GF00.19-P-0001TMA Overall Network (GVN) Function

GF00.19-P-0001TMA Overall Network (GVN) Function
- MODEL 211.0 /2 as of model year 08/YoM 07

Networking of the control units at the Controller Area Network bus class B (interior) (CAN-B)

CAN-C Controller Area Network, bus Class C (engine compartment) (CAN-C)
MOST Media Oriented System Transport (MOST)
A1 Instrument cluster
A2 Radio
A2/56 Radio control panel and navigation unit
A6 Stationary heater (except USA)
A40/3 COMAND operating, display and controller unit
M40/1 Pneumatic pump for dynamic seat control
N2/7 Restraint systems control unit
N10/1 Driver-side SAM control unit with fuse and relay module
N10/2 Rear SAM control unit with fuse and relay module
N10/11 Passenger-side SAM control unit
N22 AAC [KLA] control and operating unit
N22/7 Comfort AAC control and operating unit (with code 581 Comfort automatic air conditioning)
N25/7 HS [SIH] and seat ventilation control unit
N26/9 Special vehicle multifunction control unit (SVMCU [MSS]) (with code 450 Taxi version)
N28/1 Trailer connection unit [AAG] control unit
N32/1 Driver front seat adjustment control unit with memory
N32/2 Front passenger front seat adjustment control unit with memory
N62 PTS control unit
N69/1 Door control module front left
N69/2 Door control module front right
N69/3 Door control module rear left
N69/4 Door control module rear right
N70 Overhead control panel control unit
N72 Lower control panel control unit
N72/1 Upper control panel control unit
N73 EIS [EZS] control unit N80 Steering column module
N88 TPM [RDK] control unit
N93 Central gateway control unit
N121 TLC [HDS] control unit (211.0)
N121/1 Rear-end door closing control unit (211.2)
N130 Loading floor control unit (211.2)

Networking of the control units at the CAN-C, illustrated with engine 273 and transmission 722.9

CAN-B Controller Area Network bus, class B (interior compartment) (CAN B)
CAN-C Controller Area Network, bus Class C (engine compartment) (CAN-C)
LIN Local interconnect network
MFL Multifunction steering wheel
A1 Instrument cluster
A89 DTR controller unit
N3/10 ME-SFI [ME] control unit
N15/3 ETC [EGS] control unit
N15/5 Electronic selector lever module control unit
N47-5 ESP control unit
N51 AIRmatic with ADS control unit
N71 Headlamp range adjustment control unit
N73 EIS [EZS] control unit
N80 Steering column module
N93 Central gateway control unit
N97 Rear axle level control system control unit
Y3/8 Electric controller unit (VGS)

MOST shown except code 494 USA version and except code 498 Japan version:

CAN-B Controller Area Network bus, class B (interior compartment) (CAN B)
MOST Media Oriented System Transport
W Wake-up line
A2 Radio
A2/56 Radio control panel and navigation unit
A40/3 COMAND operating, display and controller unit
A90/3 TV digital tuner
N40/3 Amplifier for sound system
N125/1 Media interface control unit

Overall network
A data bus is a data collecting line, the data of which can be used by almost all connected control units.

Function of networking
Most control units of the vehicle are linked to each other via data bus lines, in other words there is no direct electrical connection between a sensor and the executing actuator. A corresponding message (data) is generated using the sensor signal and made available to the data bus system.
The message is sent in a message-oriented or address-oriented manner and is evaluated by the respective control units; it can, however, be received by other control units and evaluated if necessary.
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.

Data bus systems
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)
- media-oriented system transport (MOST)
- Local Interconnect Network (LIN)

The operational field is differentiated as follows:
- The CAN-B links the control units of systems located in the vehicle interior (e.g. power windows, heated rear window).
- CAN-C networks the control units for the drive and chassis systems (e.g. engine, transmission control).
- The MOST links the control units of the audio and navigation systems via a fiber optic cable (if equipped e.g. the telephone, the voice control).
- The LIN bus is used where rather simple control and monitoring tasks are to be performed in the vehicle.

In respect of the interference immunity, e.g., electromagnetic effect or radiation, and the high data transfer rate, higher requirements are placed on the engine compartment CAN-C.

Controller Area Network (data bus/CAN bus) systems
The CAN bus systems are two-wire data bus systems. They differ from one another in terms of transfer rate depending on the requirement.

MOST bus
The MOST bus is an optical data bus system. Here the data are transferred via fiber optic cables to the connected control units for information, navigation, and communication systems.

LIN
The LIN bus is a single-wire data bus system. The LIN bus is used e.g. between the multifunction steering wheel and the steering column module.

Data exchange between the data bus systems
The radio, the radio control panel and navigation unit or the COMAND operating, display and controller unit forms the interface (Gateway) for data exchange the MOST and the CAN-B. The central gateway control unit is the interface for data interchange between the CAN-B and the CAN-C.
The steering column module, the instrument cluster and the EIS [EZS] control unit are connected both to the CAN-B and the CAN-C. However, they do not act as an interface (gateway) between the two data bus systems. The steering column module reads in the signals of the switch actuations on the steering column module and all the signals of the button actuations on the multifunction steering wheel (MFL) over the LIN bus and places these signals on the CAN-B. The steering angle at the steering wheel is sensed electronically via the steering angle sensor (N49). The signals of the steering angle are placed on CAN-C via the steering column module.