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Diagnostic Trouble Code
P0440

Evaporative Emission Control System Malfunction

Technical Description P0440

Evaporative Emission Control System Malfunction

What Does This Mean P0440?

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model.

This indicates that a part of the EVAP control system is no longer fuctioning correctly. The EVAP system consists of many parts, including (but not limited to) the gas cap, fuel lines, carbon canister, purge valve, and other hoses

The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.

Possible Causes P0440

1 The gas cap is not installed or working properly
2 The purge solenoid has failed
3 The canister is plugged and not working properly

Solutions & Repair Steps P0440

With a P0440 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try: