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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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Severity

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 1345–1368 of 2110

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P2445AIR System Pump Stuck Off Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP2445 relates to air system pump stuck off bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2446AIR System Pump Stuck On Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP2446 relates to air system pump stuck on bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2447AIR System Pump Stuck Off Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP2447 relates to air system pump stuck off bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2448AIR System High Air Flow Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP2448 relates to air system high air flow bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2449AIR System High Air Flow Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP2449 relates to air system high air flow bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P248AReductant Heater A Sense Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP248A relates to reductant heater a sense circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P248BReductant Heater A Sense Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP248B relates to reductant heater a sense circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P248CReductant Heater B Sense Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP248C relates to reductant heater b sense circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P248DReductant Heater B Sense Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP248D relates to reductant heater b sense circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P24CBReductant Tank Cap Switch CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24CB relates to reductant tank cap switch circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P24CCReductant Tank Cap Switch Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24CC relates to reductant tank cap switch circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P24CDReductant Tank Cap Switch Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24CD relates to reductant tank cap switch circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P24CEReductant Tank Cap Switch Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24CE relates to reductant tank cap switch circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P24CFReductant Tank Cap Switch Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24CF relates to reductant tank cap switch circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P24D2Reductant Heater A Sense CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24D2 relates to reductant heater a sense circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P24D3Reductant Heater B Sense CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24D3 relates to reductant heater b sense circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P24E1NH3 Sensor CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24E1 relates to nh3 sensor circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P24E2NH3 Sensor Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24E2 relates to nh3 sensor circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P24E3NH3 Sensor Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24E3 relates to nh3 sensor circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P24E4NH3 Sensor Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24E4 relates to nh3 sensor circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P24E5NH3 Sensor Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24E5 relates to nh3 sensor circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P24E6NH3 Sensor Heater Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24E6 relates to nh3 sensor heater circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P24E7NH3 Sensor Heater Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24E7 relates to nh3 sensor heater circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P24E8NH3 Sensor Heater Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP24E8 relates to nh3 sensor heater circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.