Shown on model 213.0 |
A26/17 | Head unit |
P82.89-2070-06
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 controller unit for entertainment and communication systems integrated into vehicle
Evaluating and forwarding control signals
Reading in of input signals as well as actuation of output media and system components
Central controller unit for entertainment and communication systems integrated into vehicle
The head unit generates a structured user interface for operating the various components of the entertainment and communication system:
Audio system (e.g. radio and other multimedia devices)
Telephony (with address 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))
Emergency call (with code 351 (Emergency call system (HERMES)))
The user interface is shown on the Audio/COMAND display (A40/8).
Model 213
with code 357 (Map navigation)
with code 522 (Audio 20 radio)
except code 506 (Audio 20 NTG 5.5 radio)
except code 520 (Audio 20 USB)
except code 531 (COMAND APS)
The functions of the navigation mode can be called up using 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 operation signals of the left lower control panel (N72/4) and the right lower control panel (N72/5) over the telematics CAN (CAN A), evaluates them and transmits function-specific CAN messages to the user interface CAN (CAN HMI). If the "Individual" transmission mode is selected using the DYNAMIC SELECT switch (N72/4s1), the head unit also shows additional selection options 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
Ethernet
CAN
The head unit is a telematics CAN and user interface CAN subscriber:
The following signals are among those received by the head unit via the telematics CAN:
Operation signals from the Audio/COMAND control panel (A40/9) (except code 446 (Touchpad only)) or from the touchpad (A105) (with code 448 (Touchpad) or code 446 (Touchpad only))
Control signals from the upper control panel control unit, from the left lower control panel and from the right lower control panel over the Audio/COMAND control panel
The following signals are among those transmitted by the head unit via the telematics CAN:
Control signals to the audio/COMAND display
Control signals for displays in the upper control panel control unit to the Audio/COMAND control panel
Via the user interface CAN, the head unit receives e.g from the instrument cluster (A1) the signals of the instrument cluster multifunction steering wheel button group (S163/1) and the head unit multifunction steering wheel button group (S163/2), and from the electronic ignition lock control unit (N73) it receives 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 as well as from the left lower control panel and from the right lower control panel 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 30t
Circuit 31
FM 1, AM, CL [ZV], DAB and KEYLESS-GO antenna amplifier (A2/18) (input)
FM 2 and DAB Band III antenna amplifier (A2/108) (model 213.0) or FM 2, DAB and TV 2 antenna amplifier (A2/19) (model 213.2) (input)
Driver hands-free system microphone (B25/20) and front passenger hands-free system microphone (B25/21) (input)
GPS antenna (A2/23), on vehicles with code 355 (Preinstallation for navigation retrofit) (input)
Audio muting from HERMES control unit (N112/9) (with code 362 (HERMES LTE) or with code 360 (HERMES UMTS)) (input)
Universal Serial Bus (USB) line to HERMES control unit (with code 367 (Live Traffic Information)) (input and output)
High Speed Video Link (HSVL) line from the parking system control unit (N62) (with code 235 (Parking Pilot with PARKTRONIC), with code P44 (Parking Package)) or from the reversing camera control unit (N66/2) (with code 218 (Reversing camera) and except code 235 (Parking Pilot with PARKTRONIC) and except code P44 (Parking Package)) (input)
Bluetooth® antenna (A2/91) (input and output)
Multimedia connection unit (A90/5) (input and output)
HSVL line for video data to Audio/COMAND display (output)
Wake-up for MOST (output)
Audio output (speaker) (except CODE 810 (Sound system)) (output)
Switch-on signal and power supply for the mobile phone contact plate (X237/1) (with code 379 (Telephone module with Bluetooth® (SAP))) or the cellular telephone system antenna amplifier/compensator (A28/15) (with code 379 (Telephone module with Bluetooth® (SAP)) up to 31.05.2016) (output)
Microphone output to HERMES control unit (with code 362 (HERMES LTE) or code 360 (HERMES UMTS)) (output)
Ethernet
Via Ethernet, the head unit receives software uploads for all MOST subscribers from the diagnostic connector (X11/4) connected to the diagnostic unit.
Structure
The following components are integrated in the head unit:
Arithmetic unit
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 navigation system (GPS) receiver
Gyro sensor (2D)
Traffic data recorder for TMC, TMCpro
Head unit electrical fuse (A26/17f1) in the combination connector at the rear panel