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

• P07B4 — OBD2 code P07B4 flags a problem with the automatic transmission control (transmission park position sensor/switch "A" circuit high). Short, gentle driving to a shop is usually possible. Common culprits: low or degraded transmission fluid, internal mechanical wear (clutches, torque converter), faulty transmission speed sensor.
• P07B5 — P07B5 — Transmission Park Position Sensor/Switch "A" Circuit Performance/Low. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: valve body wear, faulty transmission speed sensor, low or degraded transmission fluid.
• P07B6 — OBD2 code P07B6 flags a problem with the automatic transmission control (transmission park position sensor/switch "A" circuit performance high). Short, gentle driving to a shop is usually possible. Common culprits: faulty transmission speed sensor, internal mechanical wear (clutches, torque converter), failed shift or pressure control solenoid.
• P07B7 — P07B7 — Transmission Park Position Sensor/Switch "A" Circuit Intermittent/Erratic. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: failed shift or pressure control solenoid, valve body wear, internal mechanical wear (clutches, torque converter).
• P07B8 — OBD2 code P07B8 flags a problem with the automatic transmission control (transmission park position sensor/switch "B" circuit open). Short, gentle driving to a shop is usually possible. Common culprits: low or degraded transmission fluid, faulty transmission speed sensor, internal mechanical wear (clutches, torque converter).
• P07B9 — P07B9 — Transmission Park Position Sensor/Switch "B" Circuit Low. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: faulty transmission speed sensor, valve body wear, wiring or connector faults in the valve body harness.
• P07BA — OBD2 code P07BA flags a problem with the automatic transmission control (transmission park position sensor/switch "B" 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.
• P07BB — P07BB — Transmission Park Position Sensor/Switch "B" Circuit Performance/Low. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: valve body wear, faulty transmission speed sensor, failed shift or pressure control solenoid.
• P07BC — Transmission Park Position Sensor/Switch "B" Circuit Performance High (P07BC): 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, low or degraded transmission fluid, wiring or connector faults in the valve body harness.
• P07BD — Transmission Park Position Sensor/Switch "B" Circuit Intermittent/Erratic (P07BD): 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, internal mechanical wear (clutches, torque converter), valve body wear.
• P07BE — Transmission Park Position Sensor/Switch "A"/"B" Correlation (P07BE): 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, failed shift or pressure control solenoid, internal mechanical wear (clutches, torque converter).
• P0800 — Transfer Case Control System (MIL Request) (P0800): 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 poor ground connection, blown fuse feeding the circuit, open or shorted wiring in the circuit.
• P0801 — Reverse Inhibit Control Circuit Malfunction (P0801): 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 poor ground connection, blown fuse feeding the circuit, corroded, loose or damaged connector.
• P0802 — OBD2 code P0802 flags a problem with the automatic transmission control (transmission control system MIL request circuit/open). Short, gentle driving to a shop is usually possible. Common culprits: valve body wear, failed shift or pressure control solenoid, low or degraded transmission fluid.
• P0803 — P0803 — 1-4 Upshift (Skip Shift) Solenoid Control Circuit Malfunction. 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, open or shorted wiring in the circuit.
• P0804 — 1-4 Upshift (Skip Shift) Lamp Control Circuit Malfunction (P0804): 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 faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector, blown fuse feeding the circuit.
• P0805 — P0805 — Clutch Position Sensor Circuit. 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.
• P0806 — Clutch Position Sensor Circuit Range/Performance (P0806): 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 poor ground connection, faulty sensor or actuator of the affected circuit, control module driver fault.
• P0807 — P0807 — Clutch Position Sensor Circuit Low. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: corroded, loose or damaged connector, control module driver fault, blown fuse feeding the circuit.
• P0808 — Clutch Position Sensor Circuit High (P0808): 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 corroded, loose or damaged connector, open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit.
• P0809 — OBD2 code P0809 flags a problem with the sensor and actuator circuits (clutch position sensor circuit intermittent). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit.
• P080A — OBD2 code P080A flags a problem with the sensor and actuator circuits (clutch position not learned). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, open or shorted wiring in the circuit, blown fuse feeding the circuit.
• P080B — Upshift/Skip Shift Solenoid Control Circuit Range/Performance (P080B): a powertrain (engine/transmission) fault affecting the automatic transmission control. Short, gentle driving to a shop is usually possible. Most often caused by faulty transmission speed sensor, valve body wear, failed shift or pressure control solenoid.
• P080C — P080C — Upshift/Skip Shift Solenoid Control Circuit 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, internal mechanical wear (clutches, torque converter).