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

• P1482 — P1482 — Additional Fan Relay Circuit Malfunction. 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, open or shorted wiring in the circuit, corroded, loose or damaged connector.
• P1483 — P1483 — Cooling Fan Driver Fault. 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, failed cooling fan or fan relay, thermostat stuck open or closed.
• P1484 — P1484 — High Fan Control Primary Circuit Malfunction. 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, poor ground connection.
• P1485 — P1485 — Fan Secondary Low with Low Fan On. 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, open or shorted wiring in the circuit, corroded, loose or damaged connector.
• P1486 — OBD2 code P1486 flags a problem with the sensor and actuator circuits (fan secondary low with high fan on). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, poor ground connection, control module driver fault.
• P1487 — OBD2 code P1487 flags a problem with the sensor and actuator circuits (SCP). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector.
• P1488 — P1488 — Exhaust Silencer Bypass Circuit Malfunction. P1488 usually does not require an immediate stop, but the exhaust silencer bypass may not operate correctly.
• P1489 — P1489 — Crankcase Ventilation Heater Control Circuit. P1489 does not normally require immediate stopping, but the underlying crankcase ventilation fault should be repaired promptly.
• P1490 — OBD2 code P1490 flags a problem with the sensor and actuator circuits (power to fan circuit overcurrent). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, open or shorted wiring in the circuit, control module driver fault.
• P1491 — P1491 — Open Power To Ground VCRM. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, open or shorted wiring in the circuit, blown fuse feeding the circuit.
• P1492 — OBD2 code P1492 flags a problem with the sensor and actuator circuits (EGRV circuit malfunction). 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.
• P1493 — OBD2 code P1493 flags a problem with the sensor and actuator circuits (EGRA circuit malfunction). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, blown fuse feeding the circuit, open or shorted wiring in the circuit.
• P1494 — OBD2 code P1494 flags a problem with the sensor and actuator circuits (EGRCHK solenoid circuit malfunction). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, open or shorted wiring in the circuit, corroded, loose or damaged connector.
• P1495 — OBD2 code P1495 flags a problem with the sensor and actuator circuits (secondary air relief solenoid circuit malfunction). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, poor ground connection, faulty sensor or actuator of the affected circuit.
• P1496 — P1496 — EGR Stepper Motor 1 Low-Signal Fault. P1496 does not usually require an immediate roadside stop, but rough running, poor power, or rising coolant temperature should be investigated promptly.
• P1498 — P1498 — EGR Stepper Motor 3 Low-Signal Fault. P1498 does not usually require immediate shutdown, but incorrect EGR operation can cause rough idle, hesitation, elevated exhaust temperature, and an emissions failure.
• P1499 — P1499 — EGR Stepper Motor 4 Low-Signal Fault. P1499 usually does not require stopping the vehicle immediately, but it should be diagnosed before long trips.
• P1501 — OBD2 code P1501 flags a problem with the sensor and actuator circuits (APLSOL solenoid circuit malfunction). 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, blown fuse feeding the circuit.
• P1503 — OBD2 code P1503 flags a problem with the sensor and actuator circuits (SPCUT solenoid circuit malfunction). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit.
• P1504 — OBD2 code P1504 flags a problem with the sensor and actuator circuits (TCSPL solenoid circuit malfunction). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, blown fuse feeding the circuit, control module driver fault.
• P1505 — Vehicle Speed Sensor Intermittent (P1505): 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, blown fuse feeding the circuit.
• P1507 — OBD2 code P1507 flags a problem with the sensor and actuator circuits (vehicle speed sensor intermittent malfunction). 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.
• P1508 — Auxillary Speed Sensor Fault (P1508): 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, control module driver fault.
• P1510 — P1510 — Idle Air Control System At Adaptive Clip. A fault in the throttle and intake air metering. Short, gentle driving to a shop is usually possible. Typical causes: wiring or connector faults in the throttle circuit, faulty throttle position sensor or pedal sensor, dirty throttle body or stuck throttle plate.