How to Use OBD-II Data to Diagnose a Check Engine Light
No matter what's on the hood, an ECM sets a check engine light the same way, and there are only four things that can make a car run badly: an engine mechanical problem, an engine breathing problem or an ignition or fuel injection issue.
That's the filter. From there, the OBD-II modes do the rest. Freeze frame data shows you what the car was doing when the code set, Mode 06 monitor tests confirm whether your fix actually worked and pending DTCs flag problems before they become comebacks.
You don't need a premium scan tool to run this process. Full Global OBD-II capability, like the Autel MX900 offers, gets you every mode you need.
Watch the full video for a walkthrough of the 10 modes. For more information on the MX900, click here.
About the Author
Pete MeierPete Meier
Dorman Training Center Instructor and Former Creative Director, Technical | Vehicle Repair Group
Pete Meier is the former creative director, technical, for the Vehicle Repair Group with Endeavor Business Media. He is an ASE certified Master Technician with over 35 years of practical experience as a technician and educator, covering a wide variety of makes and models. He began writing for Motor Age as a contributor in 2006 and joined the magazine full-time as technical editor in 2010. Pete grew the Motor Age YouTube channel to more than 100,000 subscribers by delivering essential training videos for technicians at all levels.
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