OBD2 Fault Code Library

Free lookup for thousands of OBD2 trouble codes: filter by family, read short meanings, and open deeper articles. Desktop ELM327 scanner with live data and AI guidance.

OBD2 symptoms

Look up diagnostic trouble codes by what the car is doing: misfire, overheating, rough idle, a check engine light, and other common symptoms.

• Engine misfire
• Engine overheating
• Rough idle
• Check engine light
• Poor fuel economy
• Hard starting
• Engine stalling
• Catalytic converter efficiency
• Oxygen sensor fault
• EVAP leak
• Thermostat not reaching temperature
• Lean air-fuel mixture
• Rich air-fuel mixture
• EGR flow fault
• Engine knock
• Charging system
• Throttle position
• Mass airflow sensor
• Turbo underboost
• Coolant temperature sensor
• Transmission fault

• P0109 — OBD2 code P0109 flags a problem with the throttle and intake air metering (manifold absolute pressure/barometric pressure circuit intermittent). Short, gentle driving to a shop is usually possible. Common culprits: contaminated or failed MAF/MAP sensor, wiring or connector faults in the throttle circuit, dirty throttle body or stuck throttle plate.
• P010A — Mass or Volume Air Flow "B" Circuit (P010A): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by blown fuse feeding the circuit, open or shorted wiring in the circuit, poor ground connection.
• P010B — Mass or Volume Air Flow "B" Circuit Range/Performance (P010B): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by poor ground connection, blown fuse feeding the circuit, corroded, loose or damaged connector.
• P010C — P010C — Mass or Volume Air Flow "B" Circuit Low. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: corroded, loose or damaged connector, control module driver fault, blown fuse feeding the circuit.
• P010D — P010D — Mass or Volume Air Flow "B" Circuit High. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: blown fuse feeding the circuit, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P010E — OBD2 code P010E flags a problem with the sensor and actuator circuits (mass or volume air flow "B" circuit intermittent/erratic). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P010F — Mass or Volume Air Flow Sensor A/B Correlation (P010F): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector, poor ground connection.
• P0110 — OBD2 code P0110 flags a problem with the throttle and intake air metering (intake air temperature circuit malfunction bank 1). Short, gentle driving to a shop is usually possible. Common culprits: dirty throttle body or stuck throttle plate, wiring or connector faults in the throttle circuit, contaminated or failed MAF/MAP sensor.
• P0111 — Intake Air Temperature Circuit Range/Performance Problem Bank 1 (P0111): a powertrain (engine/transmission) fault affecting the throttle and intake air metering. Short, gentle driving to a shop is usually possible. Most often caused by contaminated or failed MAF/MAP sensor, wiring or connector faults in the throttle circuit, dirty throttle body or stuck throttle plate.
• P0112 — OBD2 code P0112 flags a problem with the throttle and intake air metering (intake air temperature circuit low input bank 1). Short, gentle driving to a shop is usually possible. Common culprits: intake air leaks after the MAF sensor, failed electronic throttle motor, contaminated or failed MAF/MAP sensor.
• P0113 — Intake Air Temperature Circuit High Input Bank 1 (P0113): a powertrain (engine/transmission) fault affecting the throttle and intake air metering. Short, gentle driving to a shop is usually possible. Most often caused by intake air leaks after the MAF sensor, failed electronic throttle motor, faulty throttle position sensor or pedal sensor.
• P0114 — OBD2 code P0114 flags a problem with the throttle and intake air metering (intake air temperature circuit intermittent bank 1). Short, gentle driving to a shop is usually possible. Common culprits: faulty throttle position sensor or pedal sensor, contaminated or failed MAF/MAP sensor, dirty throttle body or stuck throttle plate.
• P0115 — OBD2 code P0115 flags a problem with the engine cooling and temperature control (engine coolant temperature sensor circuit 1 malfunction). Short, gentle driving to a shop is usually possible. Common culprits: low coolant level or air in the system, faulty coolant temperature sensor, thermostat stuck open or closed.
• P0116 — OBD2 code P0116 flags a problem with the engine cooling and temperature control (engine coolant temperature sensor circuit 1 range/performance problem). Short, gentle driving to a shop is usually possible. Common culprits: water pump or radiator issues, faulty coolant temperature sensor, failed cooling fan or fan relay.
• P0117 — P0117 — Engine Coolant Temperature Sensor Circuit 1 Low Input. A fault in the engine cooling and temperature control. Short, gentle driving to a shop is usually possible. Typical causes: low coolant level or air in the system, failed cooling fan or fan relay, water pump or radiator issues.
• P0118 — Engine Coolant Temperature Sensor Circuit 1 High Input (P0118): a powertrain (engine/transmission) fault affecting the engine cooling and temperature control. Short, gentle driving to a shop is usually possible. Most often caused by water pump or radiator issues, failed cooling fan or fan relay, faulty coolant temperature sensor.
• P0119 — P0119 — Engine Coolant Temperature Sensor Circuit 1 Intermittent. A fault in the engine cooling and temperature control. Short, gentle driving to a shop is usually possible. Typical causes: low coolant level or air in the system, thermostat stuck open or closed, failed cooling fan or fan relay.
• P011A — P011A — Engine Coolant Temperature Sensor 1/2 Correlation. A fault in the engine cooling and temperature control. Short, gentle driving to a shop is usually possible. Typical causes: water pump or radiator issues, wiring faults in the sensor circuit, thermostat stuck open or closed.
• P011B — OBD2 code P011B flags a problem with the engine cooling and temperature control (engine coolant temperature/intake air temperature correlation). Short, gentle driving to a shop is usually possible. Common culprits: faulty coolant temperature sensor, water pump or radiator issues, thermostat stuck open or closed.
• P011C — P011C — Charge Air Temperature/Intake Air Temperature Correlation Bank 1. A fault in the throttle and intake air metering. Short, gentle driving to a shop is usually possible. Typical causes: wiring or connector faults in the throttle circuit, intake air leaks after the MAF sensor, dirty throttle body or stuck throttle plate.
• P011D — P011D — Charge Air Temperature/Intake Air Temperature Correlation Bank 2. A fault in the throttle and intake air metering. Short, gentle driving to a shop is usually possible. Typical causes: wiring or connector faults in the throttle circuit, contaminated or failed MAF/MAP sensor, dirty throttle body or stuck throttle plate.
• P0120 — Throttle Position Sensor/Switch A Circuit Malfunction (P0120): a powertrain (engine/transmission) fault affecting the throttle and intake air metering. Short, gentle driving to a shop is usually possible. Most often caused by dirty throttle body or stuck throttle plate, contaminated or failed MAF/MAP sensor, intake air leaks after the MAF sensor.
• P0121 — P0121 — Throttle Position Sensor/Switch A Circuit Range/Performance Problem. A fault in the throttle and intake air metering. Short, gentle driving to a shop is usually possible. Typical causes: contaminated or failed MAF/MAP sensor, intake air leaks after the MAF sensor, dirty throttle body or stuck throttle plate.
• P0122 — P0122 — Throttle Position Sensor/Switch A Circuit Low Input. A fault in the throttle and intake air metering. Short, gentle driving to a shop is usually possible. Typical causes: failed electronic throttle motor, dirty throttle body or stuck throttle plate, contaminated or failed MAF/MAP sensor.