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.

P3485 — P3485 — Cylinder 11 Exhaust Valve Control Circuit/Open. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector.
P3486 — OBD2 code P3486 flags a problem with the sensor and actuator circuits (cylinder 11 exhaust valve control circuit performance). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit.
P3487 — Cylinder 11 Exhaust Valve Control Circuit Low (P3487): 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, poor ground connection, blown fuse feeding the circuit.
P3488 — Cylinder 11 Exhaust Valve Control Circuit High (P3488): 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, corroded, loose or damaged connector.
P3489 — OBD2 code P3489 flags a problem with the sensor and actuator circuits (cylinder 12 deactivation/intake valve control circuit/open). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, faulty sensor or actuator of the affected circuit, poor ground connection.
P3490 — Cylinder 12 Deactivation/Intake Valve Control Circuit Performance (P3490): 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, corroded, loose or damaged connector, control module driver fault.
P3491 — OBD2 code P3491 flags a problem with the sensor and actuator circuits (cylinder 12 deactivation/intake valve control circuit low). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, blown fuse feeding the circuit, open or shorted wiring in the circuit.
P3492 — P3492 — Cylinder 12 Deactivation/Intake Valve Control 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, control module driver fault, blown fuse feeding the circuit.
P3493 — Cylinder 12 Exhaust Valve Control Circuit/Open (P3493): 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.
P3494 — P3494 — Cylinder 12 Exhaust Valve Control Circuit Performance. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, faulty sensor or actuator of the affected circuit, blown fuse feeding the circuit.
P3495 — P3495 — Cylinder 12 Exhaust Valve Control Circuit 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, corroded, loose or damaged connector, control module driver fault.
P3497 — OBD2 code P3497 flags a problem with the sensor and actuator circuits (cylinder deactivation system bank 2). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, control module driver fault, faulty sensor or actuator of the affected circuit.
U0003 — U0003 — High Speed CAN Communication Bus (+) Open. A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: corroded connectors, especially in wet areas, water ingress in harness junctions, a faulty module pulling the bus down.
U0004 — High Speed CAN Communication Bus (+) Low (U0004): a vehicle network fault affecting the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Most often caused by water ingress in harness junctions, aftermarket equipment interfering with the bus, a faulty module pulling the bus down.
U0005 — U0005 — High Speed CAN Communication Bus (+) High. A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: a faulty module pulling the bus down, aftermarket equipment interfering with the bus, water ingress in harness junctions.
U0006 — OBD2 code U0006 flags a problem with the vehicle network (CAN bus) communication (high speed CAN communication bus (-) open). Short, gentle driving to a shop is usually possible. Common culprits: poor grounds or low battery voltage, water ingress in harness junctions, aftermarket equipment interfering with the bus.
U0007 — U0007 — High Speed CAN Communication Bus (-) Low. A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: a faulty module pulling the bus down, water ingress in harness junctions, poor grounds or low battery voltage.
U0009 — High Speed CAN Communication Bus (-) shorted to Bus (+) (U0009): a vehicle network fault affecting the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Most often caused by a faulty module pulling the bus down, poor grounds or low battery voltage, damaged CAN bus wiring or short to power/ground.
U0010 — U0010 — Medium Speed CAN Communication Bus. A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: corroded connectors, especially in wet areas, poor grounds or low battery voltage, aftermarket equipment interfering with the bus.
U0011 — U0011 — Medium Speed CAN Communication Bus Performance. A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: water ingress in harness junctions, corroded connectors, especially in wet areas, damaged CAN bus wiring or short to power/ground.
U0012 — OBD2 code U0012 flags a problem with the vehicle network (CAN bus) communication (medium speed CAN communication bus (+) open). Short, gentle driving to a shop is usually possible. Common culprits: water ingress in harness junctions, poor grounds or low battery voltage, corroded connectors, especially in wet areas.
U0013 — OBD2 code U0013 flags a problem with the vehicle network (CAN bus) communication (medium speed CAN communication bus (+) low). Short, gentle driving to a shop is usually possible. Common culprits: damaged CAN bus wiring or short to power/ground, water ingress in harness junctions, poor grounds or low battery voltage.
U0014 — Medium Speed CAN Communication Bus (+) High (U0014): a vehicle network fault affecting the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Most often caused by a faulty module pulling the bus down, corroded connectors, especially in wet areas, poor grounds or low battery voltage.
U0015 — OBD2 code U0015 flags a problem with the vehicle network (CAN bus) communication (medium speed CAN communication bus (-) open). Short, gentle driving to a shop is usually possible. Common culprits: poor grounds or low battery voltage, corroded connectors, especially in wet areas, water ingress in harness junctions.