How to Interpret a Vehicle Diagnostic Reading

Most all newer vehicles come equipped with an on-board diagnostic system that alerts the driver when there is a problem within the vehicle. Once a problem arises, generally the service engine light will come on and stay on until the problem is fixed and the code erased from the system. Other problematic codes can arise from the transmission, ABS brake system and the vehicle's drive train. Use an OBD-II scanner to locate the specific code. After locating the code, obtain a service manual for the vehicle to determine the code's meaning.

Instructions

1

Obtain an automotive repair manual for the vehicle's specific make and model. Most all major auto parts stores carry automotive manuals for the majority of vehicles. The manual will include the diagnostic codes and the meaning for each code.

2

Connect the scanner to the diagnostic port inside of the vehicle. Turn the ignition key to the accessory position. Some vehicles may require the engine to be running or the ignition key to be in the "Off" position before the scanner will work. Find this information and the location of the OBD-II scanner port in a vehicle's maintenance and repair manual.

3

Turn the scanner on and follow all of the on-screen prompts to begin the diagnostic process of finding the code. The scanner will prompt you for all of the vehicle's information such as the make and model, engine size and other information. Once the code number is on the screen, write down the code number on a notepad.

4

Refer to the automotive repair manual for the meaning of the code. Look up the diagnostic code section inside of the manual and cross-reference the code number to the problem. Each code number represents a specific problem within the vehicle and the manual will show the meanings for each code number. Repair the problem before erasing the code.