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

• P1265 — THEFT Detected (P1265): 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.
• P1266 — P1266 — Cylinder #1 High To Low Side Short. 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, control module driver fault, poor ground connection.
• P1267 — OBD2 code P1267 flags a problem with the sensor and actuator circuits (cylinder #2 high to low side short). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• P1268 — P1268 — Cylinder #3 High To Low Side Short. 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, poor ground connection.
• P1269 — OBD2 code P1269 flags a problem with the sensor and actuator circuits (cylinder #4 high to low side short). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, control module driver fault, faulty sensor or actuator of the affected circuit.
• P1270 — OBD2 code P1270 flags a problem with the sensor and actuator circuits (cylinder #5 high to low side short). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, corroded, loose or damaged connector, blown fuse feeding the circuit.
• P1271 — P1271 — Cylinder #6 High To Low Side Short. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: poor ground connection, control module driver fault, blown fuse feeding the circuit.
• P1272 — Cylinder #7 High To Low Side Short (P1272): 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, open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit.
• P1273 — OBD2 code P1273 flags a problem with the sensor and actuator circuits (cylinder #8 high to low side short). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, corroded, loose or damaged connector, open or shorted wiring in the circuit.
• P1274 — P1274 — Immobilizer Code Not Programmed. 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, open or shorted wiring in the circuit, control module driver fault.
• P1275 — OBD2 code P1275 flags a problem with the sensor and actuator circuits (engine RPM or speed limiter reached). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, blown fuse feeding the circuit, corroded, loose or damaged connector.
• P1276 — Cylinder #1 High To Low Side Open (P1276): 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, control module driver fault, corroded, loose or damaged connector.
• P1277 — OBD2 code P1277 flags a problem with the sensor and actuator circuits (cylinder #2 high to low side open). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P1278 — Cylinder #3 High To Low Side Open (P1278): 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, faulty sensor or actuator of the affected circuit.
• P1279 — P1279 — Control Sleeve Sensor Range Fault. P1279 can be accompanied by rough idle, hesitation, or power loss.
• P1280 — P1280 — Cylinder #4 High To Low Side Open. 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, open or shorted wiring in the circuit.
• P1281 — OBD2 code P1281 flags a problem with the sensor and actuator circuits (cylinder #5 high to low side open). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P1282 — P1282 — Cylinder #6 High To Low Side 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, poor ground connection.
• P1283 — OBD2 code P1283 flags a problem with the sensor and actuator circuits (cylinder #7 high to low side open). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, corroded, loose or damaged connector, control module driver fault.
• P1284 — Cylinder #8 High To Low Side Open (P1284): 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, control module driver fault, blown fuse feeding the circuit.
• P1286 — OBD2 code P1286 flags a problem with the sensor and actuator circuits (injection control pressure out of range high). 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.
• P1287 — Excessive Injection Control Pressure (P1287): 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, blown fuse feeding the circuit, control module driver fault.
• P1288 — OBD2 code P1288 flags a problem with the sensor and actuator circuits (IPR circuit failure). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, open or shorted wiring in the circuit, blown fuse feeding the circuit.
• P1289 — Aborted KOER - ICP Failure (P1289): 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, faulty sensor or actuator of the affected circuit.