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Your car's way of telling you something needs attention
The check engine light is part of your car's onboard diagnostics (OBD-II) system. It monitors engine performance and emissions.
Learn MoreWhen something goes wrong, your car stores a specific code (like P0420) that identifies the problem.
How to Read CodesSome issues are minor, others urgent. Understanding the code helps you make the right decision.
When to WorryFind common check engine codes for your vehicle
Camry, Corolla, RAV4, Tacoma
Civic, Accord, CR-V, Pilot
F-150, Escape, Explorer, Mustang
Silverado, Equinox, Malibu, Tahoe
Altima, Rogue, Sentra, Pathfinder
3 Series, 5 Series, X3, X5
C-Class, E-Class, GLC, GLE
Jetta, Passat, Tiguan, Atlas
Elantra, Sonata, Tucson, Santa Fe
Outback, Forester, Crosstrek, Impreza
The codes drivers see most often
Stop guessing. Get AI-powered diagnostics in seconds. TrunkMonkey analyzes your check engine light and tells you exactly what's wrong and what to do next.
Advanced machine learning analyzes your specific code and vehicle
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Works with every car from 1996 to present
Educational guides to help you understand what's happening
The most frequent reasons your check engine light comes on, from loose gas caps to serious engine problems.
Read GuideLearn which issues you can handle yourself and when you need professional help.
Get AdviceStep-by-step guide to using an OBD-II scanner and understanding what the codes mean.
Learn How