Diagnostic library
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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 937–960 of 6682
P04C9Fuel Fill Door Open Request Sensor/Switch Performance/Stuck OffCheck soonFuel System30–120 minutes for initial diagnosisP04CAFuel Fill Door Open Request Sensor/Switch Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP04CBFuel Fill Door Open Request Sensor/Switch Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP04CCFuel Fill Door Open Request Sensor/Switch Circuit Intermittent/ErraticCheck soonFuel System30–120 minutes for initial diagnosisP04CDFuel Fill Door Open Request Sensor/Switch Stuck OnCheck soonFuel System30–120 minutes for initial diagnosisP04CEEGR Temperature Sensor C CircuitCheck soonEmissions System30–120 minutes for initial diagnosisP04CFEGR Temperature Sensor C Circuit Range/PerformanceCheck soonEmissions System30–120 minutes for initial diagnosisP04D0EGR Temperature Sensor C Circuit LowCheck soonEmissions System30–120 minutes for initial diagnosisP04D1EGR Temperature Sensor C Circuit HighCheck soonEmissions System30–120 minutes for initial diagnosisP04D2EGR Temperature Sensor C Circuit Intermittent/ErraticCheck soonEmissions System30–120 minutes for initial diagnosisP04D3Exhaust Brake Input CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04D4Exhaust Brake Input Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04D5Exhaust Brake Input Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04D6Exhaust Brake Input Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04D7Exhaust Brake Input Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04D8Excessive Time To Enter Closed Loop EGR ControlCheck soonEmissions System30–120 minutes for initial diagnosisP04D9Closed Loop EGR Control At Limit - Flow Too LowCheck soonEmissions System30–120 minutes for initial diagnosisP04DAClosed Loop EGR Control At Limit - Flow Too HighCheck soonEmissions System30–120 minutes for initial diagnosisP04DBCrankcase Ventilation System DisconnectedCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04DCFuel Fill Door Position Sensor/Switch Circuit Range/PerformanceCheck soonFuel System30–120 minutes for initial diagnosisP04DDCold Start EGR A Flow Insufficient DetectedCheck soonEmissions System30–120 minutes for initial diagnosisP04DECold Start EGR A Flow Excessive DetectedCheck soonEmissions System30–120 minutes for initial diagnosisP04E1Crankcase Ventilation Hose Connection Sensor CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04E2Crankcase Ventilation Hose Connection Sensor Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosis