Data transfer between COMAND and instrument cluster, function - GF82.85-P-3008R

MODELS 203.0 /2 /7 up to 23.4.04 with CODE (352a) COMAND operating and display system with CODE (491) U.S. version 

Fig 1: Data Transfer Between COMAND And Instrument Cluster Function Diagram - Models 203.0 /2 /7 Up To 23.4.04 With Code (352A) And (491)

Operation of the COMAND operating, display and control unit (A40/3) at the multifunction steering wheel (MFL) 

With the aid of the multifunction steering wheel (MFL) buttons and the multifunction display (A1p13) in the instrument cluster (A1), the following systems controlled by the COMAND operating, display and control unit (A40/3) can be operated and information on the systems can be displayed:

• Audio systems (e.g. radio)
• Navigation system
• Telephone

The entire exchange of data between the instrument cluster (A1) and the COMAND operating, display and control unit (A40/3) occurs over the Controller Area Network Bus Class B (interior) (CAN-B).

All actuations of the buttons on the multifunction steering wheel (MFL) are read in by the instrument cluster (A1). The instrument cluster (A1) links these signals with the system currently displayed on the multifunction display (A1p13) (audio, navigation, telephone).

This interpretation is necessary because the operation of the buttons depends on the current content of the multifunction display (A1p13). The interpreted data are subsequently sent from the instrument cluster (A1) to CAN-B and received by the COMAND operating, display and control unit (A40/3).

Changing the system shown on the multifunction display (A1p13) does not have an effect on what is being shown on the display of the COMAND operating, display and control unit (A40/3); however, what is shown on the display of the COMAND operating, display and control unit (A40/3) does have an effect on what is shown on the multifunction display (A1p13).

The instrument cluster (A1) receives the current time from the COMAND operating, display and control unit (A40/3) since this time is automatically received from the Global Positioning System (GPS). As such, the time setting does not need to be reset.