GF82.90-P-3001T Scanning Of Switch Positions, Function

GF82.90-P-3001T Scanning Of Switch Positions, Function

15.03.07 The document has been updated to this date and will no longer be subject to revision.

Component Identification:

Multifunction steering wheel (MFL)
The control signals are transferred voltage-coded via the fanfare horns and airbag clock spring contact (A45) to the steering column module (N80).
From the steering column module (N80), the transfer takes place via the Controller Area Network bus class B (interior) (CAN-B).

Priorities
If a number of buttons is actuated simultaneously within the left multifunction steering wheel button group (S110) or right multifunction steering wheel button group (S111), only one function is activated by the instrument cluster (A1). This requires different priorities for the various functions within one button group.

Allocation of priority ranks within the right multifunction steering wheel button group (S111):
^ Fanfare horn pushbutton (S111s5)
^ Accept/terminate phone call button (S111s3)
^ Pushbutton + and -, specific function setting and volume control (S111s1)

Allocation of priority ranks within the left multifunction steering wheel button group (S110):
^ Fanfare horn pushbutton (S110s5)
^ System select pushbutton (S110s3)
^ Scroll forward/back pushbutton (S110s1)

Preparation of button statuses on multifunction steering wheel
The operation of the multifunction steering wheel buttons partially depends on the current contents of the multifunction display (A1p13). For this reason, the button statuses in the instrument cluster (A1) are interpreted taking into account the current display contents.

Example
If the driver presses the "+" of the + and -button for setting of specific functions and volume control (S111s1) on the multifunction steering wheel, the volume of the sound system is usually increased.
If the multifunction display (A1p13), however, just indicates the setting of the time, then on pressing the button + and -, setting of specific functions and volume control (S111s1), the time is changed. The volume then remains unchanged.