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

• P1160 — P1160 — Bank 2 Sensor 2 Heater Performance. P1160 may allow continued driving without major damage, but incorrect oxygen-sensor heating can affect fuel economy, emissions, and engine stability.
• P1161 — P1161 — Bank 1 Sensor 1 Oxygen Fault. P1161 commonly affects emissions and fuel metering rather than immediate safety, but persistent lean operation can damage components or increase fuel use.
• P1162 — P1162 — Bank 1 Sensor 1 Oxygen Fault. P1162 is generally not an immediate stop condition, but continued operation can increase fuel consumption and emissions or contribute to unstable operation.
• P1163 — P1163 — Bank 2 Sensor 1 Oxygen Fault. P1163 does not usually require immediate stopping, but sustained incorrect fueling can damage the catalytic converter.
• P1164 — P1164 — Bank 2 Sensor 1 Oxygen Malfunction. P1164 is usually drivable if the engine runs smoothly, but fuel economy and emissions may be affected.
• P1165 — P1165 — Bank 1 Sensor 1 Low-Fuel Oxygen Fault. The vehicle may be drivable with a properly filled tank, but P1165 can recur when fuel is low and may accompany inaccurate mixture control.
• P1166 — P1166 — Low-Fuel Bank 2 Sensor 1 Oxygen Fault. If P1166 is the only code and the engine runs normally, driving cautiously is generally possible while avoiding prolonged low-fuel operation.
• P1167 — P1167 — Alternative Fuel Controller. 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, poor ground connection, control module driver fault.
• P1168 — P1168 — Fuel Select Switch 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, corroded, loose or damaged connector, poor ground connection.
• P1169 — OBD2 code P1169 flags a problem with the oxygen sensor circuit (lack of HO2S22 switch - sensor indicates lean). The car is usually drivable while you plan the repair. Common culprits: blown sensor heater fuse, oil or coolant contamination of the sensor tip, damaged sensor wiring or connector.
• P1170 — P1170 — Lack Of HO2S22 Switch - Sensor Indicates Rich. A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: blown sensor heater fuse, oil or coolant contamination of the sensor tip, damaged sensor wiring or connector.
• P1171 — P1171 — Fuel Stepper Motor 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, poor ground connection, open or shorted wiring in the circuit.
• P1172 — Invalid Test (P1172): 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, corroded, loose or damaged connector, control module driver fault.
• P1173 — OBD2 code P1173 flags a problem with the fuel delivery and mixture control (fuel rail sensor in-range low failure). Short, gentle driving to a shop is usually possible. Common culprits: faulty fuel rail pressure sensor or wiring, contaminated or incorrect fuel, vacuum or intake leaks skewing the mixture.
• P1174 — Fuel Rail Sensor In-Range High Failure (P1174): a powertrain (engine/transmission) fault affecting the fuel delivery and mixture control. Short, gentle driving to a shop is usually possible. Most often caused by faulty fuel pressure regulator, faulty fuel rail pressure sensor or wiring, vacuum or intake leaks skewing the mixture.
• P1175 — OBD2 code P1175 flags a problem with the sensor and actuator circuits (ESO - engine shut off solenoid fault). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, corroded, loose or damaged connector, blown fuse feeding the circuit.
• P1176 — Rotor Sensor Fault (P1176): 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.
• P1177 — Rotor Control Fault (P1177): 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, open or shorted wiring in the circuit.
• P1178 — Rotor Calibration Fault (P1178): 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.
• P1179 — P1179 — Long-Term Fuel Trim Too Rich. P1179 usually does not require an immediate shutdown, but continued rich operation can damage the catalytic converter and increase fuel use.
• P1180 — OBD2 code P1180 flags a problem with the sensor and actuator circuits (cam sensor fault). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, corroded, loose or damaged connector, open or shorted wiring in the circuit.
• P1181 — Cam Control Fault (P1181): 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, control module driver fault.
• P1182 — P1182 — Cam Calibration Fault. 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.
• P1183 — Synchronization Fault (P1183): 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, poor ground connection.