Need to find the Air duct temp sensor on a 2002 with Auto climate controls

Anyone know where the Duct temp sensor is on a 2002 2500 Avalanche with the auto climate control?

I don't know where a sensor is inside the air ducts but most AVs have a temp sensor in the headliner right above the driver's head and looks like a round disc with holes in it. Most new owners think it's a speaker for OnStar but it's not. Sometimes it makes a squeaking noise and needs replacement.

Remove the radio.
Disconnect the electrical connector from the upper duct air temperature sensor.
Remove the upper duct air temperature sensor from the air duct by prying out of the duct.

Awesome!  That's what I needed!