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

• P0923 — P0923 — Gear Shift Forward Actuator Circuit High. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: low or degraded transmission fluid, failed shift or pressure control solenoid, valve body wear.
• P0924 — Gear Shift Reverse Actuator Circuit/Open (P0924): a powertrain (engine/transmission) fault affecting the automatic transmission control. Short, gentle driving to a shop is usually possible. Most often caused by wiring or connector faults in the valve body harness, failed shift or pressure control solenoid, faulty transmission speed sensor.
• P0925 — P0925 — Gear Shift Reverse Actuator Circuit Range/Performance. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: faulty transmission speed sensor, failed shift or pressure control solenoid, valve body wear.
• P0926 — OBD2 code P0926 flags a problem with the automatic transmission control (gear shift reverse actuator circuit low). Short, gentle driving to a shop is usually possible. Common culprits: faulty transmission speed sensor, internal mechanical wear (clutches, torque converter), valve body wear.
• P0927 — OBD2 code P0927 flags a problem with the automatic transmission control (gear shift reverse actuator circuit high). Short, gentle driving to a shop is usually possible. Common culprits: internal mechanical wear (clutches, torque converter), valve body wear, faulty transmission speed sensor.
• P0928 — P0928 — Gear Shift Lock Solenoid/Actuator Control Circuit "A"/Open. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: wiring or connector faults in the valve body harness, failed shift or pressure control solenoid, low or degraded transmission fluid.
• P0929 — Gear Shift Lock Solenoid/Actuator Control Circuit "A" Range/Performance (P0929): a powertrain (engine/transmission) fault affecting the automatic transmission control. Short, gentle driving to a shop is usually possible. Most often caused by failed shift or pressure control solenoid, low or degraded transmission fluid, wiring or connector faults in the valve body harness.
• P092A — OBD2 code P092A flags a problem with the automatic transmission control (gear shift lock solenoid/actuator control circuit "b"/open). Short, gentle driving to a shop is usually possible. Common culprits: internal mechanical wear (clutches, torque converter), low or degraded transmission fluid, valve body wear.
• P092B — OBD2 code P092B flags a problem with the automatic transmission control (gear shift lock solenoid/actuator control circuit "B" range/performance). Short, gentle driving to a shop is usually possible. Common culprits: internal mechanical wear (clutches, torque converter), failed shift or pressure control solenoid, valve body wear.
• P092C — P092C — Gear Shift Lock Solenoid/Actuator Control Circuit "B" Low. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: wiring or connector faults in the valve body harness, failed shift or pressure control solenoid, faulty transmission speed sensor.
• P092D — OBD2 code P092D flags a problem with the automatic transmission control (gear shift lock solenoid/actuator control circuit "B" high). Short, gentle driving to a shop is usually possible. Common culprits: failed shift or pressure control solenoid, faulty transmission speed sensor, wiring or connector faults in the valve body harness.
• P0930 — OBD2 code P0930 flags a problem with the automatic transmission control (gear shift lock solenoid/actuator control circuit "A" low). Short, gentle driving to a shop is usually possible. Common culprits: faulty transmission speed sensor, low or degraded transmission fluid, internal mechanical wear (clutches, torque converter).
• P0931 — Gear Shift Lock Solenoid/Actuator Control Circuit "A" High (P0931): a powertrain (engine/transmission) fault affecting the automatic transmission control. Short, gentle driving to a shop is usually possible. Most often caused by valve body wear, faulty transmission speed sensor, wiring or connector faults in the valve body harness.
• P0932 — OBD2 code P0932 flags a problem with the sensor and actuator circuits (hydraulic pressure sensor circuit). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• P0933 — Hydraulic Pressure Sensor Range/Performance (P0933): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by blown fuse feeding the circuit, control module driver fault, corroded, loose or damaged connector.
• P0934 — P0934 — Hydraulic Pressure Sensor Circuit Low. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: blown fuse feeding the circuit, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• P0935 — OBD2 code P0935 flags a problem with the sensor and actuator circuits (hydraulic pressure sensor circuit high). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, blown fuse feeding the circuit, corroded, loose or damaged connector.
• P0936 — Hydraulic Pressure Sensor Circuit Intermittent (P0936): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by control module driver fault, poor ground connection, blown fuse feeding the circuit.
• P0937 — OBD2 code P0937 flags a problem with the sensor and actuator circuits (hydraulic oil temperature sensor circuit). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, open or shorted wiring in the circuit, control module driver fault.
• P0938 — P0938 — Hydraulic Oil Temperature Sensor Range/Performance. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: faulty sensor or actuator of the affected circuit, control module driver fault, blown fuse feeding the circuit.
• P0939 — Hydraulic Oil Temperature Sensor Circuit Low (P0939): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by open or shorted wiring in the circuit, blown fuse feeding the circuit, corroded, loose or damaged connector.
• P0940 — P0940 — Hydraulic Oil Temperature Sensor Circuit High. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, faulty sensor or actuator of the affected circuit, blown fuse feeding the circuit.
• P0941 — OBD2 code P0941 flags a problem with the sensor and actuator circuits (hydraulic oil temperature sensor circuit intermittent). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, poor ground connection, blown fuse feeding the circuit.
• P0942 — Hydraulic Pressure Unit (P0942): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by control module driver fault, poor ground connection, open or shorted wiring in the circuit.