Specifications

The airbag and belt tensioner system fitted to the Mercedes B-Class consists of:

• driver and front passenger airbags,
• front side airbags,
• front belt tensioners,
• curtain airbags (optional),
• rear belt tensioners,
• rear side airbags (optional).

Airbags and belt tensioners

DRIVER AIRBAG

It is located in the steering wheel; its cover forms the outer surface of the hub cover. It has two-stage deployment.

After the driver airbag has deployed, fit a new airbag, a new steering wheel and its fixing bolt, and the trim panel that holds the stalk switches.

PASSENGER AIRBAG

It is located under the dashboard, in front of the passenger. It is accessible after removing the glove box.

After the passenger airbag has deployed, fit a new airbag and replace the dashboard.

FRONT SIDE AIRBAGS

They are located in the front seats.

REAR SIDE AIRBAGS

They are fixed to the rear pillar at the rear door striker.

CURTAIN AIRBAGS

They are located in the roof rail on each side of the vehicle. They are accessible after removing the roof lining trim and the front, centre and rear pillar trim panels.

Location of airbag and belt tensioner system components

For the parts list, see 'Airbag and belt tensioner system diagram'.

1. 1
   Driver airbag module
2. 2
   Passenger airbag module
3. 3
   Front side airbag unit
4. 4
   Front seat belt retractor unit
5. 5
   Rear seat belt retractor unit
6. 6
   Rear side airbag unit (with optional Sidebag on rear left and right)
7. 7
   Front seat belt buckle retractor unit
8. 8
   Rear seat belt buckle retractor unit
9. 9
   Window airbag unit (with optional Windowbag).

Airbag and belt tensioner management

CONTROL UNIT

It is located in the passenger compartment, under the floor console, and controls the deployment of the airbag(s) and belt tensioner(s) using various sensors.

Pin assignment of connector A (Fig.1)

Pin assignment of connector B (Fig.1)

Pin layout of airbag and belt tensioner control unit connectors Fig. 1

Airbag and belt tensioner system diagram

A. Vehicles up to 30/11/05
B. Vehicles from 1/12/05
CAN-B. Body CAN data bus
CAN-C. Engine CAN data bus

Signals:

1. 1
   Terminal status
2. 2
   Crash signal
3. 3
   Passenger seat installed (with Maxi-Vario pack option)
4. 4
   Power supply voltage
5. 5
   Front passenger seat occupancy status
6. 6
   Information and warning messages
7. 7
   Impact detection
8. 8
   Trigger restraint systems
9. 9
   Igniter monitoring
10. 10
    Seat belt buckle monitoring
11. 11
    Activate hazard warning lights
12. 12
    Unlock central locking
13. 13
    Stop engine
14. 14
    Passenger airbag deactivation indicator
15. 15
    Activate emergency call (with TELE AID emergency call system option)
16. 16
    Engine cut-off (from 1/06/06)

Components:

A1. Instrument cluster
A53/1. Side airbag and window airbag sensor, left
A54/1. Side airbag and window airbag sensor, right
B41/1. Front passenger seat occupancy detection (without automatic child seat detection (AKSE) option)
B48. Front passenger seat occupancy and child seat detection (with automatic child seat detection (AKSE) option)
B48/1. Driver frontal acceleration sensor (USA only)
B48/2. Front passenger frontal acceleration sensor (USA only)
N2/7. Restraint systems control unit
N3/9. CDI control unit (diesel engine)
N3/10. ME control unit (petrol engine)
N10. SAM control unit
N18. HAU control unit and control panel (without automatic air conditioning and without comfort automatic air conditioning option)
N22. KLA control unit and control panel (with automatic air conditioning option)
N22/7. KLA comfort control unit and air conditioning control (with comfort automatic air conditioning option)
N69/1. Front left door control unit
N69/2. Front right door control unit
N69/3. Rear left door control unit (with rear electric window option)
N69/4. Rear right door control unit (with rear electric window option)
N73. EZS control unit
N93. Central gateway control unit (until 31/05/06)
N123/4. Emergency call system control unit (with TELE AID emergency call system option)
R12/1. Seat belt pretensioner igniter, driver
R12/2. Seat belt pretensioner igniter, passenger
R12/4. Passenger airbag igniter 1
R12/5. Passenger airbag igniter 2
R12/6. Rear left seat belt pretensioner igniter
R12/7. Rear right seat belt pretensioner igniter
R12/11. Rear left side airbag igniter (with Sidebag rear left and right option)
R12/12. Rear right side airbag igniter (with Sidebag rear left and right option)
R12/13. Driver airbag igniter 1
R12/14. Driver airbag igniter 2
R12/20. Front left side airbag igniter
R12/21. Front right side airbag igniter
R12/22. Rear left window airbag igniter (with Windowbag option)
R12/23. Rear right window airbag igniter (with Windowbag option)
S6. Hazard warning light switch
S68/1. Seat belt buckle switch and seat belt warning, driver
S68/2. Seat belt buckle switch and seat belt warning, passenger
S68/11. Rear left seat belt buckle switch
S68/12. Rear right seat belt buckle switch
S68/14. Centre rear seat belt buckle switch
S100. Seat occupancy detection switch, front passenger seat (with Maxi-Vario package option).