Now that the weather is starting to warm up a bit, I've discovered that the "A/C Auto" mode on my Bolt's HVAC system has some pretty radical ideas about what the temperature control should do. In fact, I suspect that ALL of our Bolt EVs may be afflicted.
I borrowed a temperature logger from work to try and figure out what was going on and captured cabin temperatures up into the high 90ºs after letting the car run at 74º in "auto" for an hour.
It's important to note: The air conditioning unit itself works fine mechanically. How do I know? Because by setting the controls to 70º, the cabin temperature confidently dropped until settling into the low 60s. Wait, what? I think my Bolt's thermostat is drunk.
As far as my dealer is concerned, the heater is heating just fine and the A/C is cooling just dandy, so it is the assessment of their "factory-trained technician" that everything is working as designed. They kept my car for three days before arriving at this conclusion, so at least they were good and thorough about putting the system through their prescribed tests. (As an aside: If I hadn't already come to appreciate the brilliant engineering of the Bolt's electric drive, those three days I spent in the combustion-engine loaner they set me up with certainly convinced me!)
This might be a bigger deal than my Bolt alone merely experiencing a chance defect in a piece of 1880s tech. I tried the same experiment with my coworker's vehicle (in exchange for topping off his battery) and observed the same result! Uh-oh.
Chevrolet Customer Assistance, who had graciously set up my dealer appointment, doesn't appear to have any interest in following through on the possibility that our entire model of car may have shipped with a malfunctioning thermostat. They claim that nobody else has had this problem, so based on the report from my dealer's "factory trained technician" that my car is working as designed, there's no need for them to investigate any further. Even after escalating to a manager level, their position is that there's nothing wrong with my Bolt's HVAC, or anyone else's.
So, forum members: Set your thermostats to 74º (or 75º) and turn Auto mode on, and see what happens!
Last edited by rybolt
on Mon Apr 24, 2017 3:36 am, edited 10 times in total.