Beeping noise under hood

[EM1]

Hey all,

2015 Silverado HD. I've got a beep or a "fax machine tone" coming from the engine compartment when the truck is off. Sometimes I'll hear it when I'm near the truck so I will try to find it and of course it stops when I get close. Any ideas?

[TheWoodsman]

If your truck is still stock (no emissions deletes etc.) it's your EGR module running a self-clean process after every shutdown. ?

[EM1]

Yep. All stock. Thank you. Even hours after the engine has been shut off?

[CAtaylor]

Not for hours. Not sure what that could be

[Lsummers]

I have the same thing happening.  An hour after I'm home it starts chirping/beeping for 10 minutes and stops.  Then starts again.

[Colossus]

Communicating your driving information to OnStar. 

[Colossus]

Well, not really.  I think..

[Lsummers]

Thanks, I think