Overall network (GVN) function - GF00.19-P-0001CW
MODEL 204.0 up to Model Year 8
General overall network
Controller Area Network (data bus/CAN bus) (CAN):
The CAN is an electrical bus system for the transmission of data on two lines.
The CAN consists of a twisted two-core data line that connects all CAN participants (control units) via a parallel connection. The two lines of the data line must not be swapped (low level/high level). Each connected control unit is able to transmit or receive data (bidirectional bus). The data is transmitted digitally on the CAN at various intervals. The individual data blocks are defined in a data protocol and it is specified which data are received or transmitted by a control unit.
The sum of the data blocks, the short break between two transmission intervals and other properties of the CAN are checked constantly. Detected faults are stored and placed in the fault memory.
The CAN offers the following advantages:
- Data exchange between individual control units
- Readying sensor signals for several systems
- Reducing the number of electrical lines
- Improving the electromagnetic compatibility (EMC)
The following CAN systems are involved in the overall network:
- Telematics CAN
- Interior CAN
- Drive train CAN
- Diagnostic CAN
- Chassis CAN
- Front end CAN
- Vehicle dynamics CAN
Media Oriented System Transport (MOST):
MOST is a networking system comprising a fiber optic cable that makes use of optical information transfer. With this system, data are transferred by light pulses. They are transmitted to the components connected to the MOST ring (e.g. audio components). The light pulses are then reconverted into electric signals in the receiver component.
Due to its high transfer rate, the MOST ring can simultaneously transmit source data (music, video, voice, etc.) and check data (commands, instructions etc.) without compromising the information content.
The MOST offers the following advantages:
- Extremely high data transfer rate
- Prevents tapping and crosstalk
- Data transmission is not sensitive to electromagnetic radiation
- Short-circuit resistance
- Potential-free connection of the MOST ring subscribers
- No oxidation
- Low weight of fiber optic cable
- Small line diameter
Moreover, various components are connected to the control units via local interconnect network (LIN). The following various
LINs are installed:
- Instrument panel LIN
- Wiper/inside rearview mirror LIN
- Rear SAM LIN
- Left door LIN
- Right door LIN
- On-board electrical system LIN
- Climate control LIN
- Drive train LIN
- Steering LIN
More information on these connections can be found in the corresponding function descriptions.
Data transfer between the bus systems
The following control units form the interface between the bus systems:
- The front SAM control unit connects the interior CAN, diagnostic CAN, chassis CAN, and the front end CAN
- The radio or the COMAND controller unit connects the telematics CAN, interior CAN, and the MOST
- The Electronic Stability Program control unit connects the chassis CAN to the vehicle dynamics CAN
- The CDI control unit or the ME-SFI [ME] control unit connect the drive train CAN to the chassis CAN
Telematics CAN
The telematics CAN is responsible for telecommunication data transfer. The telematics CAN operates at a transfer rate of 125 kBit/s.
The telematics CAN interconnects the following control units:
- Radio or COMAND controller unit
- Audio/COMAND display
- Audio/COMAND control panel
Interior CAN
The interior CAN is responsible for data transfer in the vehicle interior. It interconnects the different systems that can be operated by the driver or the front passenger (e.g. power windows, climate control, etc.). The interior CAN operates at a transfer rate of 125 kBit/s.
The following control units are connected to each other over the interior CAN:
- Instrument cluster
- Radio or COMAND controller unit
- Panoramic sliding roof control module
- front SAM control unit
- Rear SAM control unit
- Automatic air conditioning control and operating unit
- Special-purpose vehicle multifunction control unit
- Trailer recognition control unit
- Driver seat control unit
- Front passenger seat control unit
- PARKTRONIC control unit
- Left front door control unit
- Right front door control unit
- Left rear door control unit
- Right rear door control unit
- KEYLESS GO control unit
- Overhead control panel control unit
- Electronic ignition switch control unit
- Tire pressure monitor control unit
- Weight Sensing System (WSS) control unit
Drive train CAN
The drive train CAN is responsible for data transfer for the drive systems. The drive train CAN operates at a transfer rate of 500 kBit/s.
