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

• B1248 — OBD2 code B1248 flags a problem with the body electrical system (B1248 — passenger's seatback autoglide rearward switch circuit short to ground: causes, symptoms & fix). 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.
• B1249 — OBD2 code B1249 flags a problem with the body electrical system (blend door failure). The car is usually drivable while you plan the repair. Common culprits: blown fuse or failed relay, body control module (BCM) fault, faulty switch, motor or actuator of the affected system.
• B1250 — B1250 — Air Temperature Internal Sensor Circuit Failure. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: body control module (BCM) fault, blown fuse or failed relay, faulty switch, motor or actuator of the affected system.
• B1251 — B1251 — Air Temperature Internal Sensor Circuit Open. 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, body control module (BCM) fault.
• B1252 — Air Temperature Internal Sensor Circuit Short To Battery (B1252): 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, body control module (BCM) fault, blown fuse or failed relay.
• B1253 — OBD2 code B1253 flags a problem with the body electrical system (air temperature internal sensor circuit short to ground). The car is usually drivable while you plan the repair. Common culprits: blown fuse or failed relay, damaged wiring in door jambs or wet areas, body control module (BCM) fault.
• B1254 — Air Temperature External Sensor Circuit Failure (B1254): 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, faulty switch, motor or actuator of the affected system.
• B1255 — B1255 — Air Temperature External Sensor Circuit Open. 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.
• B1256 — B1256 — Air Temperature External Sensor Circuit Short To Battery. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: body control module (BCM) fault, blown fuse or failed relay, damaged wiring in door jambs or wet areas.
• B1257 — B1257 — Air Temperature External Sensor Circuit Short To Ground. 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, blown fuse or failed relay, corroded or loose connectors.
• B1258 — Solar Radiation Sensor Circuit Failure (B1258): 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, faulty switch, motor or actuator of the affected system.
• B1259 — OBD2 code B1259 flags a problem with the body electrical system (solar radiation sensor circuit open). The car is usually drivable while you plan the repair. Common culprits: damaged wiring in door jambs or wet areas, corroded or loose connectors, body control module (BCM) fault.
• B1260 — B1260 — Solar Radiation Sensor Circuit 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, blown fuse or failed relay, body control module (BCM) fault.
• B1261 — Solar Radiation Sensor Circuit Short To Ground (B1261): 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.
• B1262 — Servo Motor Defrost Circuit Failure (B1262): 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, damaged wiring in door jambs or wet areas.
• B1263 — Servo Motor Vent Circuit Failure (B1263): 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, damaged wiring in door jambs or wet areas, faulty switch, motor or actuator of the affected system.
• B1264 — OBD2 code B1264 flags a problem with the body electrical system (servo motor foot circuit failure). The car is usually drivable while you plan the repair. Common culprits: blown fuse or failed relay, body control module (BCM) fault, corroded or loose connectors.
• B1265 — Servo Motor Coolair Bypass Circuit Failure (B1265): 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, body control module (BCM) fault.
• B1266 — OBD2 code B1266 flags a problem with the body electrical system (servo motor airintake left circuit failure). The car is usually drivable while you plan the repair. Common culprits: body control module (BCM) fault, blown fuse or failed relay, corroded or loose connectors.
• B1267 — B1267 — Servo Motor Airintake Right Circuit Failure. 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, corroded or loose connectors.
• B1268 — B1268 — Servo Motor Potentiometer Defrost Circuit Failure. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: corroded or loose connectors, faulty switch, motor or actuator of the affected system, damaged wiring in door jambs or wet areas.
• B1269 — OBD2 code B1269 flags a problem with the body electrical system (servo motor potentiometer defrost circuit open). The car is usually drivable while you plan the repair. Common culprits: corroded or loose connectors, faulty switch, motor or actuator of the affected system, damaged wiring in door jambs or wet areas.
• B1270 — OBD2 code B1270 flags a problem with the body electrical system (servo motor potentiometer defrost circuit short to battery). The car is usually drivable while you plan the repair. Common culprits: faulty switch, motor or actuator of the affected system, damaged wiring in door jambs or wet areas, body control module (BCM) fault.
• B1271 — Servo Motor Potentiometer Defrost Circuit Short To Ground (B1271): 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, faulty switch, motor or actuator of the affected system.