Vehicle Diagnostic equipment auto-on

The way to Perform Diagnostics Tests Working with a Scanner on a Vehicle's Engine 1Some scanners power up by themselves and automatically retrieve codes, while others must be manually switched on with a "retrieve" command entered. Some only display codes, while others can interact with a computer through a USB cable.

Also, while acquainting yourself with a scanner and its manual, bookmark the lists of OBD-II code definitions. You will need to reference them.2Find the diagnostic data link connection in your automobile. For most vehicles, this is found beneath the dashboard and between the gas pedal and left panel. In some vehicles, this outlet is exposed, while others are not. You are looking for a 16-pin receptor port usually molded out of black plastic.3Hook your scanner up to the diagnostic data connection. Slight variations in performing tests will start here because of differences in OBD-II scanners.

The following are general steps to complete a test.4Turn on your automobile. Some scanners will require only power, but others might need the engine cranked. If you are employing a scanner that does not feature an "auto-on Vehicle Diagnostic equipment," switch it on and key in a "retrieve" command. It will take a second for codes to appear on the scanner.5Scroll through the codes and differentiate between what is " auto diagnostics software;trouble" and what is "pending." Always attend to trouble codes first.

Consult the scanner's manual for coding definitions. Many scanners' manuals, however, only have generic codes that apply to all OBD-II vehicles. Manufacturers have supplemental codes particular to their vehicles. If you cannot find the code description in a manual, you might need to search for the definitions online.6Turn off the scanner and car. Open the hood and look into the engine compartment to examine areas that need further scrutiny. However, if the scanner reported something unfamiliar, take the car to a mechanic.