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.

Emissions 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 97–120 of 378

Most searched first

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.P0544Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP0544 indicates a fault related to exhaust gas temperature sensor circuit bank 1 sensor 1. Learn the likely causes and a practical diagnostic order before replacing parts.P0545Exhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP0545 relates to exhaust gas temperature sensor circuit low bank 1 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0546Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP0546 relates to exhaust gas temperature sensor circuit high bank 1 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0547Exhaust Gas Temperature Sensor Circuit Bank 2 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP0547 relates to exhaust gas temperature sensor circuit bank 2 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0548Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP0548 relates to exhaust gas temperature sensor circuit low bank 2 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0549Exhaust Gas Temperature Sensor Circuit High Bank 2 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP0549 relates to exhaust gas temperature sensor circuit high bank 2 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P055EOxygen Sensor Control Module System VoltageCheck soonEmissions System30–120 minutes for initial diagnosisP055E relates to oxygen sensor control module system voltage. Check the fault conditions and vehicle-specific procedure before replacing parts.P05EBCold Start SCR NOx Catalyst Inlet Temperature Too LowCheck soonEmissions System30–120 minutes for initial diagnosisP05EB relates to cold start scr nox catalyst inlet temperature too low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2002Particulate Filter Efficiency Below Threshold Bank 1Check soonEmissions System30–120 minutes for initial diagnosisP2002 relates to particulate filter efficiency below threshold bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2003Particulate Filter Efficiency Below Threshold Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP2003 relates to particulate filter efficiency below threshold bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2027EVAP Fuel Vapor Temperature Sensor Circuit High VoltageCheck soonEmissions System30–120 minutes for initial diagnosisP2027 relates to evap fuel vapor temperature sensor circuit high voltage. Check the fault conditions and vehicle-specific procedure before replacing parts.P2031Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosisP2031 relates to exhaust gas temperature sensor circuit bank 1 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2032Exhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosisP2032 relates to exhaust gas temperature sensor circuit low bank 1 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2033Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosisP2033 relates to exhaust gas temperature sensor circuit high bank 1 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2034Exhaust Gas Temperature Sensor Circuit Bank 2 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosisP2034 relates to exhaust gas temperature sensor circuit bank 2 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2035Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosisP2035 relates to exhaust gas temperature sensor circuit low bank 2 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2036Exhaust Gas Temperature Sensor Circuit High Bank 2 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosisP2036 relates to exhaust gas temperature sensor circuit high bank 2 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2080Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 1 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP2080 relates to exhaust gas temperature sensor circuit range/performance bank 1 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2081Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP2081 relates to exhaust gas temperature sensor circuit intermittent bank 1 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2082Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 2 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP2082 relates to exhaust gas temperature sensor circuit range/performance bank 2 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2083Exhaust Gas Temperature Sensor Circuit Intermittent Bank 2 Sensor 1Check soonEmissions System30–120 minutes for initial diagnosisP2083 relates to exhaust gas temperature sensor circuit intermittent bank 2 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2084Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 1 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosisP2084 relates to exhaust gas temperature sensor circuit range/performance bank 1 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2085Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosisP2085 relates to exhaust gas temperature sensor circuit intermittent bank 1 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.