Mercedes-Benz Body & Equipment Guideline for Metris - BM 447, Version November 27, 2015.
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Please observe the revision notes compared to 09/18/2015 ! Only print out complete sections of the current version!
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9.4 Interfaces/electrical lines
9 Electrical system
9.4.3 CAN bus and networking
The electronic systems available in the engine/passen-
ger compartments are connected to one another via
networks (bus systems). Gateways are used to transfer
data between the individual bus systems.
These bus systems include:
•
LIN bus (Local Interconnect Network)
•
Ethernet
•
MOST bus (Media Oriented Systems Transport)
•
CAN bus (Controller Area Network) including:
•
Body CAN
•
Head unit CAN
•
Chassis CAN
•
Diagnostic CAN
•
Upfitter CAN (
•
CIA CAN
a
WARNING
Interference with the bus systems (e.g. by discon-
necting, extending or "tapping") is not permissible.
Any modifications to the bus systems can lead to
failure of safety-relevant components and conse-
quently to accidents or damage to the vehicle.
The ring-shaped MOST network of the Metris uses a
fiber-optic cable as a data carrier for transferring audio
and control signals. This system supports the synchro-
nous transfer of data at high baud rates, is insensitive
to electromagnetic interference (EMC), does not itself
cause electromagnetic interference and can transfer
both audio and control data simultaneously. The system
is also available with the ignition off and is activated by
a separate wake-up line.
Internal and external vehicle diagnosis can be carried
out by means of the OBD diagnostic socket (SAE 1962).
Every control unit is capable of self-diagnosis and is
equipped with an internal fault memory.
Communication with the relevant control unit can be
established using the XENTRY Kit tester and the soft-
ware developed for this unit.
The parameterizable special module (PSM) (code ED5)
can be used to access individual types of data available
on the CAN bus (
i
Additional information
You can obtain further information on this topic from
www.upfitterportal.com
