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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.

Engine Problems 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 73–96 of 1049

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P0234Turbocharger/Supercharger A Overboost ConditionUrgentEngine Problems1–3 hours for initial diagnosisP0234 means Turbocharger/Supercharger A Overboost Condition. Learn the likely symptoms, common causes, and a safe diagnostic order before replacing parts.P023ACharge Air Cooler Coolant Pump A Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP023A relates to charge air cooler coolant pump a control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P023BCharge Air Cooler Coolant Pump A Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP023B relates to charge air cooler coolant pump a control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P023CCharge Air Cooler Coolant Pump A Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP023C relates to charge air cooler coolant pump a control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P0263Cylinder 1 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0263 relates to cylinder 1 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0266Cylinder 2 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0266 relates to cylinder 2 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0269Cylinder 3 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0269 relates to cylinder 3 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P026ECharge Air Cooler Coolant Pump A PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP026E relates to charge air cooler coolant pump a performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P026FCoolant Thermostat PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP026F relates to coolant thermostat performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0272Cylinder 4 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0272 relates to cylinder 4 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0275Cylinder 5 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0275 relates to cylinder 5 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0278Cylinder 6 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0278 relates to cylinder 6 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0281Cylinder 7 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0281 relates to cylinder 7 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0284Cylinder 8 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0284 relates to cylinder 8 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0287Cylinder 9 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0287 relates to cylinder 9 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P028ACharge Air Cooler Cooling Fan Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP028A relates to charge air cooler cooling fan control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P028BCharge Air Cooler Cooling Fan Performance/Stuck OffCheck soonEngine Problems30–120 minutes for initial diagnosisP028B relates to charge air cooler cooling fan performance/stuck off. Check the fault conditions and vehicle-specific procedure before replacing parts.P028CCharge Air Cooler Cooling Fan Stuck OnCheck soonEngine Problems30–120 minutes for initial diagnosisP028C relates to charge air cooler cooling fan stuck on. Check the fault conditions and vehicle-specific procedure before replacing parts.P028DCharge Air Cooler Cooling Fan Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP028D relates to charge air cooler cooling fan control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P028ECharge Air Cooler Cooling Fan Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP028E relates to charge air cooler cooling fan control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P028FCharge Air Cooler Cooling Fan Control Circuit Driver PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP028F relates to charge air cooler cooling fan control circuit driver performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0290Cylinder 10 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0290 relates to cylinder 10 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0293Cylinder 11 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0293 relates to cylinder 11 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.P0296Cylinder 12 Contribution/BalanceCheck soonEngine Problems30–120 minutes for initial diagnosisP0296 relates to cylinder 12 contribution/balance. Check the fault conditions and vehicle-specific procedure before replacing parts.