The oscillographs shown here only apply to belt buckle switches with 4-pin connectors. These switches have a 4-wire Hall sensor with voltage interface.
The 4-pin adapter lead 61 6 032 must be used for the measurement. The adapter lead must be attached to the connector on the seat belt buckle and the wiring harness. The multifunction cable MFK1 is connected to the adapter pin 1 (terminal 31) and adapter pin 3 (cable to MRS control unit). The oscilloscope is set by the test module.
Fig. 1: Seat belt not inserted in belt buckle
1: Signal form: Square-wave
2: Low level approx. 0.8 V
Fig. 2: Seat belt inserted in belt buckle
1: Signal form: Square-wave
2: Low level 0V
Fig. 3: Break
Belt buckle disconnected or line break
1: Signal form: Saw-tooth