P0443: Canister bleed electrovalve control open circuit

[gwest]

On my 2007 Peugeot 207 CC 1.6 VTi automatic (VIN: VF3**************[VIN obfuscated, can be read by forum staff]) I have a fault code P0443: Canister bleed electrovalve control open circuit. The only reason I scanned the vehicle (Launch 123E scanner) was because I was checking for any automatic transmission fault codes I might have. On the change from 1st to 2nd I often get a thump, going up a slope occasionally several thumps. This is a vehicle that I have no previous history on- I bought it as a non-runner and put in a replacement engine. It had covered 131,000 km and almost certainly had not had the transmission fluid drained. When I got it back on the road I was alarmed at the transmission whine, in all gears and worse on over-run. I have now drained it again after 1000 km and the whine is improving and occasionally the 1st to 2nd change is fine.
No transmission fault codes were present but there was the one for the purge valve. And I did read that on some vehicles problems with the purge valve can affect the auto transmission gear change. Of course not necessarily the same fault code as mine. I can imagine that a purge valve that is stuck open might be equivalent to a vacuum leak?
The accessibility of the valve is appalling, and the normal tests of electrical continuity and applying 12V would be very difficult. I have a spare purge valve and when I tested it on the bench it had 32 Ohms across the two pins, but did not respond when I applied 12V ( I was expecting to hear a click).

Can anyone enlighten me on how to test these units, part number V754196180?

[gwest]

Not sure what I did wrong the first time but when I retried applying 12V to my spare bleed valve there were sparks and noises. And the vacuum that I had applied to the engine end of the bleed valve disappeared. So it looks like I have a viable spare. What is not so clear is what is wrong with the one on the car. I also have a spare engine wiring loom and I was able to trace the no. 1 white wire on the bleed valve connector to pin 6, and the no. 2 orange wire to pin 17 on the middle 53 pin multi-connector on the engine ECU.
I cleared the fault code but it came back after an hours driving.

[gwest]

Well, access to the evap bleeder valve wasn't as bad as I thought and I managed to remove mine. It tested fine- 32.5 Ohms and it responded to 12V. With the ignition on I had 3.5V on the no. 1 connector pin ( the other cable on the multi-meter was to a body earth). And when I checked the resistance of the wires running from pins 6 and 17 on the ECU middle connector block to the purge valve connector it was zero. Now I am concerned that the fault may be with the ECU? Any suggestions would be most welcome.
It is also possible that my Launch diagnostic tool might not be completely accurate, and I understand that in addition to the bleed solenoid on the engine there is a vent solenoid for the charcoal cannister that forms part of the system for the ECU fault diagnosis routine. It looks like this is integral with the charcoal cannister so I will investigate.

[gwest]

Well, no signs of a vent solenoid at the charcoal canister, so I just fitted my spare bleed/purge solenoid in case it made any difference. As I was struggling to get the wires connected to it I realised that the connector did not click into place. I practised on the spare loom I had and that went in with an audible click. The female connector on the loom looked alright, so I filed a few places on the body of the connector on the solenoid, and while it didn't click, it didn't seem to pull off either. I have driven the car sufficiently that if the fault remained it should have showed up again, but so far so good. If it really is the problem it just shows that it is the small things that often get you. And it gave me a bit more faith in my Launch diagnostic tool that it may have correctly located the fault.