My 2015 GMC 2500HD Denali does this, also. My father's 2015 Silverado Z71 does this, also.
My previous 2008 Ford F-150 did NOT do this. My father's previous 2002 Silverado did NOT do this. My mother's old Chevy Impala did NOT do this.
This is ABSOLUTELY a design flaw on Chevy / GMC's part and they need to fix it. This is something that would make me never purchase a GM product again. I have had the fumes in the cab get so strong, while waiting in traffic, that i've felt light-headed at times. This is just completely unacceptable. Recirc should, as the Owner's Manual says, prevent outside odors from entering the vehicle. At the very least, GM should honor their own printed words.
GM needs to fix this immediately.
