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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.

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Engine1049 Emissions515 Fuel1016 Sensors & Electronics2110 Transmission866 Electrical & Charging1797 Body & Restraints193 Chassis & Brakes479 Network & Communication1228

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All severities9253 Low priority305 Check soon8256 Urgent621

Code family

All families9253 P · Powertrain7353 B · Body193 C · Chassis479 U · Network1228

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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 3985–4008 of 7353

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P21CCReductant Control Module Supply Voltage HighCheck soonElectrical & Charging System30–120 minutes for initial diagnosisP21CC relates to reductant control module supply voltage high. Check the fault conditions and vehicle-specific procedure before replacing parts.P21CDReductant Quality Module Supply Voltage LowCheck soonElectrical & Charging System30–120 minutes for initial diagnosisP21CD relates to reductant quality module supply voltage low. Check the fault conditions and vehicle-specific procedure before replacing parts.P21CEReductant Quality Module PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP21CE relates to reductant quality module performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P21CFCylinder 1 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21CF relates to cylinder 1 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D0Cylinder 2 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D0 relates to cylinder 2 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D1Cylinder 3 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D1 relates to cylinder 3 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D2Cylinder 4 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D2 relates to cylinder 4 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D3Cylinder 5 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D3 relates to cylinder 5 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D4Cylinder 6 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D4 relates to cylinder 6 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D5Cylinder 7 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D5 relates to cylinder 7 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D6Cylinder 8 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D6 relates to cylinder 8 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D7Cylinder 9 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D7 relates to cylinder 9 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D8Cylinder 10 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D8 relates to cylinder 10 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21D9Cylinder 11 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21D9 relates to cylinder 11 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21DACylinder 12 Injector B Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP21DA relates to cylinder 12 injector b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P21DBCylinder 1 Injector B Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP21DB relates to cylinder 1 injector b circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P21DCCylinder 1 Injector B Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP21DC relates to cylinder 1 injector b circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P21DDReductant Heater A Current Too LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP21DD relates to reductant heater a current too low. Check the fault conditions and vehicle-specific procedure before replacing parts.P21DECylinder 2 Injector B Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP21DE relates to cylinder 2 injector b circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P21DFCylinder 2 Injector B Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP21DF relates to cylinder 2 injector b circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P21E0Cylinder 3 Injector B Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP21E0 relates to cylinder 3 injector b circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P21E1Cylinder 3 Injector B Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP21E1 relates to cylinder 3 injector b circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P21E2Cylinder 4 Injector B Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP21E2 relates to cylinder 4 injector b circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P21E3Cylinder 4 Injector B Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP21E3 relates to cylinder 4 injector b circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.