Model 171.4 (except 171.473) except CODE (428) Steering wheel shift buttons - GF82.90-P-3001SK

Model 171.4 (except 171.473) except CODE (428) Steering wheel shift buttons 

The button presses on the multifunction steering wheel (MFL) are read in voltage-coded by the steering column module (N80). 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. Allocation of priority ratings within the right multifunction steering wheel button group (S111) (in descending order):

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

Allocation of priority ratings within the left multifunction steering wheel button group (S110) (in descending order):

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