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.

P0601 — Internal Control Module Memory Check Sum Error (P0601): 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, open or shorted wiring in the circuit.
P0602 — Control Module Programming Error (P0602): 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.
P0603 — P0603 — Internal Control Module Keep Alive Memory (KAM) Error. 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, blown fuse feeding the circuit.
P0604 — OBD2 code P0604 flags a problem with the sensor and actuator circuits (internal control module random access memory (RAM) error). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit, control module driver fault.
P0605 — Internal Control Module Read Only Memory (ROM) Error (P0605): 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, control module driver fault.
P0606 — OBD2 code P0606 flags a problem with the sensor and actuator circuits (PCM processor fault). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, control module driver fault, corroded, loose or damaged connector.
P0607 — Control Module Performance (P0607): 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, corroded, loose or damaged connector.
P0608 — P0608 — Control Module VSS Output "A" 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, faulty sensor or actuator of the affected circuit.
P0609 — OBD2 code P0609 flags a problem with the sensor and actuator circuits (control module VSS output "B" malfunction). 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.
P060A — Internal Control Module Monitoring Processor Performance (P060A): 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, corroded, loose or damaged connector.
P060B — Internal Control Module A/D Processing Performance (P060B): 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, open or shorted wiring in the circuit.
P060C — P060C — Internal Control Module Main Processor Performance. 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.
P060D — OBD2 code P060D flags a problem with the throttle and intake air metering (internal control module accelerator pedal position performance). Short, gentle driving to a shop is usually possible. Common culprits: wiring or connector faults in the throttle circuit, dirty throttle body or stuck throttle plate, contaminated or failed MAF/MAP sensor.
P060E — OBD2 code P060E flags a problem with the throttle and intake air metering (internal control module throttle position performance). Short, gentle driving to a shop is usually possible. Common culprits: wiring or connector faults in the throttle circuit, faulty throttle position sensor or pedal sensor, failed electronic throttle motor.
P060F — Internal Control Module Coolant Temperature Performance (P060F): a powertrain (engine/transmission) fault affecting the engine cooling and temperature control. Short, gentle driving to a shop is usually possible. Most often caused by low coolant level or air in the system, thermostat stuck open or closed, faulty coolant temperature sensor.
P0610 — OBD2 code P0610 flags a problem with the sensor and actuator circuits (control module vehicle options error). 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, blown fuse feeding the circuit.
P0611 — P0611 — Fuel Injector Control Module Performance. A fault in the fuel delivery and mixture control. Short, gentle driving to a shop is usually possible. Typical causes: vacuum or intake leaks skewing the mixture, contaminated or incorrect fuel, weak fuel pump or clogged fuel filter.
P0612 — Fuel Injector Control Module Relay Control (P0612): 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 clogged or leaking fuel injectors, weak fuel pump or clogged fuel filter, faulty fuel rail pressure sensor or wiring.
P0613 — OBD2 code P0613 flags a problem with the sensor and actuator circuits (TCM processor). 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.
P0614 — ECM / TCM Incompatible (P0614): 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, open or shorted wiring in the circuit.
P0615 — P0615 — Starter Relay Circuit. 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, faulty sensor or actuator of the affected circuit.
P0616 — Starter Relay Circuit Low (P0616): 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, corroded, loose or damaged connector, control module driver fault.
P0617 — Starter Relay Circuit High (P0617): 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, poor ground connection.
P0618 — P0618 — Alternative Fuel Control Module KAM Error. 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, control module driver fault.