Icv should not buzz at all. It's a valve that flips open or closed to let in or block air into the intake manifold. When you apply 12v you should hear the clunk of it opening (and no noise as it stays open) and as you remove the charge it should spring back closed.

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth