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

• P06A9 — OBD2 code P06A9 flags a problem with the sensor and actuator circuits (sensor reference voltage "D" circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P06AA — PCM/ECM/TCM Internal Temperature "B" Too High (P06AA): 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, blown fuse feeding the circuit.
• P06AB — P06AB — PCM/ECM/TCM Internal Temperature Sensor "B" Circuit. 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, faulty sensor or actuator of the affected circuit, control module driver fault.
• P06AC — PCM/ECM/TCM Internal Temperature Sensor "B" Range/Performance (P06AC): 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, poor ground connection.
• P06AD — P06AD — PCM/ECM/TCM Internal Temperature Sensor "B" Circuit Low. 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, control module driver fault.
• P06AE — OBD2 code P06AE flags a problem with the sensor and actuator circuits (PCM/ECM/TCM internal temperature sensor "B" circuit high). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, open or shorted wiring in the circuit, control module driver fault.
• P06AF — Torque Management System - Forced Engine Shutdown (P06AF): 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, blown fuse feeding the circuit, open or shorted wiring in the circuit.
• P06B0 — OBD2 code P06B0 flags a problem with the sensor and actuator circuits (sensor power supply "A" circuit/open). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, poor ground connection, blown fuse feeding the circuit.
• P06B1 — P06B1 — Sensor Power Supply "A" Circuit Low. 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, faulty sensor or actuator of the affected circuit.
• P06B2 — P06B2 — Sensor Power Supply "A" Circuit High. 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, faulty sensor or actuator of the affected circuit.
• P06B3 — Sensor Power Supply "B" Circuit/Open (P06B3): 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.
• P06B4 — P06B4 — Sensor Power Supply "B" Circuit Low. 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, open or shorted wiring in the circuit.
• P06B5 — OBD2 code P06B5 flags a problem with the sensor and actuator circuits (sensor power supply "B" circuit high). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, poor ground connection, open or shorted wiring in the circuit.
• P06B6 — Internal Control Module Knock Sensor Processor 1 Performance (P06B6): a powertrain (engine/transmission) fault affecting the knock (detonation) detection. Short, gentle driving to a shop is usually possible. Most often caused by low-octane or contaminated fuel, failed knock sensor, loose sensor mounting or incorrect torque.
• P06B7 — OBD2 code P06B7 flags a problem with the knock (detonation) detection (internal control module knock sensor processor 2 performance). Short, gentle driving to a shop is usually possible. Common culprits: loose sensor mounting or incorrect torque, failed knock sensor, damaged knock sensor wiring or connector.
• P06B8 — P06B8 — Internal Control Module Non-Volatile Random Access Memory (NVRAM) 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, blown fuse feeding the circuit, open or shorted wiring in the circuit.
• P06B9 — P06B9 — Cylinder 1 Glow Plug Circuit Range/Performance. A fault in the diesel glow plug system. The car is usually drivable while you plan the repair. Typical causes: faulty glow plug relay or control module, burned-out glow plug, blown fuse in the glow plug circuit.
• P06BA — Cylinder 2 Glow Plug Circuit Range/Performance (P06BA): a powertrain (engine/transmission) fault affecting the diesel glow plug system. The car is usually drivable while you plan the repair. Most often caused by damaged glow plug wiring or connector, faulty glow plug relay or control module, blown fuse in the glow plug circuit.
• P06BB — Cylinder 3 Glow Plug Circuit Range/Performance (P06BB): a powertrain (engine/transmission) fault affecting the diesel glow plug system. The car is usually drivable while you plan the repair. Most often caused by damaged glow plug wiring or connector, faulty glow plug relay or control module, corroded glow plug connectors.
• P06BC — OBD2 code P06BC flags a problem with the diesel glow plug system (cylinder 4 glow plug circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: blown fuse in the glow plug circuit, faulty glow plug relay or control module, corroded glow plug connectors.
• P06BD — OBD2 code P06BD flags a problem with the diesel glow plug system (cylinder 5 glow plug circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: burned-out glow plug, damaged glow plug wiring or connector, blown fuse in the glow plug circuit.
• P06BE — OBD2 code P06BE flags a problem with the diesel glow plug system (cylinder 6 glow plug circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: damaged glow plug wiring or connector, faulty glow plug relay or control module, blown fuse in the glow plug circuit.
• P06BF — OBD2 code P06BF flags a problem with the diesel glow plug system (cylinder 7 glow plug circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: burned-out glow plug, corroded glow plug connectors, faulty glow plug relay or control module.
• P06C0 — OBD2 code P06C0 flags a problem with the diesel glow plug system (cylinder 8 glow plug circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: damaged glow plug wiring or connector, faulty glow plug relay or control module, blown fuse in the glow plug circuit.