Overall network (GVN) function

N10/1

N10/2

N18

N22

N26/9

N2/7

N32/1

N32/2

N22/7

CAN-B

N28/1

N62

N69/1

N69/2

N69/3

N69/4

N70

N72/1

A6n1

A1

N72

N73

N80

CAN-C

D2B

A2

A40/3

N3/9

N3/10

N15/3

N15/5

N15/6

N47-5

Networking of Controller Area Network (data bus/CAN bus) (CAN)

A1 Instrument cluster

A2 Radio (with code (756) MB Audio 10 CD radio with VK/RDS, with code (753) MB Audio 10 CC radio with VK/RDS, with code (353) Audio 30 APS)

A40/3 COMAND operating, display and controller unit
(with code (352) COMAND operating and display system)

A6n1 STH control unit
(with code (228) Stationary heater)

N2/7 Restraint systems control unit

N3/9 CDI control unit
(with diesel engine)

N18 HEAT [HAU] control and operating unit
(without code (580) Air conditioning or with Tempmatic for USA, without code (580) Automatic air conditioning, without code (581) Automatic air conditioning, without code (581) Comfort automatic air conditioning)

N22 AAC [KLA] control and operating unit
(with code (580) Air conditioning or with Tempmatic for USA,
with code (580) Automatic air conditioning)

N22/7 Comfort AAC control and operating unit (with code (581) Automatic air conditioning,
with code (581) Comfort automatic air conditioning)

N3/10 ME-SFI [ME] control unit
(with gasoline engine)

N10/1 Front SAM control unit with fuse and relay module

N10/2 Rear SAM control unit with fuse and relay module

N15/3 ETC control unit
(with transmission 722)

N15/5 Electronic selector lever module control unit
(with transmission 722)

N15/6 Automated manual transmission control unit (with code (424) Sequentronic automated manual transmission (SEQ))

N26/9 Special vehicle multifunction control unit (SVMCU)
(with code (450) Taxi version,
with code (934) Taxi emergency alarm system, with code (930) Taxi emergency call, with government vehicles, with panic alarm)

N28/1 Trailer recognition control unit (with code (550) trailer hitch)

N32/1 Driver-side front seat adjustment control module with memory (with code (275) driver seat, steering column and electrically adjustable outside mirror with memory)

N70 Overhead control panel control unit

N72 Lower control panel control unit
(with code (219) Distronic (DTR),
with code (228) Stationary heater,
with code (450) Taxi version)

N72/1 Upper control panel control unit

N73 EIS [EZS] control unit

N80 Steering column module

CAN-B Controller area network bus class B (interior compartment) (CAN B)

CAN-C Controller Area Network bus, class C (engine compartment) (CAN C)

D2B Digital data bus (D2B)

N32/2 Passenger-side front seat adjustment control unit with memory (with code (242) Electrically adjustable front passenger seat with memory)

N47-5 ESP and BAS control unit
(with code (472) Electronic Stability Program (ESP))

N62 PTS control unit
(with code (220) Parktronic system (PTS))

N69/1 Door control module front left

N69/2 Door control module front right

N69/3 Left rear door control unit
(model 203.0/2)

N69/4 Right rear door control unit
(model 203.0/2)

Digital data bus networking (D2B)

A2 Radio (with code (756) MB Audio 10 CD radio with VK/RDS, with code (753) MB Audio 10 CC radio with VK/RDS, with code (353) Audio 30 APS)

A2/6 CD player with changer (in glove compartment) (with code (819) CD changer or 6-disk CD changer)

A2/13 Sound amplifier
(with code (810) Sound system)

A34/4 Telephone interface
(with code (854) MB cell phone)

A35/11 Voice control system control unit
(with code (813) Voice control system (VCS [SBS]))

D2B

A2

A35/11

A35/13

CAN-B

A34/4

A40/3

N123/1

A2/13

A2/6

A35/17

A35/17

A35/13 Telephone transmitter/receiver, D2B
(with code (853) MB standard telephone, with code (855) TELE AID, with code (930) Taxi emergency call)

A35/17 Telephone transmitter/receiver and TELE AID, D2B
(with code (855) TELE AID, with code (930) Taxi emergency call)

A40/3 COMAND operating, display and controller unit
(with code (352) COMAND operating and display system)

N123/1 UPCI [UHI] control unit (Universal Portable Cell Phone Interface)
(with code (388) Telephone "Cell Phone", UPCI [UHI] system)

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CAN-B Controller area network bus class B (interior compartment) (CAN B)

D2B Digital data bus (D2B)

 The following control units can be integrated in the D2B, depending on the country and the equipment:

 E-call control unit (only , )

 SDAR control unit (only  with code (352) COMAND operating and display system)

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Function

Most control units are linked to each other via data bus lines. Control commands or messages are coded and placed on the data bus on a message-orientated or address-orientated basis, the individual control units having different priorities i.e. different access rights.

The coded commands or messages can now only be received by control units for which access is authorized.

The corresponding actuators are then actuated by these control units. In certain cases, various received messages are also combined in a control unit to form a new message. The new message is then also available for other control units on the data bus system.

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Basically, the following data bus systems are involved in the networking:

 Controller area network bus class B (interior compartment) (CAN B)

 Controller Area Network bus, class C (engine compartment) (CAN C)

 Digital data bus (D2B)

Distinguishing features

 The CAN-B is responsible for data transfers in the vehicle interior. It interconnects the different systems that can be operated by the driver or the front passenger (e.g. power windows, interior air conditioning). The CAN-B operates at a transfer rate of 83.3 kbits/s.

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 The CAN-C is responsible for data transfers in the engine compartment for the propulsion and chassis systems. The CAN-C operates at a transfer rate of 500 kbits/s.

 The D2B is an optical data bus system. Here, data is transferred via fiber optic cable to the connected information, navigation and communication components. The D2B operates with a transfer rate of 5.6 Mbits/s.

 Greater demands are made of the CAN C with regard to interference immunity, e.g. to the electromagnetic effect or radiation, and the data transfer rate.

Data transfer between the bus systems

The following control units form the interface between the bus systems:

 The electronic ignition switch control unit (N73) connects CAN-B and CAN-C.

 The COMAND operating, display and controller unit (A40/3) or the radio (A2) connects the CAN B and the D2B.

The EIS [EZS] control unit (N73) also forms the interface between the control units on the CAN B and the line to the data link connector for STAR DIAGNOSIS.

As of 1.7.02 a steering column module (N80) is fitted which is connected with CAN-B and CAN-C. However this is not used as an interface (Gateway). All the button operations on the multifunction steering wheel (MFL) as well as switch operations are read in by the steering column module (N80) and placed on CAN-B. The driving direction movements are detected by the steering angle sensor and placed on CAN C via the steering column tube module (N80). These signals are then available to the Electronic Stability Program (ESP) with code (472) Electronic Stability Program (ESP) and the Distronic (DTR) with code (219) Distronic (DTR).

Although the instrument cluster (A1) is connected both to the CAN-B and CAN-C and exchanges data with both bus systems, it does not serve as an interface (gateway).