Fuel Tank: Operation: Notes

All models pass a full 360 degree rollover test without fuel leakage. To accomplish this, fuel and vapor flow controls are required for all fuel tank connections.

All models are equipped with either one or two check valves mounted into the top of the fuel tank (or pump module).

An evaporation control system is connected to the check valve(s)/control valve to reduce emissions of fuel vapors into the atmosphere, when the tank is vented due to vapor expansion in the tank. See EMISSIONS CONTROL article. When fuel evaporates from the fuel tank, vapors pass through vent hoses or tubes to a charcoal canister where they are temporarily held. When the engine is running, the vapors are drawn into the intake manifold. In addition, fuel vapors produced during vehicle refueling are allowed to pass through the vent hoses/tubes to the charcoal canister(s) for temporary storage (prior to being drawn into the intake manifold). All models are equipped with a self-diagnosing system using a Leak Detection Pump (LDP) or Natural Vacuum Leak Detection (NVLD).