Talon90 will most likely have to answer this. I am wondering if the afterblow is already enabled on the C7. For those who don't know, the afterblow keeps the AC from becoming smelly by turning on a fan after the engine is stopped if certain time & temperature conditions are met.

On the C6, it had to be specifically enabled. I'm hoping it's already enabled on the C7. If not, I'll have my dealer do so before I get it.

If it's not already enabled, what are the instructions for doing so?

I never knew that and my c6 stunk like an afterblow (Fart, skunk)

si says available if reprogrammed by tech
Afterblow

Afterblow is a feature that dries the evaporator core by operating the blower motor after the engine is turned OFF. This reduces the amount of microbial growth that can create undesirable odors. The vehicle does not come equipped with the afterblow feature turned ON. If the afterblow feature is required due to an odor concern, it must be enabled using the scan tool Afterblow configuration function.


After the HVAC control module has been programmed for afterblow, the following conditions must be met for afterblow to operate:

•The engine has been turned OFF for at least 30 minutes.
•The ambient air temperature is at least 21°C (70°F).
•The A/C compressor operated for more than 2 minutes before shut down.
•The system voltage is at least 12 volts.
Once the above conditions have been met, the following sequence of events will occur:

 1. The blower motor will RUN for 20 seconds.
 2. The blower motor will be OFF for 10 minutes.
 3. The blower motor will RUN for and additional 20 seconds.

The temptation to contribute to a 'Afterblow' Thread is nearly unbearable . . .

This is for the C7? If so, I think it's exactly like the C6.

Sorry michaelinmech, I don't have the restraint... I thought afterblow was what I got after taking my wife out to a really nice dinner.

I'm curious to know how GM plumbed the condensate drain in the C7. In the C6, it would back up, causing the nasty smells.

Is it still directly over the right downpipe? Do the cars make a sizzle-sizzle-sizzle noise when you park on a hot day?

yes CM is for C7

I got a big pot of chilli that will install some afterblow for ya!

Sorry, couldn't resist.

On a serious note...
Will be interesting to see how this feature if available is implemented and enabled. Does sound like a good idea but would think it would need more than 40 seconds to dry off the evaporator.
Sure would beat turning the HVAC to vent and running the car for a bit before shutting it down for the night.

Following up on this: the after blow is not enabled by default, but there is a procedure to do so. My dealer, Ken Fichtner, was nice enough to research it and enable it for me before delivery. No stinky A/C for me.

I had Afterblow enabled on my 2014 Stingray today. I learned of the feature by listening to a radio talk show hosted by a GM Master Technician. I searched the Forum for discussion about the feature and this thread is all I could find. Since it had not been discussed in nearly three years, I thought it useful to bring to the surface once again, especially for those who live in areas to the South.

Good info.

Why would talon90 most likely have to answer your question? He is not employed by GM(never has been) and is not a degreed engineer.

Excellent information! Thanks for bringing this to my attention!

On all my cars for many years I have dried out the evaporator by simply turning off A/C for my last minute of driving (leaving the blower on high) before putting the car away. Totally prevents the odor problem.

I don't understand why this has to be enabled by a tech at the dealership. If it is available at all, why wouldn't it be a user-selectable option? How any more "features" are on the car that we don't now about? Seems strange to treat this stuff in that manner.

I agree, and it is on all GM vehicles.

+1

Its become second nature for me to turn off the A/C for the last 30 seconds of driving before I get home. Works perfectly.

Would that be considered pre-blow?

I had afterblow enabled by my dealer. The service lady looked at my cross-eyed when I was explaining it to her. But the techs knew about it.

How do I know they did it. Do I wait 30 minutes and go check on the car to see if the fan turns on? Maybe put a little piece of paper in the vent to see if it blows out?