Switch-on/off characteristics, function

Activation of entire system

When the ignition switch is turned to approx. the 20° position,

(terminal 15C, ON) all further subsystems are activated, at position 1 (terminal 15 R, ON) the display is switched on, insofar as COMAND was active prior to the last time that the keys were withdrawn. The COMAND system is then ready for operation.

The system active before the last switch-off (e.g. radio) is switched back on and the corresponding basic menu is displayed.
If COMAND was switched off for longer than 30 min, a warning menu appears with general information on how to use the system.

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Reaction when "ON" button is pressed

The COMAND system can be switched on by pressing the "ON" button even when the remote control key is removed. All COMAND functions are then available for approx. 30 min. After expiration of the 30 min period, the COMAND system automatically switches off.

If switch-off has occurred after approx. 30 min, the system can be switched back on again by pressing the "ON" key. The 30 min cycle then starts again from the beginning.

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Switch off characteristics

The COMAND system is switched off when the ignition key is removed (c. 15C, OFF). After this the navigation system goes into an run-out time of approximately 30 minutes ("standby mode"). During this time, all important location finding parameters remain stored.

Moreover, the COMAND operating, display and control module COMAND (A40/3) is always in the "stand-by mode" when the CAN passenger compartment bus is active.

 Pressing the "Monitor" button, only changes the monitor between the day, night and off modes.

Switch-off when voltage is too low

The COMAND central processor constantly monitors the battery voltage.
Depending on the voltage value the system will act as follows:

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 Battery voltage between 11.5 and 9.5 V (battery warning range)
If the battery voltage drops below 11.5 V, a message appears on the display requesting that the engine be started.

If the engine is not started, another warning is output after approx. 3 min that approx. 10 s remain to start the engine before the system switches off.
In this case, starting the engine prevents the system from switching off automatically.
If the system has been run down and the voltage reading rises once again above 11.5 V, COMAND remains as it was namely off.
If a system has been shut down it can still be switched back on again manually. This warning procedure is accomplished again as long as the malfunction has not been eliminated.

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 Battery voltage less than 9.5 V (low voltage)
The COMAND system is automatically switched to a defined wait state in which only the battery voltage continues to be monitored. In addition to this the current operating status is stored. In this state, COMAND cannot be operated or activated with the STAR diagnosis tool. No further communication is accomplished with external components.