3 Series E92 328xi (N52K) COUPE
The signals are transferred as follows:
•
Airbag unit (signals to steering wheel)
Signal path:
MRS control unit -> SZL (signal simply looped through) -> Coil spring -> Airbag unit
•
Horn (signal from steering wheel)
Signal path:
Horn switch -> SZL (signal simply looped through) -> Junction box
•
Multifunction buttons (signal from steering wheel)
Signal path:
Multifunction buttons -> SZL -> F-CAN -> Junction box electronics (signal simply looped through) -> F-CAN
-> DSC control unit (serves as gateway) ->
PT-CAN -> Junction box electronics (serves as gateway) -> K-CAN -> Audio system
(check switch positions with BMW diagnostic system using DSC)
The control units involved in the functions of the steering column switch cluster are as follows:
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DSC: Dynamic Stability Control
The steering column switch cluster (SZL) does not have its own fault memory. All fault data for the steering
column switch cluster are stored in the DSC control unit.
The DSC is connected to the steering column switch cluster via the F-CAN (chassis CAN).
-
JBE: Junction box electronics
The junction box electronics unit is the data interface (= gateway) between the K-CAN and the PT-CAN. (K-
CAN = Body CAN; PT-CAN = Powertrain CAN).
Signals from the F-CAN (Chassis CAN) are simply looped through. This means: Signals from the F-CAN are not
received or evaluated by the junction box electronics. The F-CAN cables are simply routed through the junction
box housing.
The junction box consists of the junction box electronics and the electrical distribution centre.
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FRM: Footwell module
The footwell module controls the vehicle lighting. The footwell module is connected to the steering column
switch cluster (SZL) by direct wires.
-
CAS: Car Access System
The Care Access System reactivates the control units on the PT-CAN via the wake-up wire (terminal 15 wake-
up).
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KOMBI: Instrument cluster
Information on the on-board computer functions can be called up via the on-board computer button (BC button)
and the rocker switch. (The BC button and the rocker switch are integrated into the turn-signal/main-beam
switch).
The contents are displayed in the LCD display in the instrument cluster.
The signals for the on-board computer functions are transmitted by a direct wire from the SZL to the instrument
cluster.
System functions
The steering column switch cluster (SZL) comprises the following functions:
-
Monitoring of steering angle and steering-wheel turns
SBT Steering Column Switch E70, E71, E81, E82, E87, E90, E91, E92, E93
BMW AG - TIS
06.02.2013 06:24
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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