Since 1996, in the USA all cars are required to be equipped with an OBD 2 system by law. The OBD 2 system monitors a car's performance and notices the driver of current problems and potential problems of the car. An OBD 2 reader has to be connected to the car so as to recover the Diagnostic Trouble Codes which short for DTC generated by the OBD 2 system.
To complete the work as below, you may need OBD 2 scanner, OBD 2 reader cable, Laptop computer, Converter, OBD 2 software and USB, RS-232C or Bluetooth connector.
Firstly, decide whether your car is OBD 2 compliant. A car that is OBD 2 compliant will have a female 16-pin connector on the driver's side near the center system. Petrol cars manufactured since 2001 and diesel cars manufactured since 2004 should have this connector.
Prepare the equipment you will need. Relying on the type of OBD
2 scanner you will be using, you will need a personal OBD 2 code reader and a cable, or a computer with OBD 2 software, a converter and connectors. For your safety, your car engine should be powered off when you link your OBD 2 scanner to you car.
Secondly, find out the location of 16-pin connector. This connector is not always easy to find but it will be inside the car and not under the hood. Some places where car manufacturers mount this connector contain: under the steering wheel, the driver's foot well, the area between the driver and passenger seat, behind the ash tray, under the passenger seat, and over the passenger door.
Thirdly, check the connector for the available pins. The connector must contain pins 4 and 5 for grounding and pin 16 for power supply from the battery. The other pins are present for the kinds of protocols required for different car brands, containing SAE J1850, ISO 9141-2, and ISO 14230 and CAN bus.
Fourthly, link your OBD 2 code reader to you car. Insert the end of the contained cable with the 16-pin connector to the female 16-pin port, and then connect the other end of the cable to the OBD 2 scanner.
Finally, you can use your laptop computer serve as an OBD 2 code reader. You can link your computer to your car with the use of a USB, RS-232C or Bluetooth connector. Except connectors, you will need the OBD 2 software to deal with the information from your car and converters to modulate the voltage. If you have any query, please do not hesitate to contact me.