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

• P1716 — OBD2 code P1716 flags a problem with the sensor and actuator circuits (TFT sensor out of self test range). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, control module driver fault, open or shorted wiring in the circuit.
• P1717 — Trans Torque Reduction Request Signal Malfunction (P1717): 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, faulty sensor or actuator of the affected circuit, control module driver fault.
• P1719 — P1719 — Engine Torque Signal Circuit Failure. P1719 can cause the ECM to limit engine torque or command a fail-safe strategy.
• P1720 — P1720 — SSA Inductive Signature Malfunction. 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, poor ground connection, faulty sensor or actuator of the affected circuit.
• P1721 — P1721 — SSB Inductive Signature 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, blown fuse feeding the circuit, poor ground connection.
• P1723 — P1723 — SSD Inductive Signature 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, control module driver fault, corroded, loose or damaged connector.
• P1724 — OBD2 code P1724 flags a problem with the sensor and actuator circuits (TFT sensor in range failure high). 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.
• P1726 — Gear 1 Incorrect Ratio (P1726): 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, control module driver fault.
• P1728 — Gear 3 incorrect Ratio (P1728): 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, corroded, loose or damaged connector.
• P1729 — OBD2 code P1729 flags a problem with the sensor and actuator circuits (gear 4 incorrect ratio). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit, control module driver fault.
• P1730 — Insufficient Engine Speed Increase During Self Test (P1730): 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.
• P1731 — P1731 — Insufficient Engine Speed Decrease During Self Test. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: poor ground connection, blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit.
• P1732 — Coast Clutch Solenoid Inductive Signature Malfunction (P1732): 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, open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit.
• P1733 — Transmission Slip Error (P1733): 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, valve body wear, low or degraded transmission fluid.
• P1734 — P1734 — 4x4 Low Switch Error. 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.
• P1735 — OBD2 code P1735 flags a problem with the sensor and actuator circuits (gear control malfunction 2). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, corroded, loose or damaged connector, control module driver fault.
• P1736 — 1-2 Shift Malfunction (P1736): 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.
• P1737 — OBD2 code P1737 flags a problem with the sensor and actuator circuits (2-3 shift malfunction). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, control module driver fault, open or shorted wiring in the circuit.
• P1738 — P1738 — 3-4 Shift Malfunction. 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, faulty sensor or actuator of the affected circuit, poor ground connection.
• P1739 — P1739 — Gear Control Malfunction. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: poor ground connection, open or shorted wiring in the circuit, corroded, loose or damaged connector.
• P1741 — OBD2 code P1741 flags a problem with the sensor and actuator circuits (second gear switch circuit malfunction). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit.
• P1742 — Lockup Solenoid System (P1742): 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, control module driver fault, open or shorted wiring in the circuit.
• P1743 — Shift Time Error (P1743): 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, corroded, loose or damaged connector, poor ground connection.
• P1744 — P1744 — Slip Solenoid System. 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, blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit.