Scanning of switch positions, function - GF82.90-P-3001SM

MODEL 220.0 /1, 215.3 (except 220.074 /174 /179, 215.374 /379) as of 1.9.03 

The button presses on the multifunction steering wheel (MFL) are read in by the steering column module (N80) (voltage coded). Different resistors are connected in series upstream and downstream of the individual buttons. Pressing the buttons relays different voltages to the steering column module (N80). The steering column module (N80) interprets the button-related request from these voltages and can then generate and transmit an appropriate Class B (interior) Controller Area Network Bus (CAN-B) message.

Priorities 

If, within the left multifunction steering wheel button group (S110) or the right multifunction steering wheel button group (S111) several buttons are pressed simultaneously, the instrument cluster (A1) will always only activate one function. As a result, the different functions have different priority ranks.

Below, the buttons within the right multifunction steering wheel button group(S111) are arranged in descending priority order:

• Fanfare horn button (S111s5)
• Accept/terminate phone call button (S111s3)
• Buttons + and -for setting specific functions and volume control (S111s1)

The buttons within the left multifunction steering wheel button group (S111) are arranged in descending priority order:

• Fanfare horn button (S110s5)
• System select button (S110s3)
• Scroll forward/back button (S110s1)