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Overview: How To Use OBD-II Scanner to Check Engine Light Codes and What Type of Scanners Are There?

It's time to visit the service shop any time the "Check Engine" light on the dashboard starts to blink. It can also be discouraging to learn that the fuel cap was loose when the light first appeared and that you could have easily fixed it. Before we make the trip to the service center, life would be a lot simpler if we could figure out exactly what is wrong with the car.

OBD scanners are used by auto mechanics to identify issues with your vehicle. These are gadgets that fit into your car's OBD port and read the data there. In order to pinpoint the precise problem, whether it be an engine misfire, loose wires, or a change in oxygen, this data is analyzed.

There are a variety of different types of OBD scanners and there are two different generations of scanners, OBD-II and OBD-I. Each of these will cover two different generations of vehicles. OBD-II will cover years 1996 and newer while the OBD-I will cover 1995 and lower. There are also a number of scanners that range from a basic model that will simply give you the fault code that your vehicle is displaying to more advanced scanners that can program your vehicle's electronics. 

Regardless of the scanner you use, these practical tools are surprisingly simple to use. The OBD port, which is where a state emissions tester will insert their probe during your yearly vehicle inspection, is where you should attach your OBD2 scanner. The port is typically located next to or beneath the steering wheel column. If you can't find it, check your manual; it might be under the glove box, close to the center console, or close to the middle of the dashboard. The diagnostic trouble code, or DTC, will be read from the engine computer as soon as your scanner is connected. The letter that represents each system is followed by the four digits that identify the problem. There are codes for the chassis, body, and drivetrain.

Types of Fault Codes:

  • P: Powertrain
  • B: Body
  • C: Chassis
  • U: Network

Keep in mind that every Haynes Manual has a section on fault codes for reference. So you'll need to make sure you get the right one for your needs and your vehicle. If you already have a scanner, you might want the Haynes OBD-II Techbook to teach you everything you need to know about the OBD system. Check out the video and you know what kind of scanners there are today and the basics of using one!