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

• P0ACB — OBD2 code P0ACB flags a problem with the sensor and actuator circuits (hybrid battery temperature sensor "C" range/performance). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, control module driver fault, blown fuse feeding the circuit.
• P0ACC — P0ACC — Hybrid Battery Temperature Sensor "C" 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, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P0ACD — P0ACD — Hybrid Battery Temperature Sensor "C" Circuit High. 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.
• P0ACE — P0ACE — Hybrid Battery Temperature Sensor "C" Circuit Intermittent/Erratic. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, poor ground connection, corroded, loose or damaged connector.
• P0ACF — OBD2 code P0ACF flags a problem with the engine cooling and temperature control (hybrid battery pack cooling fan 3 control circuit/open). 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.
• P0AD0 — OBD2 code P0AD0 flags a problem with the engine cooling and temperature control (hybrid battery pack cooling fan 3 performance/stuck off). Short, gentle driving to a shop is usually possible. Common culprits: low coolant level or air in the system, thermostat stuck open or closed, faulty coolant temperature sensor.
• P0AD1 — OBD2 code P0AD1 flags a problem with the engine cooling and temperature control (hybrid battery pack cooling fan 3 stuck on). Short, gentle driving to a shop is usually possible. Common culprits: water pump or radiator issues, wiring faults in the sensor circuit, thermostat stuck open or closed.
• P0AD2 — P0AD2 — Hybrid Battery Pack Cooling Fan 3 Control Circuit Low. 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, faulty coolant temperature sensor.
• P0AD3 — P0AD3 — Hybrid Battery Pack Cooling Fan 3 Control 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, wiring faults in the sensor circuit, thermostat stuck open or closed.
• P0AD4 — Hybrid Battery Pack Air Flow System Insufficient Air Flow (P0AD4): 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, blown fuse feeding the circuit, poor ground connection.
• P0AD5 — Hybrid Battery Pack Air Flow Valve "A" Control Circuit/Open (P0AD5): 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, faulty sensor or actuator of the affected circuit, poor ground connection.
• P0AD6 — Range/Performance (P0AD6): 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, faulty sensor or actuator of the affected circuit, poor ground connection.
• P0AD7 — OBD2 code P0AD7 flags a problem with the sensor and actuator circuits (hybrid battery pack air flow valve "A" control circuit low). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, open or shorted wiring in the circuit, control module driver fault.
• P0AD8 — Hybrid Battery Pack Air Flow Valve "A" Control Circuit High (P0AD8): 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, poor ground connection, faulty sensor or actuator of the affected circuit.
• P0AD9 — P0AD9 — Hybrid Battery Positive Contactor Control Circuit/Open. 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.
• P0ADA — OBD2 code P0ADA flags a problem with the sensor and actuator circuits (range/performance). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, open or shorted wiring in the circuit, control module driver fault.
• P0ADB — Hybrid Battery Positive Contactor Control Circuit Low (P0ADB): 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.
• P0ADC — OBD2 code P0ADC flags a problem with the sensor and actuator circuits (hybrid battery positive contactor control circuit high). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, control module driver fault, faulty sensor or actuator of the affected circuit.
• P0ADD — OBD2 code P0ADD flags a problem with the sensor and actuator circuits (hybrid battery negative contactor control circuit/open). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, control module driver fault, corroded, loose or damaged connector.
• P0ADE — P0ADE — 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, blown fuse feeding the circuit, corroded, loose or damaged connector.
• P0ADF — P0ADF — Hybrid Battery Negative Contactor Control Circuit Low. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, poor ground connection, corroded, loose or damaged connector.
• P0AE0 — OBD2 code P0AE0 flags a problem with the sensor and actuator circuits (hybrid battery negative contactor control circuit high). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, poor ground connection, blown fuse feeding the circuit.
• P0AE1 — Hybrid Battery Precharge Contactor Circuit (P0AE1): 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, poor ground connection, open or shorted wiring in the circuit.
• P0AE2 — Hybrid Battery Precharge Contactor Circuit Stuck Closed (P0AE2): 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, faulty sensor or actuator of the affected circuit, poor ground connection.