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

• B1968 — OBD2 code B1968 flags a problem with the body electrical system (A/C water pump detection circuit failure). The car is usually drivable while you plan the repair. Common culprits: damaged wiring in door jambs or wet areas, blown fuse or failed relay, body control module (BCM) fault.
• B1969 — A/C Clutch Magnetic Control Circuit Failure (B1969): 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.
• B1970 — OBD2 code B1970 flags a problem with the body electrical system (passenger seatback forward switch circuit short to ground). The car is usually drivable while you plan the repair. Common culprits: corroded or loose connectors, blown fuse or failed relay, faulty switch, motor or actuator of the affected system.
• B1971 — OBD2 code B1971 flags a problem with the body electrical system (passenger seatback rearward switch circuit short to ground). The car is usually drivable while you plan the repair. Common culprits: corroded or loose connectors, damaged wiring in door jambs or wet areas, body control module (BCM) fault.
• B1972 — OBD2 code B1972 flags a problem with the body electrical system (passenger rear seat up switch circuit short to battery). The car is usually drivable while you plan the repair. Common culprits: body control module (BCM) fault, corroded or loose connectors, damaged wiring in door jambs or wet areas.
• B1973 — Passenger Rear Seat Down Switch Circuit Short to Battery (B1973): 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.
• B1974 — B1974 — B1974 — Passenger Rear Seat Up Switch Circuit Short To Ground: Causes, Symptoms & Fix. 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, blown fuse or failed relay, damaged wiring in door jambs or wet areas.
• B1975 — B1975 — B1975 — Passenger Rear Seat Down Switch Circuit Short To Ground: Causes, Symptoms & Fix. 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.
• B1976 — OBD2 code B1976 flags a problem with the body electrical system (B1976 — driver rear seat up switch circuit short to battery: 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.
• B1977 — OBD2 code B1977 flags a problem with the body electrical system (B1977 — driver rear seat down switch circuit short to battery: causes, symptoms & fix). 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.
• B1978 — B1978 — Driver Rear Seat Up Switch Circuit Short To Ground: Causes, Symptoms & Fix (B1978): a vehicle 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.
• B1979 — OBD2 code B1979 flags a problem with the body electrical system (passenger seat rearward switch circuit short to battery). 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, faulty switch, motor or actuator of the affected system.
• B1980 — B1980 — Bulb - Outage Condition Detected. 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.
• B1981 — OBD2 code B1981 flags a problem with the body electrical system (memory off switch circuit short to battery). The car is usually drivable while you plan the repair. Common culprits: corroded or loose connectors, body control module (BCM) fault, faulty switch, motor or actuator of the affected system.
• B1982 — OBD2 code B1982 flags a problem with the body electrical system (B1982 — device power circuit high: causes, symptoms & fix). The car is usually drivable while you plan the repair. Common culprits: faulty switch, motor or actuator of the affected system, corroded or loose connectors, body control module (BCM) fault.
• B1983 — B1983 — B1983 — Device Power Circuit Low: Causes, Symptoms & Fix. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: blown fuse or failed relay, body control module (BCM) fault, damaged wiring in door jambs or wet areas.
• B1984 — OBD2 code B1984 flags a problem with the body electrical system (seat switch lumbar inflate circuit failure). The car is usually drivable while you plan the repair. Common culprits: damaged wiring in door jambs or wet areas, body control module (BCM) fault, faulty switch, motor or actuator of the affected system.
• B1985 — OBD2 code B1985 flags a problem with the body electrical system (seat switch lumbar deflate circuit failure). The car is usually drivable while you plan the repair. Common culprits: body control module (BCM) fault, damaged wiring in door jambs or wet areas, faulty switch, motor or actuator of the affected system.
• B1986 — OBD2 code B1986 flags a problem with the throttle and intake air metering (B1986 — lamp map input circuit failure: causes, symptoms & fix). Short, gentle driving to a shop is usually possible. Common culprits: contaminated or failed MAF/MAP sensor, faulty throttle position sensor or pedal sensor, failed electronic throttle motor.
• B1987 — Pedal Forward / Rearward Motor Stalled (B1987): 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.
• B1988 — OBD2 code B1988 flags a problem with the body electrical system (pedal position forward switch circuit short to battery). 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.
• B1989 — B1989 — Pedal Position Rearward Switch 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, blown fuse or failed relay, damaged wiring in door jambs or wet areas.
• B1990 — Pedal Forward / Rearward Potentiometer Feedback Circuit Failure (B1990): 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, blown fuse or failed relay.
• B1991 — B1991 — Pedal Forward / Rearward Potentiometer Feedback 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, faulty switch, motor or actuator of the affected system, corroded or loose connectors.