Diagnostic library

Find an OBD2 code

Search the code from your scanner, then narrow the library by system, severity, or code family.

9,253 diagnostic guides

Sort

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.

Fuel System Check soon Clear all

Quick browse

Choose a vehicle system

Engine1049 Emissions515 Fuel1016 Sensors & Electronics2110 Transmission866 Electrical & Charging1797 Body & Restraints193 Chassis & Brakes479 Network & Communication1228

FiltersSeverity · family

Severity

All severities9253 Low priority305 Check soon8256 Urgent621

Code family

All families9253 P · Powertrain7353 B · Body193 C · Chassis479 U · Network1228

Vehicle coverage

These are generic OBD2 definitions. Exact make, model, engine, and year compatibility will appear after vehicle-fitment data is added.

Diagnostic codes

Showing 817–840 of 975

Most searched first

P2A90Alternative Fuel Pump C PerformanceCheck soonFuel System30–120 minutes for initial diagnosisP2A90 relates to alternative fuel pump c performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A91Alternative Fuel Tank Select Valve A Control Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP2A91 relates to alternative fuel tank select valve a control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A92Alternative Fuel Tank Select Valve A Control PerformanceCheck soonFuel System30–120 minutes for initial diagnosisP2A92 relates to alternative fuel tank select valve a control performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A93Alternative Fuel Tank Select Valve A Control Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP2A93 relates to alternative fuel tank select valve a control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A94Alternative Fuel Tank Select Valve A Control Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP2A94 relates to alternative fuel tank select valve a control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A95Alternative Fuel Tank Select Valve B Control Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP2A95 relates to alternative fuel tank select valve b control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A96Alternative Fuel Tank Select Valve B Control Circuit PerformanceCheck soonFuel System30–120 minutes for initial diagnosisP2A96 relates to alternative fuel tank select valve b control circuit performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A97Alternative Fuel Tank Select Valve B Control Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP2A97 relates to alternative fuel tank select valve b control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A98Alternative Fuel Tank Select Valve B Control Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP2A98 relates to alternative fuel tank select valve b control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A99Alternative Fuel Tank Select Valve C Control Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP2A99 relates to alternative fuel tank select valve c control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A9AAlternative Fuel Tank Select Valve C Control Circuit PerformanceCheck soonFuel System30–120 minutes for initial diagnosisP2A9A relates to alternative fuel tank select valve c control circuit performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A9BAlternative Fuel Tank Select Valve C Control Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP2A9B relates to alternative fuel tank select valve c control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A9CAlternative Fuel Tank Select Valve C Control Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP2A9C relates to alternative fuel tank select valve c control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A9DAlternative Fuel High Pressure System Small LeakCheck soonFuel System30–120 minutes for initial diagnosisP2A9D relates to alternative fuel high pressure system small leak. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A9EAlternative Fuel Return Line Valve Control Circuit/OpenCheck soonFuel System30–120 minutes for initial diagnosisP2A9E relates to alternative fuel return line valve control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P2A9FAlternative Fuel Return Line Valve Control Circuit Range/PerformanceCheck soonFuel System30–120 minutes for initial diagnosisP2A9F relates to alternative fuel return line valve control circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2AA0Alternative Fuel Return Line Valve Control Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP2AA0 relates to alternative fuel return line valve control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2AA1Alternative Fuel Return Line Valve Control Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP2AA1 relates to alternative fuel return line valve control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2AA2Alternative Fuel Return Line Insufficient FlowCheck soonFuel System30–120 minutes for initial diagnosisP2AA2 relates to alternative fuel return line insufficient flow. Check the fault conditions and vehicle-specific procedure before replacing parts.P2AACDiesel Fuel Presence Sensor CircuitCheck soonFuel System30–120 minutes for initial diagnosisP2AAC relates to diesel fuel presence sensor circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2AADDiesel Fuel Presence Sensor Circuit Range/PerformanceCheck soonFuel System30–120 minutes for initial diagnosisP2AAD relates to diesel fuel presence sensor circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2AAEDiesel Fuel Presence Sensor Circuit LowCheck soonFuel System30–120 minutes for initial diagnosisP2AAE relates to diesel fuel presence sensor circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2AAFDiesel Fuel Presence Sensor Circuit HighCheck soonFuel System30–120 minutes for initial diagnosisP2AAF relates to diesel fuel presence sensor circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2B00Cylinder 1 Injection Pulse PerformanceCheck soonFuel System30–120 minutes for initial diagnosisP2B00 relates to cylinder 1 injection pulse performance. Check the fault conditions and vehicle-specific procedure before replacing parts.