Curious noises.

[Kirk Thompson]

When I hit the unlock button or insert the key I hear what sounds like electric pump whirring noise under hood and in dash.
It starts out as a steady whirring then steps down as if auto-pumping a tire or something.
What the heck is that?
Some of that California emissions crap or what?

 

[ygmn]

what model do you have LT? does it have air suspension?

 

[Vaeagleav]

If you have an LTZ model AV it is probably the pump for the air suspension. Otherwise it could be the navigation disc in dash starting up if you have that feature......

 

[gmAtech]

in the dash has to be either the CD changer or an HVAC actuator