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

• P0899 — OBD2 code P0899 flags a problem with the automatic transmission control (transmission control system MIL request circuit high). Short, gentle driving to a shop is usually possible. Common culprits: internal mechanical wear (clutches, torque converter), low or degraded transmission fluid, failed shift or pressure control solenoid.
• P0900 — OBD2 code P0900 flags a problem with the sensor and actuator circuits (clutch actuator circuit/open). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, corroded, loose or damaged connector, blown fuse feeding the circuit.
• P0901 — Clutch Actuator Circuit Range/Performance (P0901): 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.
• P0902 — OBD2 code P0902 flags a problem with the sensor and actuator circuits (clutch actuator circuit low). 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.
• P0903 — Clutch Actuator Circuit High (P0903): 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, faulty sensor or actuator of the affected circuit.
• P0904 — Gate Select Position Circuit (P0904): 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, faulty sensor or actuator of the affected circuit.
• P0905 — Gate Select Position Circuit Range/Performance (P0905): 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, faulty sensor or actuator of the affected circuit.
• P0906 — Gate Select Position Circuit Low (P0906): 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, blown fuse feeding the circuit.
• P0907 — Gate Select Position Circuit High (P0907): 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, corroded, loose or damaged connector, blown fuse feeding the circuit.
• P0908 — Gate Select Position Circuit Intermittent (P0908): 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, blown fuse feeding the circuit.
• P0909 — Gate Select Control Error (P0909): 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.
• P0910 — OBD2 code P0910 flags a problem with the sensor and actuator circuits (gate select actuator circuit/open). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, poor ground connection, open or shorted wiring in the circuit.
• P0911 — Gate Select Actuator Circuit Range/Performance (P0911): 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.
• P0912 — P0912 — Gate Select Actuator 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, corroded, loose or damaged connector, blown fuse feeding the circuit.
• P0913 — Gate Select Actuator Circuit High (P0913): 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, blown fuse feeding the circuit.
• P0914 — P0914 — Gear Shift Position Circuit. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: failed shift or pressure control solenoid, internal mechanical wear (clutches, torque converter), low or degraded transmission fluid.
• P0915 — Gear Shift Position Circuit Range/Performance (P0915): a powertrain (engine/transmission) fault affecting the automatic transmission control. Short, gentle driving to a shop is usually possible. Most often caused by wiring or connector faults in the valve body harness, internal mechanical wear (clutches, torque converter), low or degraded transmission fluid.
• P0916 — OBD2 code P0916 flags a problem with the automatic transmission control (gear shift position circuit low). Short, gentle driving to a shop is usually possible. Common culprits: valve body wear, internal mechanical wear (clutches, torque converter), low or degraded transmission fluid.
• P0917 — OBD2 code P0917 flags a problem with the automatic transmission control (gear shift position circuit high). Short, gentle driving to a shop is usually possible. Common culprits: faulty transmission speed sensor, failed shift or pressure control solenoid, valve body wear.
• P0918 — Gear Shift Position Circuit Intermittent (P0918): a powertrain (engine/transmission) fault affecting the automatic transmission control. Short, gentle driving to a shop is usually possible. Most often caused by faulty transmission speed sensor, failed shift or pressure control solenoid, low or degraded transmission fluid.
• P0919 — OBD2 code P0919 flags a problem with the automatic transmission control (gear shift position control error). Short, gentle driving to a shop is usually possible. Common culprits: valve body wear, low or degraded transmission fluid, faulty transmission speed sensor.
• P0920 — Gear Shift Forward Actuator Circuit/Open (P0920): a powertrain (engine/transmission) fault affecting the automatic transmission control. Short, gentle driving to a shop is usually possible. Most often caused by low or degraded transmission fluid, internal mechanical wear (clutches, torque converter), failed shift or pressure control solenoid.
• P0921 — P0921 — Gear Shift Forward Actuator Circuit Range/Performance. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: low or degraded transmission fluid, wiring or connector faults in the valve body harness, valve body wear.
• P0922 — OBD2 code P0922 flags a problem with the automatic transmission control (gear shift forward actuator circuit low). Short, gentle driving to a shop is usually possible. Common culprits: internal mechanical wear (clutches, torque converter), low or degraded transmission fluid, failed shift or pressure control solenoid.