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 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 4729–4752 of 8256

Most searched first

P2564Turbocharger Boost Control Position Sensor A Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2564 relates to turbocharger boost control position sensor a circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2565Turbocharger Boost Control Position Sensor A Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2565 relates to turbocharger boost control position sensor a circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2566Turbocharger Boost Control Position Sensor A Circuit IntermittentCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2566 relates to turbocharger boost control position sensor a circuit intermittent. Check the fault conditions and vehicle-specific procedure before replacing parts.P2567Direct Ozone Reduction Catalyst Temperature Sensor CircuitCheck soonEmissions System30–120 minutes for initial diagnosisP2567 relates to direct ozone reduction catalyst temperature sensor circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2568Direct Ozone Reduction Catalyst Temperature Sensor Circuit Range/PerformanceCheck soonEmissions System30–120 minutes for initial diagnosisP2568 relates to direct ozone reduction catalyst temperature sensor circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2569Direct Ozone Reduction Catalyst Temperature Sensor Circuit LowCheck soonEmissions System30–120 minutes for initial diagnosisP2569 relates to direct ozone reduction catalyst temperature sensor circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P256AEngine Idle Speed Selector Sensor/Switch Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256A relates to engine idle speed selector sensor/switch circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P256BEngine Idle Speed Selector Sensor/Switch Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256B relates to engine idle speed selector sensor/switch range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P256CEngine Idle Speed Selector Sensor/Switch Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256C relates to engine idle speed selector sensor/switch circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P256DEngine Idle Speed Selector Sensor/Switch Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256D relates to engine idle speed selector sensor/switch circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P256EEngine Idle Speed Selector Sensor/Switch Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256E relates to engine idle speed selector sensor/switch circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P2570Direct Ozone Reduction Catalyst Temperature Sensor Circuit HighCheck soonEmissions System30–120 minutes for initial diagnosisP2570 relates to direct ozone reduction catalyst temperature sensor circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2571Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/ErraticCheck soonEmissions System30–120 minutes for initial diagnosisP2571 relates to direct ozone reduction catalyst temperature sensor circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P2572Direct Ozone Reduction Catalyst Deterioration Sensor CircuitCheck soonEmissions System30–120 minutes for initial diagnosisP2572 relates to direct ozone reduction catalyst deterioration sensor circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2573Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Range/PerformanceCheck soonEmissions System30–120 minutes for initial diagnosisP2573 relates to direct ozone reduction catalyst deterioration sensor circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2574Direct Ozone Reduction Catalyst Deterioration Sensor Circuit LowCheck soonEmissions System30–120 minutes for initial diagnosisP2574 relates to direct ozone reduction catalyst deterioration sensor circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2575Direct Ozone Reduction Catalyst Deterioration Sensor Circuit HighCheck soonEmissions System30–120 minutes for initial diagnosisP2575 relates to direct ozone reduction catalyst deterioration sensor circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2576Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Intermittent/ErraticCheck soonEmissions System30–120 minutes for initial diagnosisP2576 relates to direct ozone reduction catalyst deterioration sensor circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P2578Turbocharger/Supercharger Speed Sensor A CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2578 relates to turbocharger/supercharger speed sensor a circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2579Turbocharger/Supercharger Speed Sensor A Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2579 relates to turbocharger/supercharger speed sensor a circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P257AVacuum Reservoir Control Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257A relates to vacuum reservoir control circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P257BVacuum Reservoir Control Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257B relates to vacuum reservoir control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P257CVacuum Reservoir Control Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257C relates to vacuum reservoir control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P257DEngine Hood Switch Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP257D relates to engine hood switch circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.