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

• P0C3F — OBD2 code P0C3F flags a problem with the sensor and actuator circuits (DC/DC converter temperature sensor "B" low). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit, control module driver fault.
• P0C40 — P0C40 — DC/DC Converter Temperature Sensor "B" High. 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, blown fuse feeding the circuit.
• P0C41 — P0C41 — DC/DC Converter Temperature Sensor "B" Intermittent/Erratic. 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, corroded, loose or damaged connector, poor ground connection.
• P0C42 — Hybrid Battery Pack Coolant Temperature Sensor Circuit (P0C42): 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 failed cooling fan or fan relay, thermostat stuck open or closed, wiring faults in the sensor circuit.
• P0C43 — Hybrid Battery Pack Coolant Temperature Sensor Circuit Range/Performance (P0C43): 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, wiring faults in the sensor circuit, failed cooling fan or fan relay.
• P0C44 — Hybrid Battery Pack Coolant Temperature Sensor Circuit Low (P0C44): 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 failed cooling fan or fan relay, wiring faults in the sensor circuit, thermostat stuck open or closed.
• P0C45 — Hybrid Battery Pack Coolant Temperature Sensor Circuit High (P0C45): 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 failed cooling fan or fan relay, low coolant level or air in the system, water pump or radiator issues.
• P0C46 — OBD2 code P0C46 flags a problem with the engine cooling and temperature control (hybrid battery pack coolant temperature sensor circuit intermittent/erratic). Short, gentle driving to a shop is usually possible. Common culprits: faulty coolant temperature sensor, water pump or radiator issues, failed cooling fan or fan relay.
• P0C47 — OBD2 code P0C47 flags a problem with the engine cooling and temperature control (hybrid battery pack coolant pump control circuit/open). Short, gentle driving to a shop is usually possible. Common culprits: wiring faults in the sensor circuit, water pump or radiator issues, low coolant level or air in the system.
• P0C48 — OBD2 code P0C48 flags a problem with the engine cooling and temperature control (hybrid battery pack coolant pump control circuit low). Short, gentle driving to a shop is usually possible. Common culprits: thermostat stuck open or closed, water pump or radiator issues, failed cooling fan or fan relay.
• P0C49 — P0C49 — Hybrid Battery Pack Coolant Pump Control Circuit High. A fault in the engine cooling and temperature control. Short, gentle driving to a shop is usually possible. Typical causes: failed cooling fan or fan relay, low coolant level or air in the system, thermostat stuck open or closed.
• P0C4A — Hybrid Battery Pack Coolant Pump Control Performance (P0C4A): 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.
• P0C4B — Hybrid Battery Pack Coolant Pump Supply Voltage Circuit/Open (P0C4B): 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 thermostat stuck open or closed, low coolant level or air in the system, faulty coolant temperature sensor.
• P0C4C — OBD2 code P0C4C flags a problem with the engine cooling and temperature control (hybrid battery pack coolant pump supply voltage circuit low). Short, gentle driving to a shop is usually possible. Common culprits: failed cooling fan or fan relay, water pump or radiator issues, thermostat stuck open or closed.
• P0C4D — P0C4D — Hybrid Battery Pack Coolant Pump Supply Voltage Circuit High. A fault in the engine cooling and temperature control. Short, gentle driving to a shop is usually possible. Typical causes: faulty coolant temperature sensor, failed cooling fan or fan relay, low coolant level or air in the system.
• P0C4E — P0C4E — Drive Motor "A" Position Exceeded Learning Limit. 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, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P0C4F — Drive Motor "B" Position Exceeded Learning Limit (P0C4F): 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, control module driver fault, corroded, loose or damaged connector.
• P0C50 — OBD2 code P0C50 flags a problem with the sensor and actuator circuits (drive motor "A" position sensor circuit "A"). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, open or shorted wiring in the circuit, corroded, loose or damaged connector.
• P0C51 — OBD2 code P0C51 flags a problem with the sensor and actuator circuits (drive motor "A" position sensor circuit "A" range/performance). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, poor ground connection, blown fuse feeding the circuit.
• P0C52 — P0C52 — Drive Motor "A" Position Sensor Circuit "A" Low. 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, poor ground connection, blown fuse feeding the circuit.
• P0C53 — Drive Motor "A" Position Sensor Circuit "A" High (P0C53): 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, open or shorted wiring in the circuit.
• P0C54 — Drive Motor "A" Position Sensor Circuit "A" Intermittent/Erratic (P0C54): 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.
• P0C56 — OBD2 code P0C56 flags a problem with the sensor and actuator circuits (drive motor "B" position sensor circuit "A" range/performance). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, poor ground connection, open or shorted wiring in the circuit.
• P0C57 — OBD2 code P0C57 flags a problem with the sensor and actuator circuits (drive motor "B" position sensor circuit "A" low). 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.