HVAC Smell... "Afterblow"?

BlancoSilverado · September 20, 2019

Hello Everyone,

I have a 2019 silverado and i heard on the forums the other day and people were talking about having the "afterblow" feature turned on in our trucks. Is there a way for us to do this at home or do i have to take it into the dealer?

Does anyone know the special thing to say to the dealer when i go in to have it turned on. i called a few dealers and one had no idea and another hasn't done it to the new truck yet and might take them several hours.

If anyone has done this, how long did it take for your dealer to have this done.

Any and all appreciation helps.

newdude · September 20, 2019

Dealer unless you can find or know a guy that has a good scanner that can read 2010+up GM cars/trucks. One of those scanners (MAC, Snapon, etc.) might have access to do it. It takes all of 5 minutes to actually do, but they will probably charge a minimum of a 1/2 hour. Its as simple as going into the HVAC control module and turning it on. No programming required at all otherwise.

I've done this on my last two trucks, no unwanted HVAC odors yet. The blower motor runs a few minutes after shutting the truck off to dry out the evaporator core. It can vary the run time based on HVAC demand when the vehicle was running, so the colder the temps set, the longer it may run to dry it out.

Edited September 20, 2019 by newdude

holi gone · September 20, 2019

1 hour ago, BlancoSilverado said:

Hello Everyone,

I have a 2019 silverado and i heard on the forums the other day and people were talking about having the "afterblow" feature turned on in our trucks. Is there a way for us to do this at home or do i have to take it into the dealer?

Does anyone know the special thing to say to the dealer when i go in to have it turned on. i called a few dealers and one had no idea and another hasn't done it to the new truck yet and might take them several hours.

If anyone has done this, how long did it take for your dealer to have this done.

Any and all appreciation helps.

+1

BlancoSilverado · September 25, 2019

Ok so i went to the dealer to have this feature turned on. It took roughly 2-1/2 hours to have this done. They also did some GM anti mold/bacteria spray through the HVAC to get rid of the smell. I will turn it on later today to verify the smell is gone and/or is dissipated. only time will tell if this actually works.

2016 Sierra Owner · September 25, 2019

Is there a cabin filter in these new trucks? Did they change that for you as well?

BlancoSilverado · September 25, 2019

16 minutes ago, 2016 Sierra Owner said:

Is there a cabin filter in these new trucks? Did they change that for you as well?

Good question, i have not verified but i told them not too because i put a Wix Charcoal filter in a month or so ago, thinking that might fix it. The old filter did not smell but i was thinking of charcoal would get rid of the smell.

They did tell me that they removed it to put the GM spray stuff on my coil.

Forgot to mention that i did not smell anything at lunch. Might of found a cure.

Edited September 25, 2019 by BlancoSilverado