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

• P1931 — P1931 — Fuel Additive Pump Overvoltage. P1931 identifies excessive voltage in the fuel additive pump control circuit.
• P1932 — P1932 — Fuel Additive Low-Level Signal. P1932 normally requires prompt attention rather than immediate shutdown.
• P1933 — P1933 — Fuel Level Signal Malfunction. P1933 typically does not by itself mean the engine will stop, but the displayed fuel level may be inaccurate.
• P1934 — P1934 — Vehicle Speed Signal Circuit Malfunction. P1934 can affect transmission shifting and driver-assistance functions that depend on vehicle speed.
• P1935 — P1935 — Brake Switch/Sensor Signal Fault. If the brake pedal feels normal and the brake lights operate correctly, drive cautiously and arrange prompt diagnosis because ABS protection may be unavailable.
• P1936 — P1936 — Clutch Switch/Sensor Signal Fault. P1936 may not prevent normal driving if the clutch and required functions operate correctly, but related cruise or interlock functions may be disabled.
• P1937 — P1937 — Additional Heater Control Circuit Open. P1937 can leave the cabin without adequate heat or defrosting.
• P1938 — P1938 — Additional Heater Supply Voltage Too Low. P1938 does not usually require immediate stopping, but the additional heater may not operate.
• P1939 — P1939 — Additional Heater Control Supply Overvoltage. P1939 usually does not require immediate stopping if the vehicle remains stable and the climate system still heats normally.
• P2000 — NOx Adsorber Efficiency Below Threshold Bank 1 (P2000): 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, blown fuse feeding the circuit.
• P2001 — NOx Adsorber Efficiency Below Threshold Bank 2 (P2001): 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.
• P2003 — OBD2 code P2003 flags a problem with the diesel particulate filter (DPF) (diesel particulate filter efficiency below threshold bank 2). Short, gentle driving to a shop is usually possible. Common culprits: faulty differential pressure or exhaust temperature sensor, excessive ash loading (end of DPF life), engine faults producing excess soot (EGR, injectors).
• P2005 — P2005 — Intake Manifold Runner Control Stuck Open Bank 2. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: poor ground connection, corroded, loose or damaged connector, control module driver fault.
• P200A — OBD2 code P200A flags a problem with the sensor and actuator circuits (intake manifold runner performance bank 1). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, poor ground connection, control module driver fault.
• P200B — Intake Manifold Runner Performance Bank 2 (P200B): 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, poor ground connection, open or shorted wiring in the circuit.
• P200C — P200C — Diesel Particulate Filter Over Temperature Bank 1. A fault in the diesel particulate filter (DPF). Short, gentle driving to a shop is usually possible. Typical causes: engine faults producing excess soot (EGR, injectors), soot-overloaded DPF from short-trip driving, faulty differential pressure or exhaust temperature sensor.
• P200D — P200D — Diesel Particulate Filter Over Temperature Bank 2. A fault in the diesel particulate filter (DPF). Short, gentle driving to a shop is usually possible. Typical causes: engine faults producing excess soot (EGR, injectors), soot-overloaded DPF from short-trip driving, excessive ash loading (end of DPF life).
• P200E — P200E — Catalyst System Over Temperature Bank 1. A fault in the catalytic converter efficiency monitoring. The car is usually drivable while you plan the repair. Typical causes: faulty downstream or upstream oxygen sensor, aged or contaminated catalytic converter, engine misfires damaging the catalyst.
• P200F — OBD2 code P200F flags a problem with the catalytic converter efficiency monitoring (catalyst system over temperature bank 2). The car is usually drivable while you plan the repair. Common culprits: aged or contaminated catalytic converter, faulty downstream or upstream oxygen sensor, oil or coolant entering the exhaust.
• P2010 — P2010 — Intake Manifold Runner Control Circuit High Bank 1. 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.
• P2011 — Intake Manifold Runner Control Circuit/Open Bank 2 (P2011): 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, control module driver fault, poor ground connection.
• P2012 — P2012 — Intake Manifold Runner Control Circuit Low Bank 2. 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, blown fuse feeding the circuit.
• P2013 — OBD2 code P2013 flags a problem with the sensor and actuator circuits (intake manifold runner control circuit high bank 2). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, blown fuse feeding the circuit, corroded, loose or damaged connector.
• P2014 — OBD2 code P2014 flags a problem with the sensor and actuator circuits (intake manifold runner position sensor/switch circuit bank 1). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector.