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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 25–48 of 2110

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P003ATurbocharger/Supercharger Boost Control A Position Exceeded Learning LimitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP003A relates to turbocharger/supercharger boost control a position exceeded learning limit. Check the fault conditions and vehicle-specific procedure before replacing parts.P003BTurbocharger/Supercharger Boost Control B Position Exceeded Learning LimitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP003B relates to turbocharger/supercharger boost control b position exceeded learning limit. Check the fault conditions and vehicle-specific procedure before replacing parts.P0040O2 Sensor Signals Swapped Bank 1 Sensor 1/Bank 2 Sensor 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP0040 relates to o2 sensor signals swapped bank 1 sensor 1/bank 2 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0041O2 Sensor Signals Swapped Bank 1 Sensor 2/Bank 2 Sensor 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP0041 relates to o2 sensor signals swapped bank 1 sensor 2/bank 2 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P0042HO2S Heater Control Circuit Bank 1 Sensor 3Low prioritySensors & Electronics30–120 minutes for initial diagnosisP0042 relates to ho2s heater control circuit bank 1 sensor 3. Check the fault conditions and vehicle-specific procedure before replacing parts.P0043HO2S Heater Control Circuit Low Bank 1 Sensor 3Low prioritySensors & Electronics30–120 minutes for initial diagnosisP0043 relates to ho2s heater control circuit low bank 1 sensor 3. Check the fault conditions and vehicle-specific procedure before replacing parts.P0044HO2S Heater Control Circuit High Bank 1 Sensor 3Low prioritySensors & Electronics30–120 minutes for initial diagnosisP0044 relates to ho2s heater control circuit high bank 1 sensor 3. Check the fault conditions and vehicle-specific procedure before replacing parts.P0045Turbocharger/Supercharger Boost Control A Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0045 relates to turbocharger/supercharger boost control a circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P0046Turbocharger/Supercharger Boost Control A Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0046 relates to turbocharger/supercharger boost control a circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0047Turbocharger/Supercharger Boost Control A Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0047 relates to turbocharger/supercharger boost control a circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P0048Turbocharger/Supercharger Boost Control A Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0048 relates to turbocharger/supercharger boost control a circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P0049Turbocharger/Supercharger A Turbine OverspeedUrgentSensors & Electronics30–120 minutes for initial diagnosisP0049 relates to turbocharger/supercharger a turbine overspeed. Check the fault conditions and vehicle-specific procedure before replacing parts.P004ATurbocharger/Supercharger Boost Control B Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP004A relates to turbocharger/supercharger boost control b circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P004BTurbocharger/Supercharger Boost Control B Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP004B relates to turbocharger/supercharger boost control b circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P004CTurbocharger/Supercharger Boost Control B Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP004C relates to turbocharger/supercharger boost control b circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P004DTurbocharger/Supercharger Boost Control B Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP004D relates to turbocharger/supercharger boost control b circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P004ETurbocharger/Supercharger Boost Control A Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP004E relates to turbocharger/supercharger boost control a circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P004FTurbocharger/Supercharger Boost Control B Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP004F relates to turbocharger/supercharger boost control b circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P0050Heated Oxygen Sensor Heater Control Circuit Bank 2 Sensor 1Low prioritySensors & Electronics45–120 minutes for initial diagnosisP0050 means Heated Oxygen Sensor Heater Control Circuit Bank 2 Sensor 1. Learn the likely symptoms, causes, safety implications, and a practical diagnostic order.P0056Heated Oxygen Sensor Heater Control Circuit Bank 2 Sensor 2Low prioritySensors & Electronics45–120 minutes for initial diagnosisP0056 means Heated Oxygen Sensor Heater Control Circuit Bank 2 Sensor 2. Learn the likely symptoms, causes, safety implications, and a practical diagnostic order.P006AMAP - Mass or Volume Air Flow Correlation Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP006A relates to map - mass or volume air flow correlation bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P006BMAP - Exhaust Pressure CorrelationCheck soonSensors & Electronics30–120 minutes for initial diagnosisP006B relates to map - exhaust pressure correlation. Check the fault conditions and vehicle-specific procedure before replacing parts.P006CMAP - Turbocharger/Supercharger Inlet Pressure CorrelationCheck soonSensors & Electronics30–120 minutes for initial diagnosisP006C relates to map - turbocharger/supercharger inlet pressure correlation. Check the fault conditions and vehicle-specific procedure before replacing parts.P006DBarometric Pressure - Turbocharger/Supercharger Inlet Pressure Correlation Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP006D relates to barometric pressure - turbocharger/supercharger inlet pressure correlation bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.