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.

Sensors & Electronics 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 1–24 of 2110

Most searched first

P0051Heated Oxygen Sensor Heater Control Circuit Low Bank 2 Sensor 1Low prioritySensors & Electronics45–120 minutes for initial diagnosisP0051 means Heated Oxygen Sensor Heater Control Circuit Low Bank 2 Sensor 1. Learn the likely symptoms, causes, safety implications, and a practical diagnostic order.P0057Heated Oxygen Sensor Heater Control Circuit Low Bank 2 Sensor 2Low prioritySensors & Electronics45–120 minutes for initial diagnosisP0057 means Heated Oxygen Sensor Heater Control Circuit Low Bank 2 Sensor 2. Learn the likely symptoms, causes, safety implications, and a practical diagnostic order.P0069Manifold Absolute Pressure–Barometric Pressure CorrelationCheck soonSensors & Electronics45–120 minutes for initial diagnosisP0069 means Manifold Absolute Pressure–Barometric Pressure Correlation. Learn the likely symptoms, causes, safety implications, and a practical diagnostic order.P0130O2 Sensor Circuit Malfunction Bank 1 Sensor 1Sensors & ElectronicsFix P0130 oxygen sensor code. Learn about O2 sensor locations, testing procedures, and replacement tips for Bank 1 Sensor 1.P0221Throttle/Pedal Position Sensor/Switch B Circuit Range/PerformanceCheck soonSensors & Electronics45–120 minutes for initial diagnosisP0221 means Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance. Learn the likely symptoms, causes, safety implications, and a practical diagnostic order.P0235Turbocharger/Supercharger Boost Sensor A CircuitCheck soonSensors & Electronics45–120 minutes for initial diagnosisP0235 means Turbocharger/Supercharger Boost Sensor A Circuit. Learn the likely symptoms, causes, safety implications, and a practical diagnostic order.P0335Crankshaft Position Sensor Circuit MalfunctionSensors & ElectronicsDiagnose P0335 crank sensor code. Learn about the crankshaft position sensor and no-start conditions.P0340Camshaft Position Sensor Circuit MalfunctionSensors & ElectronicsFix P0340 camshaft sensor code. Learn about cam position sensor function and replacement.P0008Engine Position System Performance Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP0008 relates to engine position system performance bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0009Engine Position System Performance Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP0009 relates to engine position system performance bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P0026Intake Valve Control Solenoid Circuit Range/Performance Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP0026 relates to intake valve control solenoid circuit range/performance bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0027Exhaust Valve Control Solenoid Circuit Range/Performance Bank 1Check soonSensors & Electronics30–120 minutes for initial diagnosisP0027 relates to exhaust valve control solenoid circuit range/performance bank 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0028Intake Valve Control Solenoid Circuit Range/Performance Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP0028 relates to intake valve control solenoid circuit range/performance bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P0029Exhaust Valve Control Solenoid Circuit Range/Performance Bank 2Check soonSensors & Electronics30–120 minutes for initial diagnosisP0029 relates to exhaust valve control solenoid circuit range/performance bank 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P0030HO2S Heater Control Circuit Bank 1 Sensor 1Low prioritySensors & Electronics30–120 minutes for initial diagnosisP0030 relates to ho2s heater control circuit bank 1 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0031HO2S Heater Control Circuit Low Bank 1 Sensor 1Low prioritySensors & Electronics30–120 minutes for initial diagnosisP0031 relates to ho2s heater control circuit low bank 1 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0032HO2S Heater Control Circuit High Bank 1 Sensor 1Low prioritySensors & Electronics30–120 minutes for initial diagnosisP0032 relates to ho2s heater control circuit high bank 1 sensor 1. Check the fault conditions and vehicle-specific procedure before replacing parts.P0033Turbocharger/Supercharger Bypass Valve A Control CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0033 relates to turbocharger/supercharger bypass valve a control circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P0034Turbocharger/Supercharger Bypass Valve A Control Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0034 relates to turbocharger/supercharger bypass valve a control circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P0035Turbocharger/Supercharger Bypass Valve A Control Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0035 relates to turbocharger/supercharger bypass valve a control circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P0036HO2S Heater Control Circuit Bank 1 Sensor 2Low prioritySensors & Electronics30–120 minutes for initial diagnosisP0036 relates to ho2s heater control circuit bank 1 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P0037HO2S Heater Control Circuit Low Bank 1 Sensor 2Low prioritySensors & Electronics30–120 minutes for initial diagnosisP0037 relates to ho2s heater control circuit low bank 1 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P0038HO2S Heater Control Circuit High Bank 1 Sensor 2Low prioritySensors & Electronics30–120 minutes for initial diagnosisP0038 relates to ho2s heater control circuit high bank 1 sensor 2. Check the fault conditions and vehicle-specific procedure before replacing parts.P0039Turbocharger/Supercharger Bypass Valve A Control Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP0039 relates to turbocharger/supercharger bypass valve a control circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.