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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

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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 1345–1368 of 1939

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P256CEngine Idle Speed Selector Sensor/Switch Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256C relates to engine idle speed selector sensor/switch circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P256DEngine Idle Speed Selector Sensor/Switch Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256D relates to engine idle speed selector sensor/switch circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P256EEngine Idle Speed Selector Sensor/Switch Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256E relates to engine idle speed selector sensor/switch circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P2578Turbocharger/Supercharger Speed Sensor A CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2578 relates to turbocharger/supercharger speed sensor a circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2579Turbocharger/Supercharger Speed Sensor A Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2579 relates to turbocharger/supercharger speed sensor a circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P257AVacuum Reservoir Control Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257A relates to vacuum reservoir control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P257BVacuum Reservoir Control Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257B relates to vacuum reservoir control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P257CVacuum Reservoir Control Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257C relates to vacuum reservoir control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P257DEngine Hood Switch Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257D relates to engine hood switch circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P257EEngine Hood Switch Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257E relates to engine hood switch circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P257FEngine Hood Switch Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257F relates to engine hood switch circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2580Turbocharger/Supercharger Speed Sensor A Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2580 relates to turbocharger/supercharger speed sensor a circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2581Turbocharger/Supercharger Speed Sensor A Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2581 relates to turbocharger/supercharger speed sensor a circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2582Turbocharger/Supercharger Speed Sensor A Circuit IntermittentCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2582 relates to turbocharger/supercharger speed sensor a circuit intermittent. Check the fault conditions and vehicle-specific procedure before replacing parts.P2586Turbocharger Boost Control Position Sensor B CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2586 relates to turbocharger boost control position sensor b circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2587Turbocharger Boost Control Position Sensor B Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2587 relates to turbocharger boost control position sensor b circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2588Turbocharger Boost Control Position Sensor B Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2588 relates to turbocharger boost control position sensor b circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2589Turbocharger Boost Control Position Sensor B Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2589 relates to turbocharger boost control position sensor b circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P258AVacuum Pump Control Circuit A/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP258A relates to vacuum pump control circuit a/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P258BVacuum Pump Control Circuit A Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP258B relates to vacuum pump control circuit a range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P258CVacuum Pump Control Circuit A LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP258C relates to vacuum pump control circuit a low. Check the fault conditions and vehicle-specific procedure before replacing parts.P258DVacuum Pump Control Circuit A HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP258D relates to vacuum pump control circuit a high. Check the fault conditions and vehicle-specific procedure before replacing parts.P258EPTO Enable Switch PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP258E relates to pto enable switch performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P258FTorque Management Request Output SignalCheck soonSensors & Electronics30–120 minutes for initial diagnosisP258F relates to torque management request output signal. Check the fault conditions and vehicle-specific procedure before replacing parts.