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

• C0665 — C0665 — C0665 — Left Rear Wheel Speed Sensor B Incorrect Component Installed: Causes, Symptoms & Fix. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: faulty ABS module or pump motor, damaged sensor wiring or corroded connector, damaged tone (reluctor) ring on the hub.
• C0666 — C0666 — C0666 — Right Rear Wheel Speed Sensor B Circuit/Open: Causes, Symptoms & Fix. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: failed wheel speed sensor, damaged sensor wiring or corroded connector, damaged tone (reluctor) ring on the hub.
• C0667 — OBD2 code C0667 flags a problem with the ABS / stability control (C0667 — right rear wheel speed sensor b range/performance: causes, symptoms & fix). 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.
• C0668 — OBD2 code C0668 flags a problem with the ABS / stability control (C0668 — right rear wheel speed sensor b circuit low: causes, symptoms & fix). Short, gentle driving to a shop is usually possible. Common culprits: faulty ABS module or pump motor, damaged tone (reluctor) ring on the hub, blown fuse or low voltage to the ABS module.
• C0669 — OBD2 code C0669 flags a problem with the ABS / stability control (C0669 — right rear wheel speed sensor b circuit high: causes, symptoms & fix). Short, gentle driving to a shop is usually possible. Common culprits: damaged sensor wiring or corroded connector, faulty ABS module or pump motor, failed wheel speed sensor.
• C066A — C066A — C066A — Right Rear Wheel Speed Sensor B Intermittent/Erratic: Causes, Symptoms & Fix. 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, faulty ABS module or pump motor, blown fuse or low voltage to the ABS module.
• C066B — C066B — C066B — Right Rear Wheel Speed Sensor B Correlation: Causes, Symptoms & Fix. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: damaged sensor wiring or corroded connector, failed wheel speed sensor, damaged tone (reluctor) ring on the hub.
• C066C — C066C — Right Rear Wheel Speed Sensor B Incorrect Component Installed: Causes, Symptoms & Fix (C066C): a vehicle fault affecting the ABS / stability control. Short, gentle driving to a shop is usually possible. Most often caused by faulty ABS module or pump motor, blown fuse or low voltage to the ABS module, damaged sensor wiring or corroded connector.
• C066D — OBD2 code C066D flags a problem with the ABS / stability control (C066D — service/park brake chamber pressure sensor: causes, symptoms & fix). Short, gentle driving to a shop is usually possible. Common culprits: failed wheel speed sensor, faulty ABS module or pump motor, damaged sensor wiring or corroded connector.
• C066E — C066E — C066E — Service/Park Brake Chamber Pressure Too High: Causes, Symptoms & Fix. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: damaged sensor wiring or corroded connector, damaged tone (reluctor) ring on the hub, blown fuse or low voltage to the ABS module.
• C066F — OBD2 code C066F flags a problem with the ABS / stability control (C066F — service/park brake chamber pressure too low: causes, symptoms & fix). Short, gentle driving to a shop is usually possible. Common culprits: blown fuse or low voltage to the ABS module, faulty ABS module or pump motor, failed wheel speed sensor.
• C0869 — C0869 — C0869 — Air Suspension Auxiliary Inflator Indicator Lamp Circuit Failure: Causes, Symptoms & Fix. 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, blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit.
• C1001 — C1001 — C1001 — Vision System Camera: Causes, Symptoms & Fix. 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, open or shorted wiring in the circuit.
• C1002 — C1002 — C1002 — Left Power Running Board Stow: Causes, Symptoms & Fix. 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, open or shorted wiring in the circuit.
• C1003 — OBD2 code C1003 flags a problem with the sensor and actuator circuits (C1003 — right power running board stow: causes, symptoms & fix). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, control module driver fault, corroded, loose or damaged connector.
• C1004 — C1004 — Right Power Running Board Deploy: Causes, Symptoms & Fix (C1004): a vehicle 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, control module driver fault.
• C1005 — C1005 — Left Power Running Board Deploy: Causes, Symptoms & Fix (C1005): a vehicle fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by poor ground connection, corroded, loose or damaged connector, control module driver fault.
• C1006 — OBD2 code C1006 flags a problem with the sensor and actuator circuits (C1006 — left power running board motor: causes, symptoms & fix). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, poor ground connection, faulty sensor or actuator of the affected circuit.
• C1007 — C1007 — Right Power Running Board Motor: Causes, Symptoms & Fix (C1007): a vehicle 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, faulty sensor or actuator of the affected circuit.
• C1008 — C1008 — C1008 — Left Power Running Board Position/Motion Sensor: Causes, Symptoms & Fix. 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, control module driver fault, poor ground connection.
• C1009 — C1009 — Right Power Running Board Position/Motion Sensor: Causes, Symptoms & Fix (C1009): a vehicle fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by poor ground connection, corroded, loose or damaged connector, control module driver fault.
• C100A — C100A — Brake Pedal Angle Sensor: Causes, Symptoms & Fix (C100A): a vehicle fault affecting the ABS / stability control. Short, gentle driving to a shop is usually possible. Most often caused by damaged tone (reluctor) ring on the hub, failed wheel speed sensor, blown fuse or low voltage to the ABS module.
• C100B — OBD2 code C100B flags a problem with the sensor and actuator circuits (C100B — motor drive current: causes, symptoms & fix). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, blown fuse feeding the circuit, poor ground connection.
• C100C — C100C — C100C — Steering Tracking: Causes, Symptoms & Fix. 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.