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

• B1920 — Air Bag Passenger Circuit Failure (B1920): a body electrical fault affecting the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Most often caused by SRS control module fault or stored crash data, faulty impact or occupancy sensor, damaged wiring under seats or in the steering column.
• B1921 — Air Bag Diagnostic Monitor Ground Circuit Open (B1921): a body electrical fault affecting the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Most often caused by damaged wiring under seats or in the steering column, faulty impact or occupancy sensor, depleted backup battery or low system voltage.
• B1922 — B1922 — Air Bag Safing Sensor Output Circuit Short To Battery. A fault in the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Typical causes: depleted backup battery or low system voltage, failed clockspring (driver airbag circuit), damaged wiring under seats or in the steering column.
• B1923 — B1923 — Air Bag Memory Clear Circuit Short To Ground. A fault in the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Typical causes: SRS control module fault or stored crash data, depleted backup battery or low system voltage, failed clockspring (driver airbag circuit).
• B1924 — OBD2 code B1924 flags a problem with the airbag / restraint system (SRS) (air bag internal diagnostic monitor fault or system disarm fault). Short, gentle driving to a shop is usually possible. Common culprits: depleted backup battery or low system voltage, faulty impact or occupancy sensor, failed clockspring (driver airbag circuit).
• B1925 — B1925 — Air Bag Passenger Circuit Short To Battery. A fault in the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Typical causes: SRS control module fault or stored crash data, damaged wiring under seats or in the steering column, failed clockspring (driver airbag circuit).
• B1926 — OBD2 code B1926 flags a problem with the airbag / restraint system (SRS) (air bag passenger pressure switch circuit failure). Short, gentle driving to a shop is usually possible. Common culprits: faulty impact or occupancy sensor, failed clockspring (driver airbag circuit), damaged wiring under seats or in the steering column.
• B1927 — OBD2 code B1927 flags a problem with the airbag / restraint system (SRS) (passenger side airbag fault). Short, gentle driving to a shop is usually possible. Common culprits: SRS control module fault or stored crash data, failed clockspring (driver airbag circuit), damaged wiring under seats or in the steering column.
• B1928 — B1928 — Air Bag Safing Sensor Output Circuit Failure. A fault in the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Typical causes: damaged wiring under seats or in the steering column, depleted backup battery or low system voltage, faulty impact or occupancy sensor.
• B1929 — Air Bag Safing Sensor Output Circuit Open (B1929): a body electrical fault affecting the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Most often caused by faulty impact or occupancy sensor, depleted backup battery or low system voltage, failed clockspring (driver airbag circuit).
• B1930 — B1930 — Air Bag Safing Sensor Output Circuit Short To Ground. A fault in the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Typical causes: depleted backup battery or low system voltage, damaged wiring under seats or in the steering column, SRS control module fault or stored crash data.
• B1931 — OBD2 code B1931 flags a problem with the airbag / restraint system (SRS) (air bag crash sensor #1 feed/return circuit failure). Short, gentle driving to a shop is usually possible. Common culprits: damaged wiring under seats or in the steering column, SRS control module fault or stored crash data, failed clockspring (driver airbag circuit).
• B1932 — OBD2 code B1932 flags a problem with the airbag / restraint system (SRS) (air bag driver circuit open). Short, gentle driving to a shop is usually possible. Common culprits: damaged wiring under seats or in the steering column, failed clockspring (driver airbag circuit), depleted backup battery or low system voltage.
• B1933 — Air Bag Passenger Circuit Open (B1933): a body electrical fault affecting the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Most often caused by SRS control module fault or stored crash data, faulty impact or occupancy sensor, depleted backup battery or low system voltage.
• B1934 — Air Bag Driver Inflator Circuit Resistance Low on Squib (B1934): a body electrical fault affecting the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Most often caused by SRS control module fault or stored crash data, faulty impact or occupancy sensor, damaged wiring under seats or in the steering column.
• B1935 — B1935 — Air Bag Passenger Inflator Circuit Resistance Low on Squib. A fault in the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Typical causes: faulty impact or occupancy sensor, depleted backup battery or low system voltage, failed clockspring (driver airbag circuit).
• B1936 — OBD2 code B1936 flags a problem with the airbag / restraint system (SRS) (air bag driver circuit short to ground). Short, gentle driving to a shop is usually possible. Common culprits: depleted backup battery or low system voltage, damaged wiring under seats or in the steering column, faulty impact or occupancy sensor.
• B1937 — Air Bag Passenger Pressure Switch Circuit Open (B1937): a body electrical fault affecting the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Most often caused by failed clockspring (driver airbag circuit), SRS control module fault or stored crash data, faulty impact or occupancy sensor.
• B1938 — OBD2 code B1938 flags a problem with the airbag / restraint system (SRS) (air bag passenger circuit short to ground). Short, gentle driving to a shop is usually possible. Common culprits: faulty impact or occupancy sensor, SRS control module fault or stored crash data, depleted backup battery or low system voltage.
• B1939 — Air Bag Passenger Pressure Switch Circuit Short To Ground (B1939): a body electrical fault affecting the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Most often caused by failed clockspring (driver airbag circuit), depleted backup battery or low system voltage, faulty impact or occupancy sensor.
• B1940 — OBD2 code B1940 flags a problem with the airbag / restraint system (SRS) (B1940 — air bag crash sensor #2 ground circuit open: causes, symptoms & fix). Short, gentle driving to a shop is usually possible. Common culprits: failed clockspring (driver airbag circuit), damaged wiring under seats or in the steering column, SRS control module fault or stored crash data.
• B1941 — OBD2 code B1941 flags a problem with the airbag / restraint system (SRS) (air bag crash sensor #1 feed/return circuit open). Short, gentle driving to a shop is usually possible. Common culprits: damaged wiring under seats or in the steering column, depleted backup battery or low system voltage, failed clockspring (driver airbag circuit).
• B1942 — B1942 — Air Bag Crash Sensor #2 Feed/Return Circuit Open. A fault in the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Typical causes: damaged wiring under seats or in the steering column, faulty impact or occupancy sensor, depleted backup battery or low system voltage.
• B1943 — B1943 — Air Bag Crash Sensor #1 Ground Circuit Short To Ground. A fault in the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Typical causes: damaged wiring under seats or in the steering column, failed clockspring (driver airbag circuit), SRS control module fault or stored crash data.