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

MODEL 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. The requests from the steering wheel gear shifter PLUS switch (S111/1) and the steering wheel gear shifter MINUS switch (S110/1) are also read in voltage-coded. The steering column module (N80) receives the requests from the steering wheel gear shifter PLUS switch (S111/1) and the steering wheel gear shifter MINUS switch (S110/1) and relays them to the electronic selector lever module control unit (N15/5) via discrete cabling.

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 listed in descending priority order:

• Fanfare horn button (S111s5)
• Steering wheel gear shifter PLUS (S111/1)
• Accept/terminate phone call button (S111s3)
• Buttons + and -for setting specific functions and volume control (S111s1)

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

• Fanfare horn button (S110s5)
• Steering wheel gear shifter MINUS (S110/1)
• System select button (S110s3)
• Scroll forward/back button (S110s1)