Diagnostic library

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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.

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 25–48 of 1228

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U0029Vehicle Communication Bus A PerformanceCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0029 concerns vehicle communication bus a performance. Learn what this fault indicates and where to begin diagnosis.U0030Vehicle Communication Bus A (+) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0030 concerns vehicle communication bus a (+) open. Learn what this fault indicates and where to begin diagnosis.U0031Vehicle Communication Bus A (+) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0031 concerns vehicle communication bus a (+) low. Learn what this fault indicates and where to begin diagnosis.U0032Vehicle Communication Bus A (+) HighCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0032 concerns vehicle communication bus a (+) high. Learn what this fault indicates and where to begin diagnosis.U0033Vehicle Communication Bus A (-) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0033 concerns vehicle communication bus a (-) open. Learn what this fault indicates and where to begin diagnosis.U0034Vehicle Communication Bus A (-) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0034 concerns vehicle communication bus a (-) low. Learn what this fault indicates and where to begin diagnosis.U0035Vehicle Communication Bus A (-) HighCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0035 concerns vehicle communication bus a (-) high. Learn what this fault indicates and where to begin diagnosis.U0036Vehicle Communication Bus A (-) shorted to Bus A (+)Check soonNetwork & Communication45–120 minutes for initial diagnosisU0036 concerns vehicle communication bus a (-) shorted to bus a (+). Learn what this fault indicates and where to begin diagnosis.U0037Vehicle Communication Bus BCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0037 concerns vehicle communication bus b. Learn what this fault indicates and where to begin diagnosis.U0038Vehicle Communication Bus B PerformanceCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0038 concerns vehicle communication bus b performance. Learn what this fault indicates and where to begin diagnosis.U0039Vehicle Communication Bus B (+) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0039 concerns vehicle communication bus b (+) open. Learn what this fault indicates and where to begin diagnosis.U0040Vehicle Communication Bus B (+) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0040 concerns vehicle communication bus b (+) low. Learn what this fault indicates and where to begin diagnosis.U0041Vehicle Communication Bus B (+) HighCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0041 concerns vehicle communication bus b (+) high. Learn what this fault indicates and where to begin diagnosis.U0042Vehicle Communication Bus B (-) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0042 concerns vehicle communication bus b (-) open. Learn what this fault indicates and where to begin diagnosis.U0043Vehicle Communication Bus B (-) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0043 concerns vehicle communication bus b (-) low. Learn what this fault indicates and where to begin diagnosis.U0044Vehicle Communication Bus B (-) HighCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0044 concerns vehicle communication bus b (-) high. Learn what this fault indicates and where to begin diagnosis.U0045Vehicle Communication Bus B (-) shorted to Bus B (+)Check soonNetwork & Communication45–120 minutes for initial diagnosisU0045 concerns vehicle communication bus b (-) shorted to bus b (+). Learn what this fault indicates and where to begin diagnosis.U0046Vehicle Communication Bus CCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0046 concerns vehicle communication bus c. Learn what this fault indicates and where to begin diagnosis.U0047Vehicle Communication Bus C PerformanceCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0047 concerns vehicle communication bus c performance. Learn what this fault indicates and where to begin diagnosis.U0048Vehicle Communication Bus C (+) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0048 concerns vehicle communication bus c (+) open. Learn what this fault indicates and where to begin diagnosis.U0049Vehicle Communication Bus C (+) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0049 concerns vehicle communication bus c (+) low. Learn what this fault indicates and where to begin diagnosis.U0050Vehicle Communication Bus C (+) HighCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0050 concerns vehicle communication bus c (+) high. Learn what this fault indicates and where to begin diagnosis.U0051Vehicle Communication Bus C (-) OpenCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0051 concerns vehicle communication bus c (-) open. Learn what this fault indicates and where to begin diagnosis.U0052Vehicle Communication Bus C (-) LowCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0052 concerns vehicle communication bus c (-) low. Learn what this fault indicates and where to begin diagnosis.