GF82.85-P-0003-07FQ Cockpit Management and Data System (COMAND) Switch on/Off Behavior

GF82.85-P-0003-07FQ Cockpit Management and Data System (COMAND) Switch on/Off Behavior
MODEL 218
- with CODE (512) COMAND APS with DVD changer
- with CODE (526) COMAND with single DVD drive (without navigation)
- with CODE (528) COMAND with DVD changer
MODEL 218
- with CODE (527) COMAND APS with single DVD drive (with navigation system)
- except CODE (498) Japan version

Cockpit Management and Data System (COMAND), switching on/ off characteristic, general
Switching on the COMAND controller unit (A40/3) activates not only the COMAND controller unit but also the audio/COMAND display (A40/8).
The COMAND controller unit sends a switch-on request via telematics CAN (CAN A) to the audio/COMAND display, which acknowledges the switch-on by issuing a warning message with general information on using the Cockpit Management and Data System.
A "Wake-Up" signal is also sent over a direct line to all Media Oriented System Transport (MOST) subscribers, which activates the corresponding control units.
The switch on/off characteristic comprises the following subfunctions:
^ Automatic by switching circuit 15R on/off
^ Manually by pressing the "ON" button on the COMAND controller unit
^ Switch-off characteristics by deactivating circuit 15C
^ Automatic switch-off in the event of undervoltage
^ Switch off behavior (run-on mode) when the destination has not been reached

Automatic by switching circuit 15R on/off
Activation of circuit 15R in the electronic ignition lock control unit (N73) switches on the COMAND controller unit, insofar as it was switched on when the transmitter key (A8/1) was last removed. The last active audio application is started and the corresponding basic menu shown on the audio/COMAND display.

Manually by pressing the "ON" button on the COMAND controller unit
Pressing the "ON" button enables the COMAND controller unit and the Audio/COMAND display to also be switched on and off even when the transmitter key has been removed.
If it was switched on, all audio system functions are available for t = 30 min. After this, the COMAND controller unit and the Audio/ COMAND display are automatically switched off.

Switch-off characteristics by deactivating circuit 15C
The COMAND controller unit and the Audio/COMAND display are switched off when the transmitter key is removed (circuit 15C OFF).
The run-on time of t = 30 min. (standby) of the navigation system starts. During the run-on time, all the important localizing parameters remain stored.
The run-on time of the COMAND system can be set; this is done during the installation of the COMAND controller unit in the factory.
A switched off COMAND controller unit is always in standby mode when the interior CAN (CAN B) is active.

Automatic switch-off in the event of undervoltage
In the event of undervoltage of the on-board electrical system battery (G1), a corresponding warning message appears on the Audio/ COMAND display that prompts the driver to start the engine.
If the engine is not started, an additional warning message occurs after t = 3 min., indicating that the system will switch off if the engine is not started in t = 10 s.
If the system has shut off and the on-board voltage increases again, the COMAND controller unit does not switch back on automatically. The COMAND controller unit can then be manually switched on again.
The warning procedure then runs again, until the cause for the undervoltage is rectified. If the battery is in a critical condition (e.g. short circuit in the battery), the system may be switched off without any warning message being issued.

Switch off behavior (run-on mode) when the destination has not been reached
If the active route guidance, for example, is interrupted while refueling, the navigation function remains active for up to max. t = 2 h and is automatically continued when the vehicle is started again.
After t = 2 h elapse, the route guidance has to be selected again and activated in the navigation menu.