I posted this on another forum today, but I think it applies to this thread.
The latest dual zone automatic climate control setup for the 2018 model Accord is very frustrating for me, but I don't see much chatter about it on the internet.
Does anyone else have a very difficult time setting a temperature in this car and forgetting it, no matter the temperature outside the car? At this point, I wish I could pull out the system and replace it with a "dumb" panel with two sliders. One would be fan speed and the other would be red/blue temperature selection. With that setup, at least I wouldn't have to constantly fiddle with knobs trying to outsmart the automatic system and maintain a comfortable inside temperature.
I suspect that my problem is Honda's implementation of measuring the current temperature. By all my tests, I'd swear on a bible that my car always determines the temperature of air to pump out based on the reading from outside the car - even when Auto is not engaged.
Here's my scenario and I don't think it's too much to ask: I basically would like my car to feel like 70 degrees all the time That's it. Nothing crazy. However, here's what happens when I press Auto and dial in 70.
If it's 85 degrees outside and you're set to 70 on the panel, the system will blast cold air forever, until you're a popsicle. You have to dial the number progressively higher to get the system to back off the freeze ray. On the flip side, if it's 35 degrees outside, the system will blast heat forever, until you're BBQ.
Leaving the system dialed at 70 and Auto is completely uncomfortable and the car quickly becomes uninhabitable unless the temperature outside is right around 75. If you live in California and conditions are pretty much always like this, then I guess this works, but for me, where it was 80 on Saturday and 35 on Monday, leaving my car at any automatic setting will yield either a neverending furnace or icebox.
Here's the really bad part. After realizing the system was ignoring the extreme temperatures it was creating inside the cabin, I decided to give up on Auto and just dial in a temperature manually. Guess what? That doesn't work either. Today, it was 35 outside. I had the fan set to just one notch and the manual temperature set to around 68.* After the car got nice and warm inside, the hot air just kept on coming. If this was truly a manual setting, 68 degree air shouldn't be hot, but that's what the system kept pumping out. As beads of sweat started to form on my forehead, I began to move the manual temperature down. Even getting to manual temperature of 60, the system was still pumping out heat. With a truly manual system, I would have been fully into the "blue," but the Honda system didn't care.
I can only guess this was because it was set to 60 and was still measuring the difference between that and the outside temperature, which was still 35. I suspect this delta is what the system uses to determine whether to pump out cold or hot air. The problem is, no matter how much it heats the cabin, the outside temperature isn't going to change, so it just keeps on heating. At that point, I'm in a situation where Auto 60 is too hot and Manual 60 is too hot. If you crank the temperature even further down, it will revert to "Lo," but even that is no good because that just engages full on blizzard mode again. There's no way I can figure out to get the system to blow moderate temperature air, if the outside temperature is extreme.
As far as I can tell, there's no middle ground way to set this system and forget it if it's either very hot or cold outside the car. If you don't want either a furnace or an icebox, it requires constant attention throughout a car ride as the internal cabin temperature and outside conditions vary. At the extremes, you're forced to turn the system completely off and open a window to reverse the overcompensating automatic temperature brain. In short, the system seems over-engineered or at least poorly engineered. It thinks it's smarter than the driver. Problem is, it often completely fails at its primary job, which is to maintain a comfortable cabin temperature with minimal user interaction.
It's one of numerous grating issues with this car. There are a lot of positives, but there are a lot of nagging issues that grate on you if you drive the car every day. I don't think Honda did proper QC on this car before sending it to dealers.