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

• P0A39 — OBD2 code P0A39 flags a problem with the sensor and actuator circuits (generator temperature sensor circuit high). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector, open or shorted wiring in the circuit.
• P0A3A — OBD2 code P0A3A flags a problem with the sensor and actuator circuits (generator temperature sensor circuit intermittent). 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, poor ground connection.
• P0A3B — OBD2 code P0A3B flags a problem with the sensor and actuator circuits (generator over temperature). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, open or shorted wiring in the circuit, blown fuse feeding the circuit.
• P0A3C — Drive Motor "A" Inverter Over Temperature (P0A3C): 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 open or shorted wiring in the circuit, corroded, loose or damaged connector, blown fuse feeding the circuit.
• P0A3D — Drive Motor "B" Inverter Over Temperature (P0A3D): 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 open or shorted wiring in the circuit, control module driver fault, corroded, loose or damaged connector.
• P0A3E — OBD2 code P0A3E flags a problem with the sensor and actuator circuits (generator inverter over temperature). 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.
• P0A3F — Drive Motor "A" Position Sensor Circuit (P0A3F): 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, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• P0A40 — Drive Motor "A" Position Sensor Circuit Range/Performance (P0A40): 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, open or shorted wiring in the circuit, poor ground connection.
• P0A41 — OBD2 code P0A41 flags a problem with the sensor and actuator circuits (drive motor "A" position sensor circuit low). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, open or shorted wiring in the circuit, poor ground connection.
• P0A42 — P0A42 — Drive Motor "A" Position Sensor Circuit High. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, open or shorted wiring in the circuit, poor ground connection.
• P0A43 — Drive Motor "A" Position Sensor Circuit Intermittent (P0A43): 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, blown fuse feeding the circuit.
• P0A44 — P0A44 — Drive Motor "A" Position Sensor Circuit Overspeed. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit, poor ground connection.
• P0A45 — Drive Motor "B" Position Sensor Circuit (P0A45): 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 open or shorted wiring in the circuit, control module driver fault, poor ground connection.
• P0A46 — OBD2 code P0A46 flags a problem with the sensor and actuator circuits (drive motor "B" position sensor circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, poor ground connection, control module driver fault.
• P0A47 — P0A47 — Drive Motor "B" Position Sensor 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, open or shorted wiring in the circuit, control module driver fault.
• P0A48 — Drive Motor "B" Position Sensor Circuit High (P0A48): 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, open or shorted wiring in the circuit, control module driver fault.
• P0A49 — OBD2 code P0A49 flags a problem with the sensor and actuator circuits (drive motor "B" position sensor circuit intermittent). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit, poor ground connection.
• P0A4A — OBD2 code P0A4A flags a problem with the sensor and actuator circuits (drive motor "B" position sensor circuit overspeed). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, blown fuse feeding the circuit, control module driver fault.
• P0A4B — P0A4B — Generator Position Sensor 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, faulty sensor or actuator of the affected circuit, poor ground connection.
• P0A4C — Generator Position Sensor Circuit Range/Performance (P0A4C): 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, blown fuse feeding the circuit, corroded, loose or damaged connector.
• P0A4D — P0A4D — Generator Position Sensor Circuit Low. 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, open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit.
• P0A4E — Generator Position Sensor Circuit High (P0A4E): 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 open or shorted wiring in the circuit, corroded, loose or damaged connector, poor ground connection.
• P0A4F — OBD2 code P0A4F flags a problem with the sensor and actuator circuits (generator position sensor circuit intermittent). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, open or shorted wiring in the circuit, control module driver fault.
• P0A50 — OBD2 code P0A50 flags a problem with the sensor and actuator circuits (generator position sensor circuit overspeed). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit.