    Model 206 GF91.60-P-4044C
    Model 297 GF91.60-P-4044D
  Emergency tensioning retractor component description Model 223 GF91.60-P-4058A
    Model 243 GF91.60-P-4058B
    Model 297 GF91.60-P-4058D
  Door pressure sensor, component description Model 223 GF91.60-P-4061A
    Model 243 GF91.60-P-4061B
    Model 206 GF91.60-P-4061C
    Model 297 GF91.60-P-4061D
  Frontal acceleration sensor, component description Model 223 GF91.60-P-4065A
    Model 243 GF91.60-P-4065B
    Model 206 GF91.60-P-4065C
    Model 297 GF91.60-P-4065D
  Seat belt tensioner squib, component description Model 223 GF91.60-P-4073A
    Model 206 GF91.60-P-4073C
  Supplemental restraint system control unit, component description Model 223 GF91.60-P-4080A
    Model 243 GF91.60-P-4080B
    Model 206 GF91.60-P-4080C
    Model 297 GF91.60-P-4080D