EJ8 P1457 Testing the CSV from the PCM?

[Quinnstont]

Hello everyone, I have had the P1457 code for a good while and recently started to look into it.
2000 Civic si (Canada) D16Y8 M/T EJ8
I followed the service manuals instructions on diagnosing the issue, and ended up with "Replace Canister Vent Valve" because the CSV did not shift or hold vacuum when i turned the ignition to on, and grounded PCM terminal A4. (Evap Control Canister Vent Valve) Should grounding this terminal cause the valve to shut? I applied 12v to the solenoid and it shifted and sealed fine so im having a hard time believing there is something wrong with it. I checked continuity from terminals A4 and B2 (PG1) to the 2P connector at the CSV and there seems to be no shorts, and there is 12v present between A4 and B2 when the 2P connector is attached to the CSV and the ignition "ON" I dont really wish to buy a new CSV if my problems are elsewhere.
So i guess im wondering if all this is right? Should grounding said terminal cause the valve to shut? What other things might be wrong? Thanks in advance.

 

[Quinnstont]

Here is some information i collected this morning. I hope maybe this will help:
11.4v from the black wire at the 2P to body ground
9.9v from the black wire to the green wire at the 2P with terminal A4 grounded
11.3v from B2 to A4 with solenoid plugged into the 2P
26.5Ω across solenoid contacts
32Ω from B2 to A4 with the solenoid plugged into the 2P
5.7Ω from the black wire at the 2P to body ground?

Also, ive tried attaching a different CSV the 2P and grounded terminal A4, no luck.

 

[Quinnstont]

Turns out that using a probe tester to ground out the pcm draws too much power for the solenoid to operate. Tried it with a wire and it works okay. Reinstalled it. While testing, I found that the purge solenoid is not opening when it should be. (engine warm and in 1st gear) so I shorted it at the pcm and it works fine. When should it be opening? When I tested the 2P I get 12v all the time, but the valve remains closed. Any ideas?

 

[Quinnstont]

Okay:
Check the EVAP control canister vent shut valve:
Does the valve hold vacuum?
No

Check the EVAP control canister vent shut valve (by grounding pcm)
Does the valve hold vacuum?
After some struggling, Yes

Check the vacuum when cold:
Is there vacuum?
No

Check the vacuum when hot:
Is there vacuum?
No

Check the EVAP purge control solenoid valve:
Is there battery voltage?
Yes

Inspect vacuum hose routing. If OK, replace EVAP purge control solenoid valve.

My only issue with this is that the valve shifts fine when I ground it at the pcm. I tested both hoses on either side of the valve for blockage, and they were clear.

 

[Quinnstont]

Also, are these the right conditions for the purge valve to open?

Warmed up to when the rad fan comes on, and in 1st gear?

 

[Quinnstont]

I apologise if I was unclear, my initial problem was with the vent valve, not getting it to actuate via grounding the pcm, but I have since figured that out and confirmed that I was working properly. I then followed the flow chart to where the purge valve ought to be opening when the engine is hot etc. The purge valve is not opening with these circumstances, however it opens just fine when grounding the pcm. Sorry for the confusion

 

[Quinnstont]

A6 I believe it was