600-2
E46 Electrical System
E46 cars are electrically complex. Many
vehicle systems and subsystems are
interconnected or integrated. In
addition, the requirements of second
generation On-Board Diagnostics (OBD
II) are such that there are now many
more circuits and wires in the vehicle
than ever before. The components
must exchange large volumes of data
with one another in order to perform
their various functions.
The use of dedicated data lines for
each link in the system has reached
the limits of its capabilities. On the one
hand, wiring harnesses now must be
so complex that they become
unmanageable. In addition, the finite
number of pins on conventional
connectors becomes a limiting factor in
electronic control module development.
The solution has been found in the use
of specialized, vehicle compatible serial
bus systems. The E46 bus system is
summarized in
Table a
.
Table a. E46 busses
Bus
Circuits covered
K-bus
Driver information
systems (instrument
cluster, Check Control,
on-board computer)
Central Body
Electronics (ZKE V)
General Module (GM
V)
Seat memory (SM)
Sunroof (SHD)
Rain sensor (AIC)
Telephone and sound
system
Headlight module
(LSZ)
Electrical System - General
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Summary of Contents for 1999-2005 M3
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