2022 Z71 Suburban buzzing noise

[Rairai21]

I just got a 2022 z71 suburban and noticed that every time I unlocked it it makes a buzzing type sound that comes from the under carriage. It does it about three times then stops. Anyone know what that sound is? Also another question I want to add running boards, anyone have suggestions on which ones and where is best to buy them. Thank you!

 

[zora]

Vehicles with computers have systems that go to sleep after a period of time. When you unlock the vehicle the systems become active and make a noise for a few seconds. Assume that's what you hear.