Boost Control Solenoid Test

[Edhertz]

Regarding the two three port boost control solenoid control valves. Do they operate as binary on /off or are they pwm? I am using a hand held vacuum tester connected to the vacuum port and holding my finger on the function port. When I pump hard the needle goes to half way and quickly returns to zero with a buzzing sound from the exhaust port. Is this normal?
Thanks for replies in advance

[wheeler]

They use OCR control which im guessing is the same thing as PWM? It changes the duration that the valve opens & closes to give a kind of in between on & off.

[Edhertz]

Thanks for reply. Ive checked the function of the solenoids in situ with the engine running and the guage shows a good vacuum which
collapses in response to a signal from the ECU on both. This behaviour suggests that the device being controlled is either open or closed and not
positional as with PWM. In terms of red herrings this could be one, as I was only able to test both on the EGR connection. The signal to the Wastegate solenoid
seems to be fixed and holds the vacuum at half guage despite rev changes so there's a problem there. I hope this is making some sort of sense. Next step is to find out why the ECU is not talking to the Wastegate ..... MAP sensor?