This video is to measure the resistance value of Lonsdor K518S and adapter cable. Do not plug in the power supply. The k518s host keeps the power off state, and the multimeter hits the diode position.
The red pen is placed at the obd line and the host connection, and the voltage of each pin of the obd jack of the connected car is measured. The second pin of the first row is 0, the second pin of the second row is 0, and the first row of 6, 7, and 8 pins is 0. If the measurement results are different, you need to purchase a new obd cable.