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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 1105–1128 of 7353

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P04EAEVAP System Small Leak Detected - Fuel Tank SideLow priorityEmissions System30–120 minutes for initial diagnosisP04EA relates to evap system small leak detected - fuel tank side. Check the fault conditions and vehicle-specific procedure before replacing parts.P04EBEVAP System Small Leak Detected - Fresh Air SideLow priorityEmissions System30–120 minutes for initial diagnosisP04EB relates to evap system small leak detected - fresh air side. Check the fault conditions and vehicle-specific procedure before replacing parts.P04ECEVAP System Large Leak Detected - Fuel Tank SideLow priorityEmissions System30–120 minutes for initial diagnosisP04EC relates to evap system large leak detected - fuel tank side. Check the fault conditions and vehicle-specific procedure before replacing parts.P04EDEVAP System Large Leak Detected - Fresh Air SideLow priorityEmissions System30–120 minutes for initial diagnosisP04ED relates to evap system large leak detected - fresh air side. Check the fault conditions and vehicle-specific procedure before replacing parts.P04EEEVAP System Very Small Leak Detected - Fuel Tank SideLow priorityEmissions System30–120 minutes for initial diagnosisP04EE relates to evap system very small leak detected - fuel tank side. Check the fault conditions and vehicle-specific procedure before replacing parts.P04EFEVAP System Very Small Leak Detected - Fresh Air SideLow priorityEmissions System30–120 minutes for initial diagnosisP04EF relates to evap system very small leak detected - fresh air side. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F0EVAP System High Load Purge Line A PerformanceLow priorityEmissions System30–120 minutes for initial diagnosisP04F0 relates to evap system high load purge line a performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F1EVAP System Purge Line PerformanceLow priorityEmissions System30–120 minutes for initial diagnosisP04F1 relates to evap system purge line performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F2Catalyst Heater Supply Voltage Bank 1Check soonEmissions System30–120 minutes for initial diagnosisP04F2 relates to catalyst heater supply voltage bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F3Catalyst Heater Supply Voltage Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP04F3 relates to catalyst heater supply voltage bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F4Catalyst Heater Circuit Low Bank 1Check soonEmissions System30–120 minutes for initial diagnosisP04F4 relates to catalyst heater circuit low bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F5Catalyst Heater Circuit Low Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP04F5 relates to catalyst heater circuit low bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F6Catalyst Heater Circuit High Bank 1Check soonEmissions System30–120 minutes for initial diagnosisP04F6 relates to catalyst heater circuit high bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F7Catalyst Heater Circuit High Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP04F7 relates to catalyst heater circuit high bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F8Catalyst Heater Circuit Intermittent Bank 1Check soonEmissions System30–120 minutes for initial diagnosisP04F8 relates to catalyst heater circuit intermittent bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P04F9Catalyst Heater Circuit Intermittent Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP04F9 relates to catalyst heater circuit intermittent bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P04FAEGR A Control Temperature Too HighCheck soonEmissions System30–120 minutes for initial diagnosisP04FA relates to egr a control temperature too high. Check the fault conditions and vehicle-specific procedure before replacing parts.P04FBCrankcase Ventilation Hose Connection Sensor Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04FB relates to crankcase ventilation hose connection sensor range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P04FCCrankcase Ventilation System PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04FC relates to crankcase ventilation system performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P04FDEGR Actuator A Control Processor PerformanceCheck soonEmissions System30–120 minutes for initial diagnosisP04FD relates to egr actuator a control processor performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P04FECatalyst Heater Circuit Performance Bank 1Check soonEmissions System30–120 minutes for initial diagnosisP04FE relates to catalyst heater circuit performance bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P04FFCatalyst Heater Circuit Performance Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP04FF relates to catalyst heater circuit performance bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P0500Vehicle Speed Sensor A MalfunctionSensors & ElectronicsDiagnose P0500 vehicle speed sensor code. Learn how the VSS works and how to fix speedometer and shift issues.P0501Vehicle Speed Sensor A Range/PerformanceCheck soonSensors & Electronics45–120 minutes for initial diagnosisP0501 means Vehicle Speed Sensor A Range/Performance. Learn the likely symptoms, common causes, and a safe diagnostic order before replacing parts.