OBD-II Trouble Code Description for P0440 GMC

Evaporative Emission System

What does this mean?

OBD2 Code P0440 GM definition:
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.

Symptoms

Possible sumptoms of OBD code P0440 GM
You likely won’t notice any drivability problems.

Causes

Possible causes of OBD code P0440 GM
A code P0440 GM could mean one or more of the following has happened: The gas cap is not installed or working properly The purge solenoid has failed The canister is plugged and not working properly

Possible Solutions

With a P0440 GM OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try: Remove and reinstall the gas cap, clear the code, and drive for a day and see if the codes come back. Inspect the EVAP system for cuts/holes in tubes/hoses Inspect for damaged or disconnected hoses around the Evap purge solenoid Check and/or replace the sensor Check and/or replace the purge valve Have a professional use a smoke machine to detect leaks

Related Codes

P0441 GM P0442 GM P0443 GM P0446 GM P0453 GM P0455 GM P0456 GM