The following control units are connected to each other over the drive train CAN:
- CDI control unit or ME-SFI [ME] control unit
- Electronic transmission control control unit or fully integrated transmission control control unit
- Fuel pump control unit
- Electronic selector lever module control unit
Diagnostic CAN
The diagnostic CAN is responsible for the data transfer of diagnostic data and for the connection of an external diagnostic unit (e.g. STAR DIAGNOSIS) and the emergency call system control unit. The diagnostics CAN operates at a transfer rate of 500 kBit/s.
The following control units are connected to each other over the diagnostics CAN:
- front SAM control unit
- Emergency call system control unit
Chassis CAN
The chassis CAN is responsible for data transfer between the chassis systems. The chassis CAN operates at a transfer rate of 500 kBit/s.
The following control units are connected to each other over the chassis CAN:
- Instrument cluster
- Left front reversible emergency tensioning retractor
- Right front reversible emergency tensioning retractor
- CDI control unit or ME-SFI [ME] control unit
- Supplemental restraint system control unit
- front SAM control unit
- Electronic Stability Program control unit
- Electronic ignition switch control unit
- Steering column module control unit
Front end CAN
The front end CAN is responsible for the data transfer between the xenon light control units as well as to the front SAM control unit. The front end CAN operates at a transfer rate of 500 kBit/s.
The following control units are connected to each other over the front end CAN:
- front SAM control unit
- Left xenon lamp control unit
- Right xenon light control unit
Vehicle dynamics CAN
The vehicle dynamics CAN is responsible for the data transfer of driving dynamics data (e.g. rotational speed, longitudinal acceleration, etc.). The vehicle dynamics CAN operates at a transfer rate of 500 kBit/s.
The following control units are connected to each other over the vehicle dynamics CAN:
- Yaw rate, lateral and longitudinal acceleration sensor
- Electronic Stability Program control unit
MOST
MOST is an optical data bus system. Here, data is transferred via fiber optic cables to the connected information, navigation, and communication components. The MOST operates with a transfer rate of 22 Mbits/s.
The MOST interconnects the following control units:
- Radio or COMAND controller unit
- Sound system amplifier control unit
- Digital Audio Broadcasting control unit
- SDAR control unit
| Overall network (GVN) block diagram | GF00.19-P-0001-03CW | ||
| Instrument cluster, component description | A1 Without code (442) Comfort multifunction steering wheel |
GF54.30-P-6000CWA | |
| With code (442) Comfort multifunction steering wheel | GF54.30-P-6000CWB | ||
| Radio control panel component description | A2 With code (523) MB Audio 20 radio |
GF82.60-P-3116CW | |
| With code (494) USA version | GF82.60-P-3116CWA | ||
| With code (510) Audio 20 with CD changer | GF82.60-P-3116CWB | ||
| Radio/navigation unit, component description | A2/56 With code (525) MB Audio 50 APS radio |
GF82.61-P-4111CW | |
| With code (511) Audio 50 APS with DVD changer | GF82.61-P-4111CWA | ||
| COMAND controller unit, component description | A40/3 With code (527) COMAND APS with single DVD drive (with navigation system) |
GF82.85-P-3136CW | |
| With code (512) COMAND APS with DVD changer | GF82.85-P-3136CWA | ||
| With code (498) Japan version | GF82.85-P-3136CWJ | ||
| Cockpit central display, component description | A40/8 With code (494) USA version entry or with code (510) Audio 20 with CD changer entry or with code (511) Audio 50 APS with DVD changer entry or with code (523) MB Audio 20 radio entry or with code (525) MB Audio 50 APS radio entry |
GF54.30-P-6100CW | |
| With code (498) Japan version high or with code (512) COMAND APS with DVD changer high or with code (527) COMAND APS with single DVD drive (with navigation) high | GF54.30-P-6100CWH | ||
