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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.

Check soon P · Powertrain Clear all

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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

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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 4321–4344 of 6682

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P2514Event Data Recorder Request Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2514 relates to event data recorder request circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P251APTO Enable Switch Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP251A relates to pto enable switch circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P251BPTO Enable Switch Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP251B relates to pto enable switch circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P251CPTO Enable Switch Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP251C relates to pto enable switch circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P251DPTO Engine Shutdown Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP251D relates to pto engine shutdown circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P251EPTO Engine Shutdown Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP251E relates to pto engine shutdown circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P251FPTO Engine Shutdown Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP251F relates to pto engine shutdown circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2525Vacuum Reservoir Pressure Sensor CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2525 relates to vacuum reservoir pressure sensor circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2526Vacuum Reservoir Pressure Sensor Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2526 relates to vacuum reservoir pressure sensor circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2527Vacuum Reservoir Pressure Sensor Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2527 relates to vacuum reservoir pressure sensor circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2528Vacuum Reservoir Pressure Sensor Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2528 relates to vacuum reservoir pressure sensor circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2529Vacuum Reservoir Pressure Sensor Circuit IntermittentCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2529 relates to vacuum reservoir pressure sensor circuit intermittent. Check the fault conditions and vehicle-specific procedure before replacing parts.P252AEngine Oil Quality Sensor CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP252A relates to engine oil quality sensor circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P252BEngine Oil Quality Sensor Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP252B relates to engine oil quality sensor circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P252CEngine Oil Quality Sensor Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP252C relates to engine oil quality sensor circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P252DEngine Oil Quality Sensor Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP252D relates to engine oil quality sensor circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P252EEngine Oil Quality Sensor Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP252E relates to engine oil quality sensor circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P252FEngine Oil Level Too HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP252F relates to engine oil level too high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2530Ignition Switch Run Position CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2530 relates to ignition switch run position circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2531Ignition Switch Run Position Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2531 relates to ignition switch run position circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2532Ignition Switch Run Position Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2532 relates to ignition switch run position circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2533Ignition Switch On/Start Position CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2533 relates to ignition switch on/start position circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2534Ignition Switch On/Start Position Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2534 relates to ignition switch on/start position circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2535Ignition Switch On/Start Position Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2535 relates to ignition switch on/start position circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.