Diagnostic library

Find an OBD2 code

Search the code from your scanner, then narrow the library by system, severity, or code family.

9,253 diagnostic guides

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Find codes by symptomChoose what you notice to search matching code guides.

Rough idle or shakingVibration while stopped Hard to startLong cranking or no-start Engine stallsCuts out at idle or on the road Hesitates or loses powerSlow response when accelerating Battery light is onCharging system warning Harsh gear changesDelayed or rough shifting

A symptom can have several causes. Treat matching codes as clues and follow the diagnostic checks in each guide.

Check soon U · Network Clear all

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Engine1049 Emissions515 Fuel1016 Sensors & Electronics2110 Transmission866 Electrical & Charging1797 Body & Restraints193 Chassis & Brakes479 Network & Communication1228

FiltersSeverity · family

Severity

All severities9253 Low priority305 Check soon8256 Urgent621

Code family

All families9253 P · Powertrain7353 B · Body193 C · Chassis479 U · Network1228

Vehicle coverage

These are generic OBD2 definitions. Exact make, model, engine, and year compatibility will appear after vehicle-fitment data is added.

Diagnostic codes

Showing 49–72 of 1223

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U0056Vehicle Communication Bus D PerformanceCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0056 concerns vehicle communication bus d performance. Learn what this fault indicates and where to begin diagnosis.U0057Vehicle Communication Bus D (+) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0057 concerns vehicle communication bus d (+) open. Learn what this fault indicates and where to begin diagnosis.U0058Vehicle Communication Bus D (+) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0058 concerns vehicle communication bus d (+) low. Learn what this fault indicates and where to begin diagnosis.U0059Vehicle Communication Bus D (+) HighCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0059 concerns vehicle communication bus d (+) high. Learn what this fault indicates and where to begin diagnosis.U0060Vehicle Communication Bus D (-) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0060 concerns vehicle communication bus d (-) open. Learn what this fault indicates and where to begin diagnosis.U0061Vehicle Communication Bus D (-) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0061 concerns vehicle communication bus d (-) low. Learn what this fault indicates and where to begin diagnosis.U0062Vehicle Communication Bus D (-) HighCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0062 concerns vehicle communication bus d (-) high. Learn what this fault indicates and where to begin diagnosis.U0063Vehicle Communication Bus D (-) shorted to Bus D (+)Check soonNetwork & Communication45–120 minutes for initial diagnosisU0063 concerns vehicle communication bus d (-) shorted to bus d (+). Learn what this fault indicates and where to begin diagnosis.U0064Vehicle Communication Bus ECheck soonNetwork & Communication45–120 minutes for initial diagnosisU0064 concerns vehicle communication bus e. Learn what this fault indicates and where to begin diagnosis.U0065Vehicle Communication Bus E PerformanceCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0065 concerns vehicle communication bus e performance. Learn what this fault indicates and where to begin diagnosis.U0066Vehicle Communication Bus E (+) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0066 concerns vehicle communication bus e (+) open. Learn what this fault indicates and where to begin diagnosis.U0067Vehicle Communication Bus E (+) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0067 concerns vehicle communication bus e (+) low. Learn what this fault indicates and where to begin diagnosis.U0068Vehicle Communication Bus E (+) HighCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0068 concerns vehicle communication bus e (+) high. Learn what this fault indicates and where to begin diagnosis.U0069Vehicle Communication Bus E (-) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0069 concerns vehicle communication bus e (-) open. Learn what this fault indicates and where to begin diagnosis.U0070Vehicle Communication Bus E (-) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0070 concerns vehicle communication bus e (-) low. Learn what this fault indicates and where to begin diagnosis.U0071Vehicle Communication Bus E (-) HighCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0071 concerns vehicle communication bus e (-) high. Learn what this fault indicates and where to begin diagnosis.U0072Vehicle Communication Bus E (-) shorted to Bus E (+)Check soonNetwork & Communication45–120 minutes for initial diagnosisU0072 concerns vehicle communication bus e (-) shorted to bus e (+). Learn what this fault indicates and where to begin diagnosis.U0073Control Module Communication Bus A OffCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0073 concerns control module communication bus a off. Learn what this fault indicates and where to begin diagnosis.U0074Control Module Communication Bus B OffCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0074 concerns control module communication bus b off. Learn what this fault indicates and where to begin diagnosis.U0075Control Module Communication Bus C OffCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0075 concerns control module communication bus c off. Learn what this fault indicates and where to begin diagnosis.U0076Control Module Communication Bus D OffCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0076 concerns control module communication bus d off. Learn what this fault indicates and where to begin diagnosis.U0077Control Module Communication Bus E OffCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0077 concerns control module communication bus e off. Learn what this fault indicates and where to begin diagnosis.U0078Control Module Communication Bus F OffCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0078 concerns control module communication bus f off. Learn what this fault indicates and where to begin diagnosis.U0079Control Module Communication Bus G OffCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0079 concerns control module communication bus g off. Learn what this fault indicates and where to begin diagnosis.