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

• P2220 — NOx Sensor Heater Control Circuit High Bank 2 (P2220): 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 control module driver fault, poor ground connection, faulty sensor or actuator of the affected circuit.
• P2221 — P2221 — NOx Sensor Heater Sense Circuit Bank 2. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: faulty sensor or actuator of the affected circuit, poor ground connection, open or shorted wiring in the circuit.
• P2222 — P2222 — NOx Sensor Heater Sense Circuit Range/Performance Bank 2. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector, poor ground connection.
• P2223 — OBD2 code P2223 flags a problem with the sensor and actuator circuits (nox sensor heater sense circuit low bank 2). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit, poor ground connection.
• P2224 — OBD2 code P2224 flags a problem with the sensor and actuator circuits (nox sensor heater sense circuit high bank 2). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• P2225 — OBD2 code P2225 flags a problem with the sensor and actuator circuits (nox sensor heater sense circuit intermittent bank 2). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, control module driver fault, poor ground connection.
• P2226 — OBD2 code P2226 flags a problem with the sensor and actuator circuits (barometric pressure sensor "A" circuit). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• P2227 — Barometric Pressure Sensor "A" Circuit Range/Performance (P2227): 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, corroded, loose or damaged connector.
• P2228 — P2228 — Barometric Pressure Sensor "A" Circuit Low. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: poor ground connection, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P2229 — Barometric Pressure Sensor "A" Circuit High (P2229): 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 corroded, loose or damaged connector, control module driver fault, open or shorted wiring in the circuit.
• P222A — P222A — Barometric Pressure Sensor "B" Circuit. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P222B — P222B — Barometric Pressure Sensor "B" Circuit Range/Performance. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: faulty sensor or actuator of the affected circuit, control module driver fault, corroded, loose or damaged connector.
• P222C — P222C — Barometric Pressure Sensor "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.
• P222D — Barometric Pressure Sensor "B" Circuit High (P222D): 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, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• P222E — OBD2 code P222E flags a problem with the sensor and actuator circuits (barometric pressure sensor "B" circuit intermittent/erratic). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, poor ground connection, blown fuse feeding the circuit.
• P222F — P222F — Barometric Pressure Sensor "A"/"B" Correlation. 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, control module driver fault, corroded, loose or damaged connector.
• P2230 — P2230 — Barometric Pressure Sensor "A" Circuit Intermittent/Erratic. 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, faulty sensor or actuator of the affected circuit, control module driver fault.
• P2231 — O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 1 (P2231): a powertrain (engine/transmission) fault affecting the oxygen sensor circuit. The car is usually drivable while you plan the repair. Most often caused by aged or contaminated oxygen sensor, ECM signal circuit fault, damaged sensor wiring or connector.
• P2232 — O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 2 (P2232): a powertrain (engine/transmission) fault affecting the oxygen sensor circuit. The car is usually drivable while you plan the repair. Most often caused by damaged sensor wiring or connector, blown sensor heater fuse, aged or contaminated oxygen sensor.
• P2233 — P2233 — O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 3. A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: damaged sensor wiring or connector, blown sensor heater fuse, exhaust leak near the sensor.
• P2234 — P2234 — O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 2 Sensor 1. A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: exhaust leak near the sensor, damaged sensor wiring or connector, blown sensor heater fuse.
• P2235 — P2235 — O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 2 Sensor 2. A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: ECM signal circuit fault, exhaust leak near the sensor, oil or coolant contamination of the sensor tip.
• P2236 — P2236 — O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 2 Sensor 3. A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: damaged sensor wiring or connector, exhaust leak near the sensor, aged or contaminated oxygen sensor.
• P2237 — O2 Sensor Positive Current Control Circuit/Open Bank 1 Sensor 1 (P2237): a powertrain (engine/transmission) fault affecting the oxygen sensor circuit. The car is usually drivable while you plan the repair. Most often caused by blown sensor heater fuse, ECM signal circuit fault, oil or coolant contamination of the sensor tip.