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.

Check soon P · Powertrain 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 4105–4128 of 6682

Most searched first

P242BExhaust Gas Temperature Sensor Circuit Range/Performance Bank 1 Sensor 3Check soonEmissions System30–120 minutes for initial diagnosisP242B relates to exhaust gas temperature sensor circuit range/performance bank 1 sensor 3. Check the fault conditions and vehicle-specific procedure before replacing parts.P242CExhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 3Check soonEmissions System30–120 minutes for initial diagnosisP242C relates to exhaust gas temperature sensor circuit low bank 1 sensor 3. Check the fault conditions and vehicle-specific procedure before replacing parts.P242DExhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 3Check soonEmissions System30–120 minutes for initial diagnosisP242D relates to exhaust gas temperature sensor circuit high bank 1 sensor 3. Check the fault conditions and vehicle-specific procedure before replacing parts.P242EExhaust Gas Temperature Sensor Circuit Intermittent/Erratic Bank 1 Sensor 3Check soonEmissions System30–120 minutes for initial diagnosisP242E relates to exhaust gas temperature sensor circuit intermittent/erratic bank 1 sensor 3. Check the fault conditions and vehicle-specific procedure before replacing parts.P242FParticulate Filter Restriction - Ash Accumulation Bank 1Check soonEmissions System30–120 minutes for initial diagnosisP242F relates to particulate filter restriction - ash accumulation bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2430AIR System Air Flow/Pressure Sensor Circuit Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP2430 relates to air system air flow/pressure sensor circuit bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2431AIR System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP2431 relates to air system air flow/pressure sensor circuit range/performance bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2432AIR System Air Flow/Pressure Sensor Circuit Low Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP2432 relates to air system air flow/pressure sensor circuit low bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2433AIR System Air Flow/Pressure Sensor Circuit High Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP2433 relates to air system air flow/pressure sensor circuit high bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2434AIR System Air Flow/Pressure Sensor Circuit Intermittent/Erratic Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP2434 relates to air system air flow/pressure sensor circuit intermittent/erratic bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2435AIR System Air Flow/Pressure Sensor Circuit Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP2435 relates to air system air flow/pressure sensor circuit bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2436AIR System Air Flow/Pressure Sensor Circuit Range/Performance Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP2436 relates to air system air flow/pressure sensor circuit range/performance bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2437AIR System Air Flow/Pressure Sensor Circuit Low Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP2437 relates to air system air flow/pressure sensor circuit low bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2438AIR System Air Flow/Pressure Sensor Circuit High Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP2438 relates to air system air flow/pressure sensor circuit high bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2439AIR System Air Flow/Pressure Sensor Circuit Intermittent/Erratic Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP2439 relates to air system air flow/pressure sensor circuit intermittent/erratic bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P243AParticulate Filter Restriction - Ash Accumulation Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP243A relates to particulate filter restriction - ash accumulation bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P243BParticulate Filter Restriction - Forced Limited Power Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP243B relates to particulate filter restriction - forced limited power bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P243CParticulate Filter Regeneration Frequency Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP243C relates to particulate filter regeneration frequency bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P243DParticulate Filter Regeneration Duration Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP243D relates to particulate filter regeneration duration bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P243EParticulate Filter Regeneration Incomplete Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP243E relates to particulate filter regeneration incomplete bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P243FParticulate Filter Restriction - Soot Accumulation Too High Bank 2Check soonEmissions System30–120 minutes for initial diagnosisP243F relates to particulate filter restriction - soot accumulation too high bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P2440AIR System Switching Valve Stuck Open Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP2440 relates to air system switching valve stuck open bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2441AIR System Switching Valve Stuck Closed Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP2441 relates to air system switching valve stuck closed bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P2442AIR System Switching Valve Stuck Open Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP2442 relates to air system switching valve stuck open bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.