Hi Folks. I'm driving across the country in my 2022 GLS 450 and yesterday I drove from St. Louis to Atlanta. Unfortunately, along the way I could not get my AC to put out any cold air. I mean it was hotter in the car than outside. No matter how I set the HVAC switches, no cold air would come out. I restarted the car a few times and that didn't help. Needless to say it was a hot and loud drive as we drove 600 miles with the windows partly open.

So I made an appointment with the local MB dealer here in Atlanta, and of course when I started the car this AM to drive it there the AC worked just fine! The dealer also ran checks on the AC and reports that nothing was wrong. Can anyone shed some light on what the problem might be? I swear that I had the AC switches set correctly and this is not operator error!! Thanks for any advice.

 

Verify the rear seat settings. I had a similar situation and it was because somehow the 3rd row was set to 60 or low and was demanding all of the cold air. Apparently the AC is set to prioritize the rear to keep temp. Seems odd. The service writer mentioned to me that sometimes the "case" goes bad. When I pried to find out if he meant blend doors or something else and he just said they have to replace the entire case because it goes bad. I hope they can get it resolved for you, Mine has never done it again so I cannot say for certain mine is "fixed"

 

Definitely check your other vents to see if cold air is blowing elsewhere, if so it's a stuck blend door actuator.

 

"Sync temp" is your friend! Be thankful it's still a physical button....for now!

 

No kidding, BMW X5 and RR just removed them in 2024 models.

 

Yes, this. Literally discovered it after driving our GLS home from the dealer with the air blowing full but not getting cooler. Front was calling for 70 and the rear for 78.

 

we have the same problem did you get a resolution?

 

Nothing was done to make any repairs and the issue has never returned. I think that maybe the rear temp was set very high due to inadvertent contact with the buttons, and this was the sole (silly) cause.

 

Well, that'll do it!
Thanks for responding.