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
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.
Quick browse
Choose a vehicle system
FiltersSeverity · family
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 505–528 of 1016
P21F5Fuel Control System B Too Rich Off Idle Bank 1Check soonFuel System30–120 minutes for initial diagnosisP21F6Fuel Control System B Too Lean Off Idle Bank 2Check soonFuel System30–120 minutes for initial diagnosisP21F7Fuel Control System B Too Rich Off Idle Bank 2Check soonFuel System30–120 minutes for initial diagnosisP21F8Fuel Control System B Too Lean at Idle Bank 1Check soonFuel System30–120 minutes for initial diagnosisP21F9Fuel Control System B Too Rich at Idle Bank 1Check soonFuel System30–120 minutes for initial diagnosisP21FAFuel Control System B Too Lean at Idle Bank 2Check soonFuel System30–120 minutes for initial diagnosisP21FBFuel Control System B Too Rich at Idle Bank 2Check soonFuel System30–120 minutes for initial diagnosisP21FCFuel Control System B Too Lean at Higher Load Bank 1Check soonFuel System30–120 minutes for initial diagnosisP21FDFuel Control System B Too Rich at Higher Load Bank 1Check soonFuel System30–120 minutes for initial diagnosisP21FEFuel Control System B Too Lean at Higher Load Bank 2Check soonFuel System30–120 minutes for initial diagnosisP21FFFuel Control System B Too Rich at Higher Load Bank 2Check soonFuel System30–120 minutes for initial diagnosisP224CAlternative Fuel Tank Shutoff Valve A Control Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP224DAlternative Fuel Tank Shutoff Valve A Control Circuit Performance/Stuck OffCheck soonFuel System30–120 minutes for initial diagnosisP224EAlternative Fuel Tank Shutoff Valve A Control Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP224FAlternative Fuel Tank Shutoff Valve A Control Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP2264Water in Fuel Sensor A CircuitCheck soonFuel System30–120 minutes for initial diagnosisP2265Water in Fuel Sensor A Circuit Range/PerformanceCheck soonFuel System30–120 minutes for initial diagnosisP2266Water in Fuel Sensor A Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP2267Water in Fuel Sensor A Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP2268Water in Fuel Sensor A Circuit IntermittentCheck soonFuel System30–120 minutes for initial diagnosisP2269Water in Fuel Condition - Sensor ACheck soonFuel System30–120 minutes for initial diagnosisP226AWater in Fuel Lamp Control CircuitCheck soonFuel System30–120 minutes for initial diagnosisP2283Injector Control Pressure Sensor CircuitCheck soonFuel System30–120 minutes for initial diagnosisP2284Injector Control Pressure Sensor Circuit Range/PerformanceCheck soonFuel System30–120 minutes for initial diagnosis