Evaporative Emission Control System: Description: Notes

Evaporative Emission Control System prevents fuel vapor stored in fuel tank from vaporizing into the atmosphere. When the fuel evaporates in the fuel tank, the vapor passes through vent hoses or tubes to the canister filled with charcoal and the canister temporarily holds the vapor in the charcoal. The ECM determines when to draw the gathered vapor into the combustion chamber during certain operating conditions by using engine vacuum.