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 193–216 of 305
P240AEVAP System Leak Detection Pump Heater Control Circuit/OpenLow priorityEmissions System30–120 minutes for initial diagnosisP240BEVAP System Leak Detection Pump Heater Control Circuit LowLow priorityEmissions System30–120 minutes for initial diagnosisP240CEVAP System Leak Detection Pump Heater Control Circuit HighLow priorityEmissions System30–120 minutes for initial diagnosisP2410Fuel Cap Sensor/Switch Circuit LowLow priorityFuel System30–120 minutes for initial diagnosisP2411Fuel Cap Sensor/Switch Circuit HighLow priorityFuel System30–120 minutes for initial diagnosisP2412Fuel Cap Sensor/Switch Circuit Intermittent/ErraticLow priorityFuel System30–120 minutes for initial diagnosisP2418EVAP System Switching Valve Control Circuit/OpenLow priorityEmissions System30–120 minutes for initial diagnosisP2419EVAP System Switching Valve Control Circuit LowLow priorityEmissions System30–120 minutes for initial diagnosisP2420EVAP System Switching Valve Control Circuit HighLow priorityEmissions System30–120 minutes for initial diagnosisP2421EVAP System Vent Valve Stuck OpenLow priorityEmissions System30–120 minutes for initial diagnosisP2422EVAP System Vent Valve Stuck ClosedLow priorityEmissions System30–120 minutes for initial diagnosisP2423HC Adsorption Catalyst Efficiency Below Threshold Bank 1Low priorityEmissions System30–120 minutes for initial diagnosisP2424HC Adsorption Catalyst Efficiency Below Threshold Bank 2Low priorityEmissions System30–120 minutes for initial diagnosisP2450EVAP System Switching Valve Performance/Stuck OpenLow priorityEmissions System30–120 minutes for initial diagnosisP2451EVAP System Switching Valve Stuck ClosedLow priorityEmissions System30–120 minutes for initial diagnosisP24B8EVAP System Leak Detection Pump Pressure Sensor CircuitLow priorityEmissions System30–120 minutes for initial diagnosisP24B9EVAP System Leak Detection Pump Pressure Sensor Circuit Range/PerformanceLow priorityEmissions System30–120 minutes for initial diagnosisP24BAEVAP System Leak Detection Pump Pressure Sensor Circuit LowLow priorityEmissions System30–120 minutes for initial diagnosisP24BBEVAP System Leak Detection Pump Pressure Sensor Circuit HighLow priorityEmissions System30–120 minutes for initial diagnosisP24BCEVAP System Leak Detection Pump Pressure Sensor Circuit IntermittentLow priorityEmissions System30–120 minutes for initial diagnosisP24BDEVAP System Leak Detection Pump Switching Valve Control Circuit/OpenLow priorityEmissions System30–120 minutes for initial diagnosisP24BEEVAP System Leak Detection Pump Switching Valve Control Circuit LowLow priorityEmissions System30–120 minutes for initial diagnosisP24BFEVAP System Leak Detection Pump Switching Valve Control Circuit HighLow priorityEmissions System30–120 minutes for initial diagnosisP24C0EVAP System Leak Detection Pump Switching Valve Stuck OnLow priorityEmissions System30–120 minutes for initial diagnosis