How to Understand OBD Codes
- 1). Hook up the OBD code reader to the data link connection in your vehicle. This diagnostic port can very by make and model, but it's usually on the driver's side and under the dashboard and steering wheel.
- 2). Turn the scanner on, if your brand of reader does not instantly come on when it senses a connection. Turn on your car next. You may need to either turn the electrical system on or start the engine. Once the diagnostic system and the reader have established a connection, the code will appear on the scanner's screen.
- 3). Look at the code on the screen and find the first character. If your vehicle was manufactured after 1996, your car will go by OBD-II standards, and the first character will be a letter of the alphabet. Codes from before 1996 may follow different standards, but the older ones are usually two- to three-digit numbers. These older codes are harder to "read" and you should should just look the number up.
- 4). Look at the first letter of the code. This letter has a specific meaning. "P" stands for "powertrain." "B" stands for "Body." "C" stands for "Chassis." "U" stands for "Network Communication. These letters correspond to where the problem is located.
- 5). Look at the number following the first letter. For all locations, "0" denotes a generic code as set forth by the Society of Automotive Engineers. A "1" denotes a code specific to the vehicle's manufacturer. If the code is generic, you can likely find a definition in your reader's user manual. However, your manual may not contain manufacturer trouble codes. For those, like with OBD-I and older codes, you may have to locate that information online.
- 6). Turn the vehicle off and unhook the scanner. Look up the trouble code, and then, you're going to have to make a decision on whether you have the expertise to fix the problem or not. In some cases, there may not be an easy DIY solution, and you should consult a professional mechanic.
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