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

• B1368 — Ignition Tach Circuit Open (B1368): a body electrical fault affecting the ignition system. Short, gentle driving to a shop is usually possible. Most often caused by faulty ignition control circuit in the ECM, damaged coil wiring or connector, moisture or oil in the spark plug wells.
• B1369 — OBD2 code B1369 flags a problem with the ignition system (ignition tach circuit short to battery). Short, gentle driving to a shop is usually possible. Common culprits: damaged coil wiring or connector, faulty ignition control circuit in the ECM, moisture or oil in the spark plug wells.
• B1370 — OBD2 code B1370 flags a problem with the ignition system (ignition tach circuit short to ground). Short, gentle driving to a shop is usually possible. Common culprits: worn spark plugs or wrong plug gap, damaged coil wiring or connector, faulty ignition control circuit in the ECM.
• B1371 — OBD2 code B1371 flags a problem with the body electrical system (illuminated entry relay circuit failure). The car is usually drivable while you plan the repair. Common culprits: faulty switch, motor or actuator of the affected system, blown fuse or failed relay, body control module (BCM) fault.
• B1372 — Illuminated Entry Relay Circuit Open (B1372): 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, damaged wiring in door jambs or wet areas.
• B1373 — B1373 — Illuminated Entry Relay Short To Battery. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: damaged wiring in door jambs or wet areas, corroded or loose connectors, faulty switch, motor or actuator of the affected system.
• B1374 — Illuminated Entry Relay Short To Ground (B1374): 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, body control module (BCM) fault, corroded or loose connectors.
• B1375 — OBD2 code B1375 flags a problem with the body electrical system (oil change lamp circuit open). The car is usually drivable while you plan the repair. Common culprits: faulty switch, motor or actuator of the affected system, body control module (BCM) fault, corroded or loose connectors.
• B1376 — B1376 — Oil Change Lamp Circuit Short To Battery. 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, body control module (BCM) fault, blown fuse or failed relay.
• B1377 — Oil Change Lamp Circuit Failure (B1377): 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, corroded or loose connectors, blown fuse or failed relay.
• B1378 — Oil Change Lamp Circuit Short To Ground (B1378): 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, body control module (BCM) fault, damaged wiring in door jambs or wet areas.
• B1379 — Oil Change Reset Button Circuit Short To Ground (B1379): 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, damaged wiring in door jambs or wet areas, body control module (BCM) fault.
• B1380 — Oil Change Reset Button Circuit Failure (B1380): 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.
• B1381 — OBD2 code B1381 flags a problem with the body electrical system (oil change reset button circuit open). The car is usually drivable while you plan the repair. Common culprits: blown fuse or failed relay, faulty switch, motor or actuator of the affected system, corroded or loose connectors.
• B1382 — B1382 — Oil Change Reset Button Circuit Short To Battery. 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, corroded or loose connectors, damaged wiring in door jambs or wet areas.
• B1383 — Oil Level Lamp Circuit Short To Battery (B1383): 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, body control module (BCM) fault, corroded or loose connectors.
• B1384 — OBD2 code B1384 flags a problem with the body electrical system (oil level lamp circuit failure). The car is usually drivable while you plan the repair. Common culprits: body control module (BCM) fault, blown fuse or failed relay, faulty switch, motor or actuator of the affected system.
• B1385 — Oil Level Lamp Circuit Open (B1385): 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, damaged wiring in door jambs or wet areas.
• B1386 — OBD2 code B1386 flags a problem with the body electrical system (oil level lamp circuit short to ground). The car is usually drivable while you plan the repair. Common culprits: faulty switch, motor or actuator of the affected system, blown fuse or failed relay, corroded or loose connectors.
• B1387 — B1387 — Oil Temperature Sensor Circuit Open. 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, corroded or loose connectors.
• B1388 — Oil Temperature Sensor Circuit Short To Battery (B1388): 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, blown fuse or failed relay, body control module (BCM) fault.
• B1389 — Oil Temperature Sensor Circuit Failure (B1389): 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, blown fuse or failed relay, faulty switch, motor or actuator of the affected system.
• B1390 — B1390 — Oil Temperature Sensor Circuit Short To Ground. 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.
• B1391 — Oil Level Switch Circuit Failure (B1391): 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.