Seat belt buckle switch

The belt buckle switches indicate whether the seat belts have been fastened or not. The seat belt buckle switches receive voltage from the Crash Safety Module (ACSM). The current consumption of the switch is the signal for the switch position (seat belt fastened or not fastened). The seat belt buckle switches are permanently monitored whenever power is present at Terminal 15 and the status is wake-up line ON. Whether or not the belt tensioner on the passenger's side is activated depends on the status signal of the seat belt buckle switch (seat belt fastened or not fastened). If the seat belt is inserted in the seat belt buckle switch, the belt tensioner is also activated, if needed (only with head-on or rear-end collision). If the front passenger seat is detected as occupied via the signals from the seat occupancy mat without the belt buckle switch sending a signal, a seat belt warning is issued.