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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 961–984 of 6682

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P04E3Crankcase Ventilation Hose Connection Sensor Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04E3 relates to crankcase ventilation hose connection sensor circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P04E4Crankcase Ventilation Hose Connection Sensor Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP04E4 relates to crankcase ventilation hose connection sensor circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P04E5EGR Temperature Sensor D CircuitCheck soonEmissions System30–120 minutes for initial diagnosisP04E5 relates to egr temperature sensor d circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P04E6EGR Temperature Sensor D Circuit Range/PerformanceCheck soonEmissions System30–120 minutes for initial diagnosisP04E6 relates to egr temperature sensor d circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P04E7EGR Temperature Sensor D Circuit LowCheck soonEmissions System30–120 minutes for initial diagnosisP04E7 relates to egr temperature sensor d circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P04E8EGR Temperature Sensor D Circuit HighCheck soonEmissions System30–120 minutes for initial diagnosisP04E8 relates to egr temperature sensor d circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P04E9EGR Temperature Sensor D Circuit Intermittent/ErraticCheck soonEmissions System30–120 minutes for initial diagnosisP04E9 relates to egr temperature sensor d circuit intermittent/erratic. 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.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.P0504Brake Switch A/B CorrelationCheck soonSensors & Electronics30–90 minutes for initial diagnosisP0504 means the brake-pedal switch signals disagree when the control module expects them to match. Learn what to check before replacing parts.P0506Idle Control System RPM Lower Than ExpectedCheck soonEngine Problems30–120 minutes for initial diagnosisP0506 indicates a fault related to idle control system rpm lower than expected. Learn the likely causes and a practical diagnostic order before replacing parts.