X Series E83 X3 2.5i (M54) OFFRD
The passenger seat-occupancy detector is based on an evaluation of the surface pressure generated by the
person sitting down. The electronic evaluation decides whether a person or a child seat is occupying the seat. If
a one-year-old child in a child seat is detected, the airbags on the passenger side are deactivated (warning lamp
for passenger-airbag deactivation lights up).
[more ...]
Several control units make up the multiple restraint system (MRS):
-
Multiple restraint system control unit
All gas generators and sensors in the multiple restraint system (MRS) are connected to the MRS control unit.
The MRS control unit evaluates the data it receives from the sensors. In the event of a head-on or side impact,
the control unit determines whether it is necessary to deploy any airbags and which airbags should be deployed.
[more ...]
-
Digital motor electronics or digital diesel electronics
When an airbag is triggered, the electric fuel pump is switched off by the DME or DDE (DME = Digital Motor
Electronics, DDE = Digital Diesel Electronics).
Signal path: MRS control unit -> K bus -> instrument cluster -> PT-CAN -> DME or DDE -> direct line -> fuel-
pump relay> electric fuel pump
-
Instrument cluster
The instrument cluster triggers the optical and audible seat-belt warning.
The MRS control unit only sends a message on the status of the seat belts and the seat-occupancy detector.
The instrument cluster receives the status message from the MRS control unit via the body bus when terminal R
is ON. Depending on the status, the optical and audible warning is triggered when terminal 15 is ON.
The following components are controlled:
-
Ignition circuit for the airbags
With the maximum amount of equipment, the multiple restraint system consists of the following ignition circuits:
•
Driver's airbag (stage 1)
•
Passenger airbag (stage 1)
•
Driver's airbag (stage 2)
•
Passenger airbag (stage 2)
•
Side airbag in the front left door
•
Side airbag in the front right door
•
Side airbag in the left rear door (option 261)
•
Side airbag in the right rear door (option 261)
•
Left-hand head airbag
•
Right-hand head airbag
•
Belt tensioner, front left
•
Belt tensioner, front right
•
Safety battery terminal
Driver and passenger airbag
The driver and passenger airbag reduce the risk of injury to the occupants in the event of a head-on
collision.
The driver airbag is located in the centre pad on the steering wheel. The passenger airbag is integrated into
the instrument panel above the glove compartment. The driver and passenger airbags each have a dual-
SBT Multiple restraint system 4 E83
BMW AG - TIS
10.02.2013 16:32
Issue status (12/2007) Valid only until next DVD is issued
Copyright
Page - 3 -
