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.

Engine Problems 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 505–528 of 987

Most searched first

P26BAEngine Coolant Bypass Valve C Stuck/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP26BA relates to engine coolant bypass valve c stuck/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P26BBEngine Coolant Bypass Valve C Range/PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP26BB relates to engine coolant bypass valve c range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P26BCEngine Coolant Bypass Valve C Stuck ClosedCheck soonEngine Problems30–120 minutes for initial diagnosisP26BC relates to engine coolant bypass valve c stuck closed. Check the fault conditions and vehicle-specific procedure before replacing parts.P26BDEngine Coolant Bypass Valve D Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP26BD relates to engine coolant bypass valve d control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P26BEEngine Coolant Bypass Valve D Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP26BE relates to engine coolant bypass valve d control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P26BFEngine Coolant Bypass Valve D Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP26BF relates to engine coolant bypass valve d control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P26C0Engine Coolant Bypass Valve D Stuck/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP26C0 relates to engine coolant bypass valve d stuck/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P26C1Engine Coolant Bypass Valve D Range/PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP26C1 relates to engine coolant bypass valve d range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P26C2Engine Coolant Bypass Valve D Stuck ClosedCheck soonEngine Problems30–120 minutes for initial diagnosisP26C2 relates to engine coolant bypass valve d stuck closed. Check the fault conditions and vehicle-specific procedure before replacing parts.P26CAEngine Coolant Pump Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP26CA relates to engine coolant pump control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P26CBEngine Coolant Pump Performance/Stuck OffCheck soonEngine Problems30–120 minutes for initial diagnosisP26CB relates to engine coolant pump performance/stuck off. Check the fault conditions and vehicle-specific procedure before replacing parts.P26CCEngine Coolant Pump Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP26CC relates to engine coolant pump control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P26CDEngine Coolant Pump Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP26CD relates to engine coolant pump control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P26F4Coolant Pump C Control Circuit/OpenCheck soonEngine Problems30–120 minutes for initial diagnosisP26F4 relates to coolant pump c control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P26F5Coolant Pump C Control Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP26F5 relates to coolant pump c control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P26F6Coolant Pump C Control Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP26F6 relates to coolant pump c control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P26F8Coolant Pump C Stuck/StalledCheck soonEngine Problems30–120 minutes for initial diagnosisP26F8 relates to coolant pump c stuck/stalled. Check the fault conditions and vehicle-specific procedure before replacing parts.P26F9Coolant Pump C Control Module OvertemperatureCheck soonEngine Problems30–120 minutes for initial diagnosisP26F9 relates to coolant pump c control module overtemperature. Check the fault conditions and vehicle-specific procedure before replacing parts.P2890Cylinder 1 Ion Current Sense CircuitCheck soonEngine Problems30–120 minutes for initial diagnosisP2890 relates to cylinder 1 ion current sense circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2891Cylinder 1 Ion Current Sense Circuit Range/PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP2891 relates to cylinder 1 ion current sense circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2892Cylinder 1 Ion Current Sense Circuit LowCheck soonEngine Problems30–120 minutes for initial diagnosisP2892 relates to cylinder 1 ion current sense circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2893Cylinder 1 Ion Current Sense Circuit HighCheck soonEngine Problems30–120 minutes for initial diagnosisP2893 relates to cylinder 1 ion current sense circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2894Cylinder 2 Ion Current Sense CircuitCheck soonEngine Problems30–120 minutes for initial diagnosisP2894 relates to cylinder 2 ion current sense circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2895Cylinder 2 Ion Current Sense Circuit Range/PerformanceCheck soonEngine Problems30–120 minutes for initial diagnosisP2895 relates to cylinder 2 ion current sense circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.