Vehicle applicability: This diagnostic supplement covers multiple Ford vehicles and engines. Follow the application named in the source below. Some references apply to vehicles other than Mustang.
1-22 Description and Operation
Engine Control Components
Typical EVAP Canister Vent Valve
Evaporative Emission (EVAP) Check Valve
EVAP Check Valve
The EVAP check valve is used on turbocharged engines to prevent boost pressure from forcing open the EVAP purge valve and entering the EVAP system. The valve is open under normal engine vacuum. The valve closes during boost conditions to prevent the fuel tank from being pressurized and hydrocarbons forced out of the EVAP system into the atmosphere through the EVAP canister vent valve. When the engine is OFF, or at atmospheric pressure, the EVAP check valve is in an indeterminate state. The EVAP check valve is an integral part of the EVAP purge valve assembly.
Typical EVAP Check Valve
Item | Part Number | Description |
|---|---|---|
1 | — | EVAP Check Valve |
EVAP Dual Check Valve
The EVAP dual check valve allows purge flow during boost conditions. Fuel vapors flow through the EVAP dual check valve to the intake air system upstream of the turbocharger before entering the intake manifold. When the engine is OFF, or at atmospheric pressure, the EVAP dual check valve is in an indeterminate state.
There are 2 types of EVAP dual check valves on turbocharged engines. One type has the check valves integrated in a single housing assembly. The second type has separate check valves connected to a hose assembly with the EVAP ejector integrated with one of the check valves.
2016 Powertrain Control/Emissions Diagnosis, Gasoline Engines, 3/2015
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.