HVAC TSB update issues

[ShadowsPapa]

Jay and company can move this if it needs to be in a better place, but I didn't see "HVAC" or AC or heater specifically mentioned in any heading.........

Anyway, my truck had been pretty well behaved as far as the HVAC. Yes, I DID experience the "hot humid air coming out of the right side" on about 3 different occasions. On the long trips to and back from Colorado Springs when it was hot and the AC was running in auto mode for hours on end, I did actually for the first time note the warm air coming in for a few seconds. (my wife was driving so I was able to detect it easily from the right seat)
And later in a couple of other long trips (over 1 hour one way) I noted the same thing - HVAC in auto mode, temp set to about 69 or 70, hot air for a few seconds then back to AC.

I figured what the heck - it wasn't a big deal, only just mildly annoying, especially since it never ever did it on any trip under 1 hour and even on long trips it went easily 45 to 60 minutes between cycles, but I read the TSB and it said it solved that plus made other enhancements. So last time in to the dealer, I handed them the TSB and said I had noticed the hot air cycle thing.
They did the update.
BIG MISTAKE.
Now with winter coming on and cold temps in the 50s and 60s, the HVAC in auto mode is just not usable.

Outside temp was about 55-60 driving back from Davenport at 2am last Saturday my wife was driving and she had her side set to 70 as was mine. It was still cold in there so she bumped hers to 72 to try to warm it up - my side blew COLD AIR out the dash vents. I don't mean cool as in 70 degree air, I mean more like 60 degree air. It was cold. I felt the air coming out her side and it was warm. So I bumped mine to 72 and it got a bit warmer in there but not great.
It used to be that set to 70 degrees in auto mode that truck cabin warmed up in minutes. Now it never warms up to temp and it blows cold air out for as long as you are driving never reaching temp.
So I tried something - I took it out of auto mode, temp still set to 70 both sides - and warm air came out. We set it to "Feet only" and it warmed up in that cabin in minutes and then maintained a good temperature.
I moved it back to auto - COLD air blasting out the dash vents. Back to manual - warm air, auto - cold air.
So the fix literally broke auto mode on the truck.

It's literally so bad auto mode is totally useless unusable. That sucks as from the time I bought that truck I set it up to auto, 70 degrees and that's where it's been year-round since November 2019 when I drove it home. The only times anything was ever changed was when my wife set the temps up or down just a bit - like maybe down to 68 if she was feeling too hot, or up to 71 if she was chilly, otherwise, it was always in auto, it warmed up or cooled down super fast (normally within a mile!).
Now auto mode is COLD AIR coming out the dash vents all the time - and the air speed never decreases. it's like the fan is stuck on medium and the air temp at about 65 most of the time unless you really bump the tmps up and have both sides set exactly the same. That's the only time the air coming out is warm.
Auto mode the fan runs high until the temp is reached then it ramps down to low - not now, it stays blowing out at about a medium speed.

Has anyone else had their HVAC "flashed" via the TSB?
What were the results?
Mine is useless now in auto. I am going to see if there's any way to revert back a rev.
The update literally broke mine.

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[JAVIERGONZO]

I was going too. But haven't done it. But my auto mode acts like yours even without the TSB. I think auto mode genuinely just sucks. The algorithm the electronics use is just way off. Sounds like I should stay away from the TSB after your experience though.

 

[ShadowsPapa]

I was going too. But haven't done it. But my auto mode acts like yours even without the TSB. I think auto mode genuinely just sucks. The algorithm the electronics use is just way off. Sounds like I should stay away from the TSB after your experience though.

Mine used to work PERFECTLY in auto mode. That's why it was always in auto mode.
I set the temp I want and it simply did it - and did it fast. It was never ever too hot or too cold in that truck. If it was 50 degrees out but a SUNNY day so it got to 75-80 inside the truck, it used to cool it down inside then switch to heat to keep it there on those chilly sunny days.
I could take off on a 20 degree day and in a mile that cabin was warmed up to 70 (or 68 or whatever) and the fan slowed down and it maintained that temp.
If it was 95 out, by the end of a mile it was cooled down to my temp setting and the fan slowed down and it kept it at that temp.
It was the best working auto mode HVAC I'd ever had (save for the infrequent hot air cycles on long trips)
Now it sucks - all auto does is blow cold air, fan on medium, unless you jack the temp up. We can't even use auto mode unless we want cold air blowing on us for the whole trip.

