2021 Sierra AT4 - heated mirrors?

[GullLakeMi]

Window sticker on my truck says it should have heated mirrors.  Now that weather is turning, I am questioning whether it actually does.  I don't see the marking on the actual side mirror and don't see the results with defrost running.  Wondering if this is a chip supply chain issue surprise.  Haven't had a vehicle in at least 20 years without that feature.

 

Can anyone who has this feature confirm whether there is a marking on the mirror itself?  How else could I confirm since it is not clearing moisture quickly?

[redwngr]

They should come on with the rear window defroster. (button labelled 'rear', at the 7 o'clock position)

 

I'm not aware of any markings on mirrors (but also not sure that there isn't a way to tell)

 

As you are aware, heated mirrors are standard on most trims (available, but not standard on Base sierra and on WT)

 

On tow mirrors, only the upper glass is heated. 

 

 

 

 

 

If you have a temp gun it might be able to help diagnose.

Edited November 1, 2021 by redwngr

[Adamace1]

Yea you have to hit the rear defrost button. Turning your climate control to dash/ windshield vents will not turn on heated mirrors.

Edited November 1, 2021 by Adamace1

[BlancoSilverado]

For my truck;

RPO: DLF

" MIRRORS, OUTSIDE HEATED POWER-ADJUSTABLE"

Manual states that you have to turn on the rear defrost to have them turn on. Unless you do not have a rear defroster. 

 

 

[redwngr]

OP's '21 AT4 should have both.

[newdude]

Heated mirrors were not on the chip chopping block.

 

They come on when you turn on the rear window defogger.  On the same button.    

Edited November 1, 2021 by newdude

[GullLakeMi]

Thanks for the replies.  I did check the manual and understand aligned with rear defrost.  Maybe they are just not as responsive as I remember on my previous truck/vehicles.  Cold weather season is coming!  I'll get more tests soon.

[JimCost2014]

2 hours ago, GullLakeMi said:

Thanks for the replies.  I did check the manual and understand aligned with rear defrost.  Maybe they are just not as responsive as I remember on my previous truck/vehicles.  Cold weather season is coming!  I'll get more tests soon.

The Layman's way to test (have done it myself), is to turn them on when it starts getting cooler in the evening, early morning, and just breath on them. If they are working, you will see steam on the glass, then it should start to disappear from the heat generated by the mirror.