Is HVAC burning you up too? Chevy says "nothing wrong"

[michael]

OK....

I have a new Volt. The first two days I had it, the climate worked fine. This morning I noticed:

1. The car was fully charged, but the EVSE "trouble" light was blinking
2. With the fan on manual, I could control the heating/cooling, but when I put it on Auto, the fan slowed down (maybe stopped) and the car started slowly heating up
3. I pulled to the side of the road, turned the car off-and-on and the situation persisted.
4. At work, I plugged into the EVSE, and all is OK with the climate (at least for now)

I wonder if there is some mode the climate can get into if charging stops unexpectedly. I'll let you know if I see this again. And it's on a Volt, not Bolt.

 

[rybolt]

I wonder if there is some mode the climate can get into if charging stops unexpectedly. I'll let you know if I see this again. And it's on a Volt, not Bolt.

With regard to setting the "auto" climate control to 74º and eventually having the cabin climb past 86º, I've noticed no difference whether the Bolt is: Driving in hot weather, driving in cold weather, parked and charging, parked and not charging, daytime, nighttime, rain, shine, or whether it's Thursday.

MEANWHILE, here's a wee update: Of course my car passed the "Air Conditioning System Performance Test" at my dealer a few weeks back. The test consisted of running the system at "the coldest temperature setting" while measuring the temperature of the air produced at the vents, so there was very little surprise (at least in my mind) when my Bolt happily produced cold air in that scenario.

But...my dealer reps (bless their hearts) have continued to follow up with GM and my car is back in the service bay today for a "Vent Temperature Sensor Diagnostic"

...I'll let you all know what happens!

EDIT: I'm in a loaner Malibu. How much does gas cost these days?

 

[bbock]

What was the follow up to this?

 

[rybolt]

I apologize for not posting an update for quite some time. However, I don't have anything new to add, yet.

My dealer DID convince GM to send a field tech to look at my car, and this behavior did manage to raise both his eyebrows. Still waiting for the next steps, though...

 

[wubaoguo]

Obviously this is defect from manufacturing. I have exactly same issue. Occasionally it blows hot air when it is supposed to cool down or simply there is no cooling at all. And this usually happens after cooling was working for first few minutes then it is off by itself. If I feel the air with my hand I no longer feel the cool air.

I'd say this is the only beef I have with Bolt.

 

[OlyCamasu]

My 2018 doesn't have an Auto button, so my car's issue isn't quite the same. What I can do is set a desired temperature, then choose to have the AC/heat on (a "guarantee" of that temp that uses more battery) or off (the vents blow whatever air temp is ambient and use less battery). I find that if I am driving more than half an hour at a time, the car will flip back and forth between having the AC/heat on and not, regardless of what I have chosen. Quite frustrating, that I can't either 1) keep the temp that I want (if I chose climate control), or 2) avoid using battery unnecessarily (if I chose not to turn on climate control).

Is anyone else having this issue?

 

[dborn]

I'm so glad I found this thread!
My 2019 Bolt is displaying similar behaviour, where clearly A/C should be outputting cool air but instead, it's giving out intense heat.

I've only had this happen a few times, once in "precondition" mode. It must have been 34C+ weather out and car was sitting in the blazing sun for a few hours. I remotely started a precondition only to return within 20 minutes to find the car's interior extremely hot and hot air coming out the vents. I probably had the thermostat set to 23C (73.4F, sounds familiar?)

Another time, I was in the car and started the climate control myself in similar conditions and the system also went straight into Heat mode. I had to turn down the thermostat to 20C before getting any kind of mild cool (and slow fan) happening in Auto mode. As the car's interior started to cool down, the fan speed picked up and the air got cooler. I then gradually brought the thermostat back up to 23C so it wouldn't be too cold inside the car, all the while keeping the system on Auto A/C mode even if the car's interior got progressively cooler.

I went to my dealer today and got the "working normally" line. They say they checked for TSBs and found none but that doesn't mean anything. My car was manufactured in June 2019 for the Canadian market. (LT model).

I'm glad to know I'm not alone with this issue...

 

[theothertom]

I didn't real through all 5 pages of comments, so I don't know if this has been mentioned, but the Bolt has an automatic defrost setting that makes the heat (or A/C) come on when you least expect it. I believe the function is set to "on" by default. You can change it by going into the settings and changing it to "off". I didn't have any more problems with phantom heat or A/C when I changed mine to "off".

 

[dborn]

Thanks but it's definitely not my issue. The Auto Defog has been turned off on day 1 and I also confirmed it is still off now. I read the entire thread and it contains alot of good information explaining the issue.

**Edit: I did the 15 minute check identified in TSB 17-NA-049 and my car doesn't have the pinched wire.

 

[Kevhearn]

Yes I have the same issue with my ac. If I try to set thermostat above 70 d.f. The car will get very warm , so I leave it at 70 at all times and ac works fine, if I get to cold I turn down the fan. Never was a big fan of thermostat settings in cars