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
- P0551 — Power Steering Pressure Sensor Circuit Range/Performance (P0551): 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, blown fuse feeding the circuit, open or shorted wiring in the circuit.
- P0552 — OBD2 code P0552 flags a problem with the sensor and actuator circuits (power steering pressure sensor circuit low input). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, poor ground connection, corroded, loose or damaged connector.
- P0553 — OBD2 code P0553 flags a problem with the sensor and actuator circuits (power steering pressure sensor circuit high input). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, poor ground connection, open or shorted wiring in the circuit.
- P0554 — OBD2 code P0554 flags a problem with the sensor and actuator circuits (power steering pressure sensor circuit intermittent). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit.
- P0555 — OBD2 code P0555 flags a problem with the turbocharger / supercharger boost control (brake booster pressure sensor circuit). Short, gentle driving to a shop is usually possible. Common culprits: boost leak in intercooler piping or hoses, vacuum or actuator line damage, clogged intake or exhaust (DPF/cat).
- P0556 — OBD2 code P0556 flags a problem with the turbocharger / supercharger boost control (brake booster pressure sensor circuit range/performance). Short, gentle driving to a shop is usually possible. Common culprits: vacuum or actuator line damage, worn turbocharger, clogged intake or exhaust (DPF/cat).
- P0557 — P0557 — Brake Booster Pressure Sensor Circuit Low. A fault in the turbocharger / supercharger boost control. Short, gentle driving to a shop is usually possible. Typical causes: boost leak in intercooler piping or hoses, worn turbocharger, vacuum or actuator line damage.
- P0558 — OBD2 code P0558 flags a problem with the turbocharger / supercharger boost control (brake booster pressure sensor circuit high). Short, gentle driving to a shop is usually possible. Common culprits: boost leak in intercooler piping or hoses, clogged intake or exhaust (DPF/cat), worn turbocharger.
- P0559 — P0559 — Brake Booster Pressure Sensor Circuit Intermittent. A fault in the turbocharger / supercharger boost control. Short, gentle driving to a shop is usually possible. Typical causes: boost leak in intercooler piping or hoses, vacuum or actuator line damage, worn turbocharger.
- P0560 — System Voltage Malfunction (P0560): 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, open or shorted wiring in the circuit, corroded, loose or damaged connector.
- P0561 — System Voltage Unstable (P0561): 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, open or shorted wiring in the circuit, poor ground connection.
- P0562 — P0562 — System Voltage Low. 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, poor ground connection.
- P0563 — P0563 — System Voltage High. 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.
- P0564 — OBD2 code P0564 flags a problem with the sensor and actuator circuits (cruise control multi-function input "A" circuit). 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, control module driver fault.
- P0565 — Cruise Control On Signal Malfunction (P0565): 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, open or shorted wiring in the circuit, blown fuse feeding the circuit.
- P0566 — Cruise Control Off Signal Malfunction (P0566): 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, poor ground connection.
- P0567 — OBD2 code P0567 flags a problem with the sensor and actuator circuits (cruise control resume signal malfunction). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, poor ground connection, corroded, loose or damaged connector.
- P0568 — Cruise Control Set Signal Malfunction (P0568): 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.
- P0569 — P0569 — Cruise Control Coast Signal Malfunction. 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, faulty sensor or actuator of the affected circuit.
- P056A — Cruise Control "Increase Distance" Signal (P056A): 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, blown fuse feeding the circuit.
- P056B — OBD2 code P056B flags a problem with the sensor and actuator circuits (cruise control "decrease distance" signal). 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, poor ground connection.
- P0570 — Cruise Control Accel Signal Malfunction (P0570): 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, poor ground connection, corroded, loose or damaged connector.
- P0571 — P0571 — Cruise Control/Brake Switch A Circuit Malfunction. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: damaged tone (reluctor) ring on the hub, blown fuse or low voltage to the ABS module, faulty ABS module or pump motor.
- P0572 — OBD2 code P0572 flags a problem with the ABS / stability control (cruise control/brake switch a circuit low). Short, gentle driving to a shop is usually possible. Common culprits: blown fuse or low voltage to the ABS module, damaged tone (reluctor) ring on the hub, damaged sensor wiring or corroded connector.