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

• B2450 — OBD2 code B2450 flags a problem with the diesel glow plug system (aux heater glow plug circuit open). The car is usually drivable while you plan the repair. Common culprits: faulty glow plug relay or control module, burned-out glow plug, corroded glow plug connectors.
• B2451 — Aux Heater Fuel Pump Circuit Short to Ground (B2451): a body electrical fault affecting the fuel delivery and mixture control. Short, gentle driving to a shop is usually possible. Most often caused by weak fuel pump or clogged fuel filter, vacuum or intake leaks skewing the mixture, contaminated or incorrect fuel.
• B2452 — B2452 — Aux Heater Fuel Pump Circuit Open. A fault in the fuel delivery and mixture control. Short, gentle driving to a shop is usually possible. Typical causes: faulty fuel rail pressure sensor or wiring, vacuum or intake leaks skewing the mixture, faulty fuel pressure regulator.
• B2453 — Aux Heater Blower Fan Circuit Short to Ground (B2453): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by blown fuse or failed relay, faulty switch, motor or actuator of the affected system, damaged wiring in door jambs or wet areas.
• B2454 — Aux Heater Blower Fan Circuit Open (B2454): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by corroded or loose connectors, damaged wiring in door jambs or wet areas, blown fuse or failed relay.
• B2455 — Aux Heater Blower Faulted (B2455): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by blown fuse or failed relay, corroded or loose connectors, body control module (BCM) fault.
• B2456 — Aux Heater Coolant Sensor Circuit Short to Ground (B2456): a body electrical 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, water pump or radiator issues, thermostat stuck open or closed.
• B2457 — OBD2 code B2457 flags a problem with the engine cooling and temperature control (aux heater coolant sensor circuit open). Short, gentle driving to a shop is usually possible. Common culprits: faulty coolant temperature sensor, failed cooling fan or fan relay, thermostat stuck open or closed.
• B2458 — Aux Heater Overheat Sensor Circuit Short to Ground (B2458): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by corroded or loose connectors, damaged wiring in door jambs or wet areas, blown fuse or failed relay.
• B2459 — OBD2 code B2459 flags a problem with the body electrical system (aux heater overheat sensor circuit open). The car is usually drivable while you plan the repair. Common culprits: body control module (BCM) fault, faulty switch, motor or actuator of the affected system, damaged wiring in door jambs or wet areas.
• B2460 — Aux Heater Flame Sensor Circuit Short to Ground (B2460): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by body control module (BCM) fault, faulty switch, motor or actuator of the affected system, blown fuse or failed relay.
• B2461 — Aux Heater Flame Sensor Circuit Open (B2461): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by corroded or loose connectors, faulty switch, motor or actuator of the affected system, blown fuse or failed relay.
• B2462 — Aux Heater Flame Out Fault (B2462): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by corroded or loose connectors, faulty switch, motor or actuator of the affected system, damaged wiring in door jambs or wet areas.
• B2463 — B2463 — Aux Heater Overheat Fault. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: body control module (BCM) fault, damaged wiring in door jambs or wet areas, blown fuse or failed relay.
• B2464 — B2464 — Aux Heater Start Time Exceeded. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: faulty switch, motor or actuator of the affected system, damaged wiring in door jambs or wet areas, blown fuse or failed relay.
• B2465 — Aux Heater Start Counter Overrun/System Locked (same as below ?) (B2465): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by damaged wiring in door jambs or wet areas, faulty switch, motor or actuator of the affected system, corroded or loose connectors.
• B2466 — Aux Heater Overheat Counter Overrun/System Locked (B2466): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by faulty switch, motor or actuator of the affected system, damaged wiring in door jambs or wet areas, corroded or loose connectors.
• B2467 — B2467 — Aux Heater Cool Down Time Exceeded (may be con to a453-5 ). A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: corroded or loose connectors, blown fuse or failed relay, body control module (BCM) fault.
• B2468 — OBD2 code B2468 flags a problem with the engine cooling and temperature control (aux heater coolant pump circuit short to ground). Short, gentle driving to a shop is usually possible. Common culprits: low coolant level or air in the system, failed cooling fan or fan relay, water pump or radiator issues.
• B2469 — B2469 — Aux Heater Coolant Pump Circuit Open. A fault in the engine cooling and temperature control. Short, gentle driving to a shop is usually possible. Typical causes: thermostat stuck open or closed, wiring faults in the sensor circuit, failed cooling fan or fan relay.
• B2470 — B2470 — Interior Fan Control Circuit Short to Ground. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: corroded or loose connectors, damaged wiring in door jambs or wet areas, blown fuse or failed relay.
• B2471 — Interior Fan Control Circuit Open (B2471): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by faulty switch, motor or actuator of the affected system, corroded or loose connectors, blown fuse or failed relay.
• B2472 — B2472 — Fog Lamp Switch Failure. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: blown fuse or failed relay, damaged wiring in door jambs or wet areas, faulty switch, motor or actuator of the affected system.
• B2473 — Passenger Door Disarm Switch ckt Short to Ground (B2473): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by body control module (BCM) fault, corroded or loose connectors, faulty switch, motor or actuator of the affected system.