'01 tahoe "speaker" on headliner ??
 

Ok what is the small round "speaker" in the headliner above the driver's head for? Mine makes a fairly loud growling sound as soon as you turn the ignition key to "on" and doesn't stop until you turn the key "off", no other sounds come from it. Is it part of Onstar? Anybody else experience this? How do I make this thing shut up?

Re: '01 tahoe "speaker" on headliner ??
 

It is the temp sensor for the automatic climate control. If it is noisey it needs replaced. It has a small fan in it to sample the cabin air temp.

Re: '01 tahoe "speaker" on headliner ??
 

Fantastic! I had no idea what that thing was, thanks! In case someone in the future searches and finds this, I did some research and the GM part number is 25771194 and it's called an aspirator....$30 part through gmpartsdirect.com.

Re: '01 tahoe "speaker" on headliner ??
 

Thanks for the info. Ive got an 03 Z71 Tahoe and both the one above the drivers head and the one above where the third row seat would be buzz real loud first thing after start up. I thought it was part of OnStar as well and was going to remove them completely since I do not use OnStar.