So I ordered a power probe, and plan to test the drain valve and the pressure control solenoid with it, I tried connecting the green tester connector under the drivers side dash, but with fuel pump and everything going off could not tell if the drain valve and pressure solenoid were actually working.
I did find something interesting, there is a wire that is soldered into the charcoal canister drain valve wiring and it runs all the way to the ecm where it is soldered into another wire.
I followed this post on nasioc https://forums.nasioc.com/forums/showthread.php?t=2310341
to repair my corroded wires to the charcoal canister.
the 1st and 2nd pic at position 3 (from above post) below shows where 2 yellow green wires are, these get soldered together, and then to the connector on the evap canister. Also from this post, it indicates the second yellow green provides power to the fuel tank pressure solenoid.
I did not see that 2nd green yellow wire when i stripped back the wiring harness on my car.
On my car previous owner or mechanic has put a red/black wire that was connected here (at wires to connector on evap canister) and runs as I mentioned to the wiring harness at the ECM where it is soldered into another wire (3rd/ pic shows the black red wire going into wires at evap canister, 4th pic at ecm harness)
Anyone know why they may have placed that wire? should my 06 Forester have the second green yellow wire from this connection to the tank pressure solenoid?
I also pulled up back passenger side seat to see wiring harness under there and everything looks good, no corrosion, etc.
So planning to bench test drain valve and fuel tank pressure solenoid with power probe, also thinking of disabling/removing the added red/black wire to see what happens. a
let me know if you have any other thoughts