Will the Check Engine Light Come On If the Charcoal Canister Purge Valve Fails?
2 Answers
If the charcoal canister purge valve fails, the check engine light will illuminate. The primary function of the charcoal canister is to adsorb and filter gasoline vapors from the fuel tank. The purge valve controls the entry of these fuel vapors into the engine for combustion, thereby reducing fuel consumption and preventing excessive pressure in the fuel tank. Symptoms of a faulty charcoal canister purge valve include engine hesitation during acceleration and a strong gasoline odor inside the vehicle. In such cases, it is crucial to inspect the charcoal canister system's hoses for cracks. If the hoses are cracked, gasoline vapors may escape directly into the atmosphere, causing the noticeable gasoline smell inside the car. Additionally, if there is a fuel leak in the hoses, air instead of fuel vapors may enter the engine's intake manifold, leading to an overly lean air-fuel mixture. This condition can result in intermittent engine hesitation.
Last time I was repairing a car, a young guy's vehicle had the check engine light on. I hooked up the diagnostic computer and found it was an issue with the evaporative system. Upon checking, it turned out the charcoal canister purge valve was faulty. This part controls the fuel vapor from the gas tank, and if it fails, the check engine light will definitely come on. Nowadays, cars are equipped with OBD diagnostics, and any issues like the valve sticking, leaking, or wiring problems will trigger the computer to alert. I usually tell the owner that besides the light, they might also smell gasoline or have difficulty with cold starts, especially in winter. This part isn’t expensive but should be replaced promptly, otherwise it can affect fuel efficiency and damage the catalytic converter. A roadside shop can fix it in about half an hour, so don’t delay and avoid long trips with it unresolved.
