Signal Processing Module: Description and Operation

GF82.85-P-3008P Data Transfer Between COMAND And Instrument Cluster, Function
- with CODE (352a) COMAND operating and display system
- except CODE (491) U.S. version
- except CODE (498) Japanese version

Component Identification:

Operation of the COMAND operating, display and control unit (A40/3) on the multifunction steering wheel (MFL)
With the aid of the multifunction steering wheel (MFL) button and the multifunction display (A1p13) of 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 displayed:
^ Audio systems (e.g. radio, CD changer, etc.)
^ Navigation system
^ Telephone

The total data exchange between the instrument cluster (A1) and the COMAND operating, display and control unit (A40/3) is performed over the Controller Area Network bus Class B (interior) (CAN-B).
All buttons pressed on the multifunction steering wheel (MFL) are read in by the instrument cluster (A1) voltage coded. The instrument cluster (A1) links these signals with the systems 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 then transferred from the instrument cluster (A1) to the CAN-B and received by the COMAND operating, display and control unit (A40/3).
The change of the system to the multifunction display (A1p13) does not affect what is shown on the display of the COMAND operating, display and control unit (A40/3), but what is shown on the display of the COMAND operating, display and control unit (A40/3) influences the multifunction display (A1p13).

The instrument cluster (A1) receives the current time from the COMAND operating, display and control unit (A40/3) since this information is automatically received via GPS.