Wire Testing Using Oscilloscope

Image Legend:
1 D+, blue
2 Terminal 1, black
3 FREQ OFF (+), blue
4 Oscillogram for correct signal passage
5 Oscillogram for disturbed signal passage

Wire Testing Using Oscilloscope:

Measuring instrument: BMW SERVICE TESTER

Test leads: FREQ OFF (+), blue; Terminal 1, black; D+, blue

Test principle:

A frequency is applied via one end of the wire to be tested which is then measured with the oscilloscope at the other end.

Test Procedure:

Connect universal test lead and leads for frequency testing to the BMW SERVICE TESTER.

Connect the blue D+ lead to the one end of the wire to be tested, the black terminal 1 and the blue FREQ OFF + lead to the other end.

Select *M* for multimeter, "22" for oscilloscope, "13" for frequency output. Apply any frequency and press acknowledgement button twice.

Move the wire back and forth during testing.

If the wire is OK., the oscilloscope will indicate a square-wave signal with a uniform progression. In the case of fault, the signal will be interrupted irregularly.