All,
Just looking at the wiring diagram there's not much to it. The ECU get a signal that there is a build up of pressure in the tank. The ECU sends 12 volts to the canister Causing it to close. (INCORRECT: shut off valve causing it to open) The Purge control valve
gets a signal and will scavenge off the excess vapor by pulsating and allowing engine vacuum to burn off the vapors. Then there is the fuel filter There is a check valve or a mechanical device inside that is part of the EVAP circuit. I plan on an autopsy
as soon as the new one arrives. I need to know its function. I have a Leak tester / smoke machine that I will connect as soon as I am sure everything is assembled correctly to check for any leaks.
It seems to me that its a mechanical malfunction and not electrical. I've been wrong before.