Evaporative Emission Control System Malfunction
This trouble code indicates that the evaporative emission control (EVAP) system is not functioning properly. The EVAP system is designed to prevent fuel vapors from escaping into the atmosphere. When the engine is not running, the EVAP system stores fuel vapors in a charcoal canister. When the engine is running, the fuel vapors are drawn into the engine and burned.
There are several possible causes for trouble code P0440, including:
- Faulty evaporative emission control system purge valve
- Faulty gas cap
- Leaking fuel tank or fuel lines
- Faulty charcoal canister
- Damaged or disconnected vacuum hoses
- Faulty pressure sensor or switch
If you are experiencing trouble code P0440, it is important to have the vehicle diagnosed by a qualified technician to determine the cause and make the necessary repairs.
Here are some additional symptoms that may accompany trouble code P0440:
- Check Engine Light is illuminated
- Strong fuel odor
- Poor fuel economy
- Engine stalling or rough idle
- Difficulty starting the engine
