Introduce the PINs of OBDII interface and cheap way to check them

[jellyfish1234]

There are 16 pins of OBDII interface, from top to bottom, from left to right, mark them as 1-16.
PIN4 is Chassis Ground
Pin 5 - Signal Ground
Pin 6 - CAN High (J-2284)
Pin 7 - ISO 9141-2 K Line
Pin 10 - J1850 Bus
Pin 14 - CAN Low (J-2284)
Pin 15 - ISO 9141-2 L Line
Pin 16 - 12V Battery Power

Sometimes when you connect OBDII code reader to your car OBD interface, it doesn’t work, but works on other cars, you may need to check the OBDII pins, especially PIN4 and PIN16, to check that you don’t need to drive to the dealer’s. Just use multi-meter to test PIN voltage, the normal range of 6PIN should be between 2.5-3V, 14PIN should be between 2.0-2.5V. If these two are not in normal condition, even manufacture tool is useless, the problem is not code reader but that car’s OBDII interface.