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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 985–1008 of 6682

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P0508Idle Air Control System Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP0508 indicates a fault related to idle air control system circuit low. Learn the likely causes and a practical diagnostic order before replacing parts.P0509Idle Air Control System Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP0509 indicates a fault related to idle air control system circuit high. Learn the likely causes and a practical diagnostic order before replacing parts.P050ACold Start Idle Control System PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP050A relates to cold start idle control system performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P050BCold Start Ignition Timing PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP050B relates to cold start ignition timing performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P050CCold Start Engine Coolant Temperature PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP050C relates to cold start engine coolant temperature performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P050DCold Start Rough IdleCheck soonSensors & Electronics30–120 minutes for initial diagnosisP050D relates to cold start rough idle. Check the fault conditions and vehicle-specific procedure before replacing parts.P050ECold Start Engine Exhaust Temperature Too LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP050E relates to cold start engine exhaust temperature too low. Check the fault conditions and vehicle-specific procedure before replacing parts.P050FBrake Assist Vacuum Too LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP050F relates to brake assist vacuum too low. Check the fault conditions and vehicle-specific procedure before replacing parts.P0510Closed Throttle Position Switch MalfunctionCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0510 indicates a fault related to closed throttle position switch malfunction. Learn the likely causes and a practical diagnostic order before replacing parts.P0511Idle Air Control CircuitCheck soonEngine Problems30–120 minutes for initial diagnosisP0511 indicates a fault related to idle air control circuit. Learn the likely causes and a practical diagnostic order before replacing parts.P0512Starter Request CircuitCheck soonElectrical & Charging System30–120 minutes for initial diagnosisP0512 indicates a fault related to starter request circuit. Learn the likely causes and a practical diagnostic order before replacing parts.P0513Incorrect Immobilizer KeyCheck soonElectrical & Charging System30–120 minutes for initial diagnosisP0513 indicates a fault related to incorrect immobilizer key. Learn the likely causes and a practical diagnostic order before replacing parts.P0514Battery Temperature Sensor Circuit Range/PerformanceCheck soonElectrical & Charging System30–120 minutes for initial diagnosisP0514 indicates a fault related to battery temperature sensor circuit range/performance. Learn the likely causes and a practical diagnostic order before replacing parts.P0515Battery Temperature Sensor CircuitCheck soonElectrical & Charging System30–120 minutes for initial diagnosisP0515 indicates a fault related to battery temperature sensor circuit. Learn the likely causes and a practical diagnostic order before replacing parts.P0516Battery Temperature Sensor Circuit LowCheck soonElectrical & Charging System30–120 minutes for initial diagnosisP0516 indicates a fault related to battery temperature sensor circuit low. Learn the likely causes and a practical diagnostic order before replacing parts.P0517Battery Temperature Sensor Circuit HighCheck soonElectrical & Charging System30–120 minutes for initial diagnosisP0517 indicates a fault related to battery temperature sensor circuit high. Learn the likely causes and a practical diagnostic order before replacing parts.P0518Idle Air Control Circuit IntermittentCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0518 relates to idle air control circuit intermittent. Check the fault conditions and vehicle-specific procedure before replacing parts.P0519Idle Air Control System PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0519 relates to idle air control system performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P051ACrankcase Pressure Sensor A CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP051A relates to crankcase pressure sensor a circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P051BCrankcase Pressure Sensor A Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP051B relates to crankcase pressure sensor a circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P051CCrankcase Pressure Sensor A Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP051C relates to crankcase pressure sensor a circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P051DCrankcase Pressure Sensor A Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP051D relates to crankcase pressure sensor a circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P051ECrankcase Pressure Sensor A Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP051E relates to crankcase pressure sensor a circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P051FPCV Filter RestrictionCheck soonSensors & Electronics30–120 minutes for initial diagnosisP051F relates to pcv filter restriction. Check the fault conditions and vehicle-specific procedure before replacing parts.