Cockpit Management and Data System (COMAND) Switch on/off behavior - GF82.85-P-0003-07GA

Switch on/off characteristics, general 

The switch on/off characteristics of the Cockpit Management and Data System (COMAND) comprise the following subfunctions:

• Activating the overall system 
• Response upon pressing the "ON/OFF" button 
• Switch-off characteristics when removing the transmitter key (A8/1) 
• Switch-off characteristics in the event of undervoltage 
• Switch off behavior (run-on mode) when the destination has not been reached 

Activating the overall system 

When the vehicle is opened, all data bus systems are activated to ensure a faster switch-on procedure. After inserting the transmitter key in the EZS control unit (N73) and turning to position 1 (circuit 15R ON), the display of the COMAND operating, display and controller (A40/3) is switched on, provided that it was switched on before the transmitter key was last removed.

The system which was active before it was last switched off (e.g. radio) is switched on and the corresponding basic menu is displayed. If the COMAND operating, display and controller unit was switched off, a warning note with general information about how to use the system generally appears when it is switched back on.

Response upon pressing the "ON/OFF" button 

The COMAND operating, display and controller unit and the display can also be switched on when the transmitter key is removed (circuit 15C OFF) by pressing the ON/OFF button. All functions are then available for t = 30 minutes After this the COMAND operating, display and controller unit switches off automatically.

Switch-off characteristics when removing the transmitter key 

The COMAND operating, display and controller unit is switched off when the transmitter key is removed (circuit 15C OFF). The run-on time of t = 30 min (standby mode) of the navigation system starts. During the run-on time, all the important localizing parameters remain stored. The run-on time of the audio system can be set; this is done during the installation of the COMAND operating, display and controller unit in the plant. The COMAND operating, display and controller unit which is not switched on is always in standby mode when the interior CAN (CAN B) is active.

Switch-off characteristics in the event of undervoltage 

In the case of battery (G1) undervoltage, a message appears on the display of the COMAND operating, display and controller unit requesting the driver to start the engine. If the engine is not started, another warning is issued after t = 3 min stating that t = 10 s remain for switching on the engine before the audio system shuts down.

If the audio system has shut off and the on-board voltage increases again, the COMAND operating, display and controller unit does not automatically switch itself on again. However, the audio system can be switched on again manually. The warning procedure then runs again, until the cause for the undervoltage is rectified.

Switch off behavior (run-on mode) when the destination has not been reached 

If the route guidance destination has not been reached, the navigation system in the COMAND operating, display and controller unit acts as follows when the engine is shut off:

• Navigation remains active up to t = 30 min. (e.g. refueling stop). Navigation continues from where it left off after restarting the vehicle.
• After t = 30 min up to a maximum of t = 2 h, the COMAND operating, display and controller unit remains in "Sleep mode". The route is recalculated after restarting the vehicle and the navigation is continued.
• After t = 2h a prompt is displayed after starting the vehicle asking whether the route should be recalculated:
  • "YES" = Route is recalculated.
  • "NO" = Navigation will cease.