| Front central operating unit, component description | A40/9 | GF54.21-P-4500CW | |
| Front reversible emergency tensioning retractor, component description | A76, A76/1 With code (299) PRE-SAFE |
GF91.40-P-4020CW | |
| Panoramic sliding roof control module, component description | A98 With code (413) Panoramic glass sunroof with top sliding sunroof |
GF77.20-P-4106CW | |
| Yaw rate, lateral and longitudinal acceleration sensor, component description | B24/15 | GF42.45-P-4810CW | |
| Xenon light control unit, component description | E1n1, E2n1 With code (614) Bi-xenon headlamp unit or with code (622) Intelligent Light System (right-hand traffic) |
GF82.10-P-2119CW | |
| Supplemental restraint system control unit, component description | N2/10 | GF91.60-P-4068CW | |
| Component description for CDI control unit | N3/9 For engine 646.8 |
GF07.16-P-6000CW | |
| Front SAM control unit with fuse and relay module, component description | N10/1 | GF54.21-P-6070CW | |
| Rear SAM control unit with fuse and relay module, component description | N10/2 | GF54.21-P-6030CW | |
| ETC [EGS] control unit, component description | N15/3 With TRANSMISSION 722.6 |
GF27.19-P-4018CW | |
| Electronic selector lever module control unit, component description | N15/5 With transmission 722.6/9 |
GF27.60-P-5163CW | |
| Automatic air conditioning control and operating unit, component description | N22/7 Without code (581) Comfort automatic air conditioning |
GF83.40-P-3000CWA | |
| with code (581) Comfort automatic air conditioning | GF83.40-P-3000CWB | ||
| Special vehicle multifunction control unit (SVMCU [MSS]), component description | N26/9 With code (965) Electrical preinstallation for rental vehicles |
GF54.21-P-4010CW | |
| Trailer recognition control unit component description | N28/1 With code (550) Trailer hitch |
GF31.19-P-4050CW | |
| Electronic Stability Program control unit component description | N30/4 | GF42.45-P-5119CW | |
| Driver seat control unit component description | N32/1 With code (275) Memory package (driver seat, steering column, mirrors) |
GF91.29-P-5231CW | |
| Front passenger seat control unit, component description | N32/2 With code (242) Electrically adjustable front passenger seat with memory |
GF91.29-P-5241CW | |
| Audio tuner control unit, component description | N40/3 With code (810) Sound system |
GF82.62-P-3132CWS | |
| PARKTRONIC control unit component description | N62 With code (220) Parktronic system (PTS) |
GF54.65-P-5001CW | |
| Left front door control unit, component description | N69/1 | GF72.29-P-6001CW | |
| Right front door control unit, component description | N69/2 | GF72.29-P-6009CW | |
| Rear door control unit, component description | N69/3, N69/4 | GF72.29-P-6021CW | |
| Keyless Go control unit, component description | N69/5 With CODE (889) Keyless Go |
GF80.61-P-4204CW | |
| Overhead control panel control unit, component description | N70 With code (414) Power glass tilting/sliding sunroof |
GF82.20-P-5216CW | |
| Electronic ignition switch control unit, component description | N73 | GF80.57-P-6001CW | |
| Steering column module control unit, component description | N80 | GF54.21-P-6051CW | |
| Digital Audio Broadcasting control unit, component description | N87/3 With code (537) Digital radio |
GF82.62-P-5000CW | |
| Satellite radio, component description | N87/5 With code (536) SIRIUS satellite radio |
GF82.85-P-3105CWU | |
| Tire pressure monitor control unit, component description | N88 With code (470) Tire pressure monitor (standard) |
GF40.15-P-5124CW | |
| Weight Sensing System (WSS) control unit, component description | N110 With code (494) USA version |
GF91.60-P-4069CWU | |
| Emergency call system control unit, component description | N123/4 With code (359) TELE AID emergency call system |
GF82.95-P-3212CWU | |
| VGS control unit, component description | Y3/8n4 With transmission 722.9 |
GF27.19-P-4016CWQ |