FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Mercedes Benz >> 2002 >> C 230 Kompressor (203.747) L4-2.3L SC (111.981) >> Repair and Diagnosis >> Accessories and Optional Equipment >> Accessory Control Display >> Description and Operation >> GF82.85-P-3136FAC COMAND Controller Unit, Component Description

GF82.85-P-3136FAC COMAND Controller Unit, Component Description



GF82.85-P-3136FAC COMAND Controller Unit, Component Description

MODEL 203.7
- with CODE (527) COMAND APS with single DVD drive (with navigation)
MODEL 203.7 as of model year 09/YoM 08 model refinement package







A40/3 COMAND operating, display and controller unit

Location
The COMAND operating, display and controller unit is installed in the center console.

Task
The COMAND operating, display and controller unit is used to control the following systems:
- Audio:
- Radio operation with integrated radio tuner
- Audio CD operation with integrated DVD drive
- Integrated basic audio amplifier
- Amplifier for sound system (N40/3), with code (810) Sound system
- CD player with changer (in glove compartment) (A2/6) code (819) 6-disk CD changer
- AUX jack in glove compartment

- Navigation: with integrated GPS receiver, turn rate sensor, navigation processor and DVD drive
- Telephone, with code (386) Mobile phone
- UPCI [UHI] (Universal Portable Cell Phone Interface) control unit (N123/1)
- Voice control, with code (813) Voice control system (VCS [SBS]):
- Voice control system control unit (A35/11)
- Interface between Media Oriented System Transport (MOST) and interior CAN
- Diagnosis gateway for all MOST components

The COMAND operating, display and controller unit reads in the following signals via direct lines:
- Circuit 30
- Circuit 31
- Wake-up
- AUX input
- GPS antenna (A2/49a2)
- Amplifier module 2, window antenna (A2/72)

The COMAND operating, display and controller unit processes signals and transmits the following output signals via direct lines:
- Signals for speakers, except code (810) Sound system
- Switching voltage for antennas

The COMAND operating, display and controller unit receives, processes signals and transmits signals via the following data bus systems:
- Interior CAN
- MOST

Design
- Operating unit
- Color display
- DVD drive
- Global Positioning System (GPS) receiver
- Turn rate sensor
- Navigation processor
- Control electronics
- Basic audio amplifier
- External additional fan

Function
A distinction is made between the following functional areas:
- Operating elements
- Graphic editing and image output
- Audio signal output
- Info menu
- Diagnostic interface and fault management
- Navigation processor and GPS receiver
- Yaw rate sensor
- DVD and DVD disk drive
- Traffic data recorder

Operating elements
The control buttons and switches on the function keypad in the COMAND operating, display and controller unit are read in by the microcontroller and transferred to the central processor. The keypad entries are processed in the central computer or via MOST or the interior CAN in the form of a data telegram.

Graphic editing and image output
The video subsystem takes over editing and output of the control displays. The operating screens are put out internally by the video subsystem via the composite video (FBAS) signal input to the display.

The information and amplitudes of the 3 basic colors red, green and blue as well as a synchronization signal are included in the composite color video signal.

The control electronics in the display unit evaluates the composite color video signal and controls the individual pixels line by line in terms of color and intensity. There is a pulse at the end of each line which synchronizes the horizontal video signal. The electronic circuitry of the display unit then starts the next line. Once the last line of the display is reached, a pulse is generated that synchronizes the vertical picture signal. The electronics then actuate the 1st line again.

Audio signal output
The audio signals from the various sources (CD, voice output for destination-oriented navigation, etc.) are prepared by the COMAND operating, display and controller unit and amplified before being output via the vehicle speakers. If the vehicle is equipped with code (810) Sound system, the final amplification of the audio signals is performed by the sound system amplifier (N40/3). For this purpose, the audio source data is transmitted digitally to the sound system amplifier.

Info menu
Using the "i" or "INF keys" takes you straight to the information menu. This usability can be selected independent of the source (e.g. from telephone or radio menu). The "Back" key is used to return to the screen from which the info was selected. If Mode point has been selected in the Info menu, then when the Back key is pressed one jumps back to the screen that preceded the Info menu.

Diagnostic interface and fault management
While the COMAND operating, display and controller unit is active, the system stores all faults in non-volatile memory. These can be read out via the data link connector (X11/4) using STAR DIAGNOSIS. It is not possible to output faults via the display. Diagnosis also includes the components connected to the MOST ring, which all have their own fault memory. The faults are transmitted upon request by STAR DIAGNOSIS via the MOST to the COMAND operating, display and controller unit, and can then be read out.

Navigation processor and GPS receiver
The navigation processor is the central component of the navigation system. It is integrated into the COMAND operating, display and controller unit, and calculates the vehicle location from the signals received and the vehicle route after the destination has been entered. The GPS receiver is a part of the navigation processor. It evaluates the satellite signals coming from the GPS antenna and uses them to calculate the vehicle position.

Gyro sensor
The turn rate sensor determines vehicle direction changes. It is installed into the navigation processor. A calibration is not required.

DVD and DVD disk drive
With the aid of the integrated multi-standard DVD drive, data can be read from a special navigation DVD, or audio CDs can be played.

The following data are contained on the navigation DVD:
- Program data for execution in navigation processor
- Voice data for voice output
- Map data

The traffic data memory
The integrated traffic data recorder receives the traffic messages either via MOST or internally from the radio tuner. The data is stored in the traffic data recorder for a maximum of 30 minutes (up to 100 messages), even during the run-on time of the COMAND operating, display and controller unit.

The traffic data memory decodes the messages and transmits them to the navigation processor as required. For synchronization, the traffic data recorder requires a current location list from the navigation processor. The monitoring points required for checking the road network (e.g. highway exit) are defined in this list by unique numbers. The location list is stored on the DVD. It is automatically loaded (e.g. if DVD is changed) from the navigation processor into the traffic data recorder.





pro multis Credits:Operation CHARM About Operation CHARM