The P0440 code copes with the evaporative system circuit which moderates emission produced by escaping fuel fumes in the petrol tank. This electrical circuit comprises of all the vacuum hoses located at storage tank including every components employed to capture the gas fumes such as: the canister container utilized to stack away gas vapor; solenoids and valves which are employed to open/shut the stream of gas vapor between the canister and throttle body; the computer which control all of these components and ultimately the wirings between all these evaporative parts.

When this P0440 code begins flashing in the instrument panel, it could mean the following: the gas cap is not properly seated, one of the evaporative solenoids failed to function or the canister itself is faulty, a failure in other parts like leaky vacuum hoses, bad gas after you changed petrol station or faulty computer module.

To fix this P0440 code, always check the gas cap first since it accounts to almost 90% of the problem. If the vehicle has a lot of miles, you are better off changing the gas cap. Should the code remains, get hold of a vacuum diagram so you can trace and check out all the affected parts. Further more, look for the apparent common problem like signs of gas leak which can be seen visually or by using your sense of smell.

More Tip on P0440 Code:

Any wetness seen on the sides of the canister implies a gas leak which need a closer inspection. The same can be said about seeping vacuum hoses and solenoids. Worse come to worse, always follow the wiring diagram circuit of the evaporative system to make sure all the components and solenoids are properly grounded at the right location.

Quick note on P0440 code repair:

Make sure to check ATS for the most common fixes for this trouble code for your particular vehicle before attempting to fix it. Sometimes,it’s just a matter of replacing or cleaning a simple part. Don’t waste your time and money.

Have fun!