P0440 - EVAPORATIVE EMISSION CONTROL SYSTEM FAILURE
POST UPDATED IN January, 2023
Description of DTC code P0440 Generic
When the diagnostic code P0440 OBD2 is set, it indicates that there is a fault in the EVAP (The evaporative emission control system) system, i.e. one of its components is not working properly. Parts of the Evaporative Emission Control System (EVAP) include the gas blanket, fuel lines, purge valve, carbon filter, and other hoses.
The function of the EVAP system is to prevent the escape of fuel vapors from the vehicle’s fuel system. The fuel vapors are routed through hoses to an activated carbon filter, which stores them so that when the engine is running, a purge control valve opens, allowing an intake vacuum and diverting the fuel vapors into the engine.
Symptoms of fault code P0440 Generic
The Engine Check Engine light is illuminated and the code is set in the Engine Control Module (ECM) memory.
You can smell fuel vapor in the vehicle or even around it.
Causes of OBD2 P0440 Generic
The problems that lead to the establishment of Fault Code P0440 may be:
The fuel cap is not properly fitted, it is not working properly.
The fuel filler pipe may be in bad condition.
The purge solenoid may be defective.
An EVAP system hose may be punctured.
Damaged carbon cartridge.
Defective fuel tank.
Possible solutions of the DTC code P0440 Generic
To solve the DTC P0440, you can do the following:
You can remove and reinstall the fuel cap. Then you delete the code and see if it is displayed again.
Check the EVAP (Evaporative Emission Control System) system for holes in one of the pipes or hoses. Repair or replace it if necessary.
There may be defective or disconnected hoses around the bleed solenoid, repair them.
Check the EVAP system for leaks, using a professional smoke machine to detect leaks.
You can check the operation of the FTP sensor (Fuel Tank Pressure Sensor). Change it if necessary.