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

Switch-on characteristics 

Navigation system activation 

The navigation system is activated automatically via the class B (interior) controller area network bus (CAN-B) when the driver door is opened. This process lasts for approximately 2 seconds and may be accompanied by faintly audible noises from the DVD drive integrated in the navigation processor (N41/1). The display of the COMAND operating, display and controller unit (A40/3) remains switched off.

If, as a result of this, no status change occurs at the EIS [EZS] control unit (N73), e.g. "Circuit 15C or circuit 15R ON", the navigation processor remains activated for t = 30 min. It then switches off automatically.

Activating the overall system 

Position 1 

Inserting the transmitter key (A8/1) into the EIS [EZS] control unit. With position "Circuit 15C ON", only the data bus systems are activated for t = 3 min to ensure a quicker switch-on process. If the COMAND operating, display and controller unit is switched on using the ON button (ON/OFF), automatic shutoff occurs after t = 30 min.

Position 2 

The unit is switched on by turning the transmitter key into position 1 "Circuit 15R ON" provided it was switched on before the last time the transmitter key was removed.

The function options are restricted to:

• Operation of the COMAND operating, display and controller unit
• Multifunction display (A1p13) in the instrument cluster (A1)
• Operation via multifunction steering wheel

Position 3 

All the functions in the vehicle become operational by continuing to turn the transmitter key to position 2 "Circuit 15 ON". 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 for longer than t = 30 min, a warning menu with general information on the use of the system appears.

Position 4 

The engine is started by turning the transmitter key to position 3 "Circuit 50 ON". If a considerable voltage drop occurs while starting the engine, the system switches off for this duration but switches back on again once the on-board electrical system has stabilized.

Characteristics when operating the ON/OFF button 

The COMAND operating, display and controller unit can also be switched on by pressing the ON button (ON/OFF) when the transmitter key is removed. All media-oriented system transport (most) functions are available for t = 30 min. The system switches off automatically once this time has elapsed. If the system has switched off after 30 minutes, the system can be switched on again by pressing the ON button. The cycle (30 minutes) then starts from the beginning.

On/Off characteristics via AUTO-ON 

The COMAND operating, display and controller unit changes to the function status AUTO-ON, when it is "woken up" by a MOST participant (e.g. telephone call or SMS). In this case the function status that the system was in prior to the wake-up is stored. When the functions or user instructions that were initiated by the wake-up have completed, the system status prior to the arrival of the wake-up signal is reinstated.

In AUTO-ON function mode, the COMAND operating, display and controller unit neither accepts display requests from other MOST participants nor does it wake them up. Switch-off is accomplished either via the ON button (ON/OFF) or by removing the transmitter key.

An active phone call is not interrupted by removing the transmitter key. In this case, the MOST will switch itself off later on.

Switch-off characteristics 

The COMAND operating, display and controller unit is switched off by pressing the ON button or by removing the transmitter key "Circuit 15C OFF" from the EIS [EZS] control unit.

When the MOST is shut down, the navigation system run-on time (standby mode) of t = 30 min starts. During this period all the important locating parameters are stored. Moreover, the COMAND operating, display and controller unit and the audio gateway control unit (N93/1) are always in standby mode when CAN-B is active.

Switch off characteristics at undervoltage 

The central computer of the COMAND operating, display and controller unit constantly monitors the battery voltage. Depending on the voltage value the system performs as follows.

Battery voltage is 9.5 to 11.5 V (battery warning range) 

• If the battery voltage drops below 11.5 V, a message appears in the display and requests that the engine be started.
• If the engine is not started, then a further warning follows after 3 minutes that approx. 10 seconds remain for starting the engine before the device switches off. In this case, starting the engine serves to prevent the system shutting down automatically. However, if the system has switched off and the voltage rises again above 11.5 V, the COMAND operating, display and controller unit does not switch on again.
• If a system has been shut down it can still be switched back on again manually. The warning procedure then ensues each time for as long as the fault is not eliminated.

Battery voltage below 9.5 V (undervoltage) 

The COMAND operating, display and controller unit is automatically put into a defined standby condition in which only the battery voltage is monitored. Additionally, the current operating condition is backed up. In this condition the system cannot be operated or made to respond via STAR DIAGNOSIS. All communication with external components is stopped.

Switching on/off characteristics with code (889) Keyless Go 

If the vehicle is started or stopped by pressing the Keyless Go switch (A12/1s3), this is identical to the switch-on/switch-off characteristics when starting up again with the transmitter key "Circuit 15 ON/OFF".