I've been battling this chirping in my serpentine belt for a couple of years now. It can be difficult to reproduce so my dealer hasn't been able to permanently fix it after a couple of belt replacements and even a tensioner replacement.
It seems to come and go, maybe based on the weather and how much I've driven the car that day/week, but hard to pinpoint the variables exactly. As demonstrated in the video linked above it goes away for a few minutes when I squirt water on the belt.

Last night I took the belt off and gave the belt and the pullies a good cleaning. It still was happening this morning. Any other ideas? I can't really bring it back to the dealership without something more specific and reproducible because I'm getting charged for the ESP diagnostic deductible now.

 

Sounds like the beginning of a jazz song

 

Let’s get this chirping issue escalated for you, Zathu. Please PM me with your VIN, dealer, mileage, full name, and best daytime number.

Deysha