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
Find codes by symptomChoose what you notice to search matching code guides.
Rough idle or shakingVibration while stoppedHard to startLong cranking or no-startEngine stallsCuts out at idle or on the roadHesitates or loses powerSlow response when acceleratingBattery light is onCharging system warningHarsh gear changesDelayed or rough shifting
A symptom can have several causes. Treat matching codes as clues and follow the diagnostic checks in each guide.
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These are generic OBD2 definitions. Exact make, model, engine, and year compatibility will appear after vehicle-fitment data is added.
Diagnostic codes
Showing 841–864 of 987
P3427Cylinder 4 Deactivation/Intake Valve Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP3428Cylinder 4 Deactivation/Intake Valve Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP3429Cylinder 4 Exhaust Valve Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP3430Cylinder 4 Exhaust Valve Control Circuit PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP3431Cylinder 4 Exhaust Valve Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP3432Cylinder 4 Exhaust Valve Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP3433Cylinder 5 Deactivation/Intake Valve Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP3434Cylinder 5 Deactivation/Intake Valve Control Circuit PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP3435Cylinder 5 Deactivation/Intake Valve Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP3436Cylinder 5 Deactivation/Intake Valve Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP3437Cylinder 5 Exhaust Valve Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP3438Cylinder 5 Exhaust Valve Control Circuit PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP3439Cylinder 5 Exhaust Valve Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP3440Cylinder 5 Exhaust Valve Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP3441Cylinder 6 Deactivation/Intake Valve Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP3442Cylinder 6 Deactivation/Intake Valve Control Circuit PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP3443Cylinder 6 Deactivation/Intake Valve Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP3444Cylinder 6 Deactivation/Intake Valve Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP3445Cylinder 6 Exhaust Valve Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP3446Cylinder 6 Exhaust Valve Control Circuit PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP3447Cylinder 6 Exhaust Valve Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP3448Cylinder 6 Exhaust Valve Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP3449Cylinder 7 Deactivation/Intake Valve Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP3450Cylinder 7 Deactivation/Intake Valve Control Circuit PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosis