Head unit, component description - GF82.85-P-3140RFA
Model 205 with code 522 (Audio 20 radio) except code 520 (Audio 20 USB) except code 531 (COMAND APS)
Model 253 with code 522 (Audio 20 radio) except code 520 (Audio 20 USB) except code 531 (COMAND APS)
Shown on MODEL 205.0
Location
The head unit is centrally located in the instrument panel behind the panel at the level of the upper control panel control unit (N72/1).
Tasks
- Central operating and display unit for the entertainment and communications systems integrated in the vehicle
- Evaluating and forwarding control signals
- Reading in of input signals as well as actuation of output media and system components
Central operating and display unit for the entertainment and communications systems integrated in the vehicle
The head unit provides the user with a structured and uniform user interface for the following system components:
- Audio system (e.g. "Radio", "CD" (as well as MP3) and further multimedia devices)
- Telephony (with telephone book function)
- Internet
- - sound settings (e.g. "bass", "treble", "fader", "balance")
- System settings (e.g. "Brightness" and "Contrast" of the Audio/COMAND display)
- Navigation (with code 357 (Map navigation))
The user interface is shown on the Audio/COMAND display.
Model 205
with code 357 (Map navigation)
with code 522 (Audio 20 radio)
except code 520 (Audio 20 USB)
except code 531 (COMAND APS)
Model 253
with code 357 (Map navigation)
with code 522 (Audio 20 radio)
except code 520 (Audio 20 USB)
except code 531 (COMAND APS)
The functions of the navigation mode can be used via the voice control system.
Using the "Vehicle functions" menu, equipment-dependent contents and functions of additional systems (e.g. climate control, seat adjustments) can be shown and controlled on the Audio/COMAND display.
Evaluating and forwarding control signals
The head unit receives the control signals from the following components via the telematics CAN (CAN A):
- Left lower control panel (N72/4)
- Right lower control panel (N72/5)
- Upper control panel control unit
- Off-road operating panel (S70) (model 253.9 with code 430 (Off-road package))
The head unit evaluates the data and sends function-specific CAN messages to the user interface CAN (CAN HMI). When actuating the DYNAMIC SELECT switch (N72/4s11) (as of 01.06.2015), the AGILITY SELECT switch (N72/4s1) (up to 31.05.2015), or on vehicles of model 253.9, with code 430 (Off-road package), the on/off-road menu button (S70s1), the head unit also shows selectable transmission modes on the Audio/COMAND display.
Reading in of input signals as well as actuation of output media and system components
The head unit transmits and receives signals via the following connections:
- CAN
- Media Oriented System Transport (MOST)
- Direct line
CAN
The head unit is a telematics CAN and user interface CAN subscriber:
- Via the telematics CAN, the head unit receives e.g. the control signals from the Audio/COMAND control panel (A40/9) and from the touchpad (A105) (with code 448 (Touchpad), with code 494 (USA version) or with code 498 (Japan version)). The signals from the upper control panel control unit, the left lower control panel, the right lower control panel and the off-road operating panel (model 253.9 with code 430 (Off-road package)) are also forwarded via the Audio/COMAND control panel and telematics CAN to the head unit.
- The head unit uses the telematics CAN to send e.g. control signals to the Audio/COMAND display or control signals for the displays in the upper control panel control unit to the Audio/COMAND control panel.
- The head unit uses the user interface CAN to receive e.g. from the instrument cluster (A1) the signals from the left multifunction steering wheel button group (S110) and the right multifunction steering wheel button group (S111), and from the electronic ignition lock control unit (N73), the control signals for the displays in the upper control panel control unit.
- Via the user interface CAN, the head unit sends e.g. navigation displays to the instrument cluster or the interpreted signals from the upper control panel control unit and from the left lower control panel and from the right lower control panel and from the off-road operating panel (model 253.9 with code 430 (Off-road package)) to the electronic ignition lock control unit.
Media Oriented System Transport (MOST)
The head unit exchanges data with the following control units via MOST:
- Sound system amplifier control unit (N40/3) (with CODE 810 (Sound system))
- Tuner unit (A90/4) (with CODE 536 (SIRIUS satellite radio) or with CODE 537 (Digital radio (DAB)))
Direct line
The head unit is equipped with the following direct connections:
- Circuit 30 g
- Circuit 31
- FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier (A2/18) (input)
- FM 2 and DAB band III antenna amplifier (A2/108) (model 205.0/1, model 253) or FM 2, DAB and TV 1 antenna amplifier (A2/131) (model 205.2, model 253) (input)
- Hands-free system microphone (A67b1) (input)
- GPS antenna (A2/23), in vehicles with CODE 348 (Emergency call/assist system) via the global positioning system antenna splitter (A2/5) (input)
- Audio muting from the emergency call system control unit (N123/4) (with CODE 348 (Emergency call/assist system)) (input)
- Audio muting from the telematics services communications module (N112/1) (with code 350 (E-Call Europe emergency call system) or with code 06U (Mercedes connect me basic services) and except code 810 (Sound system)) (input)
- Reversing camera (B84/3) (with CODE 218 (Reversing camera)) (input)
- Bluetooth® antenna (A2/91) (input and output)
- Multimedia connection unit (A90/5) (input and output)
- Low Voltage Differential Signal (LVDS) line for video data to the Audio/COMAND display (output)
- Wake-up line for MOST (output)
- Audio output (speaker) (except CODE 810 (Sound system)) (output)
- Switch-on signal and power supply for mobile phone contact plate (X237/1) (with CODE 386 (Comfort telephony)) and cellular telephone system antenna amplifier/compensator (A28/15) (with CODE 386 (Comfort telephony)) (output)
- Microphone output to emergency call system control unit (with CODE 348 (Emergency call/Assist system)) to telematics services communications module (with CODE 350 (Ecall Europe emergency call system) or with CODE 06U (Mercedes connect me basic services)) (output)
- Audio output to engine sound control unit (N40/1) (with engine 276) (output)
Body
The following components are integrated in the head unit:
- Arithmetic unit
- Single drive for CDs
- Searchable database for audio files, including cover art and cover flow
- Bluetooth® receiver
- 3 radio tuners for AM reception, FM phase diversity and separate FM tuner function for data services, e.g. traffic messages
- High definition (HD) radio tuner (with CODE 494 (USA version) or CODE 460 (Canada version))
- 4-channel audio amplifier (except CODE 810 (Sound system))
- Global positioning system (GPS) receiver
- Gyro sensor (2D)
- Traffic data recorder for TMC, TMCpro or Real Time Traffic Data (RTTD)
- Head unit electrical fuse (A26/17f1) in the combination connector at the rear panel
| Cockpit Management and Data System (COMAND) control unit wiring diagram | PE82.85-P-2101-97FBA |