I have to find time to get the truck back to them ASAP with winter coming on fast here.

I'm hoping someone who has had the TSB done will chime in - or maybe this is a warning - beware of what MIGHT happen with the TSB.
So far no one is talking about it so maybe mine is a fluke.
Should have left well enough alone - it was near perfect.

 

[LaterGator]

I had the TSB done, and didn't notice much difference. It did fix the hot air problem. But I rarely run it in auto mode down here because I like driving with the windows down.

 

[ShadowsPapa]

I had the TSB done, and didn't notice much difference. It did fix the hot air problem. But I rarely run it in auto mode down here because I like driving with the windows down.

Glad to hear it at least fixed the hot air thing............. will be interesting to see what the dealer says when I tell them of how bad it's made things.

 

[Renegade]

I use auto mode almost exclusively. Every once in a while the temp of the air coming out gets out of whack for a little bit. I think it may be a faulty cabin air temp sensor.

 

[ShadowsPapa]

I use auto mode almost exclusively. Every once in a while the temp of the air coming out gets out of whack for a little bit. I think it may be a faulty cabin air temp sensor.

Seems to me there was a TSB about a faulty connection - maybe that's related to what you see? (or the sensor like you said)

Mine worked perfectly until the TSB was applied (perfectly except for the rare hot air thing)

 

[BAT]

Mine used to work PERFECTLY in auto mode. That's why it was always in auto mode.
I set the temp I want and it simply did it - and did it fast. It was never ever too hot or too cold in that truck. If it was 50 degrees out but a SUNNY day so it got to 75-80 inside the truck, it used to cool it down inside then switch to heat to keep it there on those chilly sunny days.
I could take off on a 20 degree day and in a mile that cabin was warmed up to 70 (or 68 or whatever) and the fan slowed down and it maintained that temp.
If it was 95 out, by the end of a mile it was cooled down to my temp setting and the fan slowed down and it kept it at that temp.
It was the best working auto mode HVAC I'd ever had (save for the infrequent hot air cycles on long trips)
Now it sucks - all auto does is blow cold air, fan on medium, unless you jack the temp up. We can't even use auto mode unless we want cold air blowing on us for the whole trip.

I have to find time to get the truck back to them ASAP with winter coming on fast here.

I'm hoping someone who has had the TSB done will chime in - or maybe this is a warning - beware of what MIGHT happen with the TSB.
So far no one is talking about it so maybe mine is a fluke.
Should have left well enough alone - it was near perfect.

That is how mine is. I keep it set on Auto around 70 and its been perfect. During the winter if I switch to manual heat it just blows superheated air so hot its crazy. So I leave it in Auto and have had no issues other than my wife when she drives it she immediately starts screwing with all my settings even though has been told to leave it alone. Then she complains when its not doing what she wants. I do get he occasional warm air thing but hasn't been big deal and I don't want them to mess up my HVAC

 

[The Bean]

I took mine in for regular maintenance and I noticed they had done about 5 or 6 TSBs, one of which was the a/c. That was back in August, and I haven’t had any more issues since then, either with the hot air blowing back in, or issues with the auto mode being weird. It works as well now as it did on day one. I leave it on auto almost every time I drive it, unless it’s super nice out and I have the windows down (weather changes fast in Florida!). Hopefully the dealer can get your issues sorted out!

Edit: I keep my a/c set at 72.

 

[ShadowsPapa]

I took mine in for regular maintenance and I noticed they had done about 5 or 6 TSBs, one of which was the a/c. That was back in August, and I haven’t had any more issues since then, either with the hot air blowing back in, or issues with the auto mode being weird. It works as well now as it did on day one. I leave it on auto almost every time I drive it, unless it’s super nice out and I have the windows down (weather changes fast in Florida!). Hopefully the dealer can get your issues sorted out!

It helps knowing that the TSB has been applied to others and worked out fine.......... so either mine went bad or there's another issue at play here.
We don't like cold air blowing at us out the dash at medium fan speed - I guess we're weird, HA.
They'll have the history, I'll explain the problem, let them sort it out.

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