[MikeyBolt]

After driving my 2019 for a while with the climate controls set to auto and 72F, I decided that was a hint too cool so I changed the temperature to 74. After setting it to 74, I noticed that when I get in the car and it's under 90F outside and the car isn't parked in the sun, the AC won't come on. It happened once at 88F outside temperature and once (today) at 82F. Today I even drove it for about 5 minutes to see if it would eventually come on but it didn't. The cabin started warming up more until it was uncomfortable and then I turned it down 1 degree to 73F at which point the AC came on and it cooled normally. It does come on if I have it set to 74 and the car is in the sun where the inside is blazing hot, but if I start out from the garage in say mid 80's outside temp, it doesn't seem to want to kick in until, maybe, it gets really hot in the cabin.

Has anyone else noticed anything similar? It's almost like, if I set it to 74, it has a mentality of "Meh, he'll be fine... it's not that far off" and when I switch it to 73F it's like "Oh... he's serious now."

Mike

 

[XJ12]

I only use three degrees in the summer. 70, 71, & 72. Anything else is either too cold or too hot. Well maybe I'll set it on 68 or COLD if I've just played a tennis match or finished a round of golf before getting in the car. Once I cool off, it's back to the three degrees, 70, 71 & 72.

 

[psyflyjohn]

Seems to me, the "Auto" Temp control is simply imperfect. Same with my thermostat in the house for heating/A/C. It's difficult to anticipate all environmental conditions and correct for them. I just tweak the thermostat (or Auto setting) as needed. One could go crazy trying to get these systems to work perfectly. That said, usually leaving the setting on Auto in the Bolt usually takes care of things 90% of the time...

 

[Terry Hancock]

I have a mid 2018, and have never changed it from 76. It comes on in any condition where the outside air is above that. I have never had that auto setting fail. *I live in NM.

 

[Sibilance]

78 degrees is my family's preferred temperature for our house and car during the Relentless 3 Seasons of Summer we have in Central Texas.

If I set my Auto to 78 in 80 degree weather IT TURNS ON THE HEAT.

NOT the auto defrost. It turns on the heat, until the car is above outside ambient temperature at 85 to 86 degrees.

In 96 degree weather, which is common in May and June, setting to 78 degrees gets me an interior temperature of 85 degrees. Measured by a thermometer.
To get 78 degrees in my car during hot weather I have to set the auto setting to 72. I keep a usb powered thermometer in the car to keep track, because I have a 5 year old and children die every year in Texas from heat exposure.

I suspect that the interior thermometer in my car is flaky and reading 6 degrees too low or so. The sensor is located in the Black Box up on the windshield according to the parts diagrams I have looked at.

Decades of interactions with American Car Dealerships have trained me NOT to take my car in for something 'minor' like this unless I absolutely have to. I'll get the car back with something more expensive and sensitive broken.

My GEN 1 Volt, however, was rock solid and accurate. 78 degrees on Comfort got you 78 degrees. 78 on Eco would let the temperature drift upwards four degrees, but never actively heated the interior on a hot day.

 

[surgeonFWW]

If I am correct, there is no digital indication of what the temperature is inside the EV, OR what the thermostat thinks it is. The outside temperature IS displayed. Occasionally, e.g. when the outside temp is say 80, I'll set the inside temp to 74 (to save power over a setting of 72) and the heat comes on because the EV thinks it is 73 inside. Yes, the temp inside the garage is probably around that, but it may be a capricious thermostat. I like to use "Auto" also, but the fan goes overboard in cooling. I then ratchet the fan speed down, but, of course, that throws me off "Auto". I still have no idea of what the inside temperature is, or, more importantly, what my Bolt considers it to be.

 

[Sibilance]

Yes, there's no interior temp display. I use a little USB thermometer, and have since my baby was born. Every so often I check them against known good Thermometers in my house, toss them when they get really inaccurate. Currently one of these:

Keynice Digital Thermometer, Temperature Sensor USB

In the attached pictures, I have auto defrost on, so where it shows 'heat' the heat is actually not blasting.

Still getting 85 degrees when I set to 78. While in my insulated garage, which is at 85 degrees.

The last photo shows where the temperature sensing lead is. This is approximately the same level as my child's torso in the rear of the car.

 

[Sean Nelson]

Seems to me, the "Auto" Temp control is simply imperfect. Same with my thermostat in the house for heating/A/C. It's difficult to anticipate all environmental conditions and correct for them.

My Prius C had an automatic climate control system that worked pretty well. It's main distinguishing feature from the Bolt was that I could set it in 1/2°C increments instead of the whole °C increments that the Bolt uses. I generally find 22°C to be a little too cold and 23°C to turn off the A/C altogether - I've always suspected that it would be perfect if only I could select 22.5°C.

The thought has recently occurred to me to just set it to 22°C on Auto and then to manually adjust the fan speed down a notch or to. I'll have to give that a try to see how it works...

 

[MikeyBolt]

My Prius C had an automatic climate control system that worked pretty well. It's main distinguishing feature from the Bolt was that I could set it in 1/2°C increments instead of the whole °C increments that the Bolt uses. I generally find 22°C to be a little too cold and 23°C to turn off the A/C altogether - I've always suspected that it would be perfect if only I could select 22.5°C.

The thought has recently occurred to me to just set it to 22°C on Auto and then to manually adjust the fan speed down a notch or to. I'll have to give that a try to see how it works...

That's what you get when you only have 100 steps between freezing and boiling.

Mike

 

[Sean Nelson]

That's what you get when you only have 100 steps between freezing and boiling.

I know the US is behind on the metric system, but haven't you guys learned to use decimals yet?

 

[Dimitrij]

I don't know how to explain it (the Bolt is too complicated for me), but it is so indeed: 73F is somehow too cold and 74F - too hot (in the front seats). For comfort in the back seat, I am told, the AC needs to be set at 72F, which corresponds to "very cold" in the front seat and 7% to 11% energy penalty in normal driving conditions outside.

This car is a 3,600 lbs of mysteries

 

[NJ Bolter]

Like many of you, I've been frustrated by an inability to figure out why 73° sometimes provides air conditioning and sometimes provides heat. It does not seem to follow any rhyme or reason.

I thought that it was a quirk in the 2017, and that the software upgrade in the 2019 that separated the heat and air-conditioning functions would solve the problem. Apparently I was wrong.

I discussed it with the local dealer who advised me to bring it in. After spending a week at the service department, the advisor assured me that the HVAC system is operating to "spec".

As an aside, when shopping for the car I asked the sales rep what number is displayed on the HVAC. He said it was the interior cabin temperature.

Still, above all else, the Bolt is a wonderfully reliable and fun car to own and operate.

Bernie

 

[XJ12]

I know the US is behind on the metric system, but haven't you guys learned to use decimals yet?

two-thirds of us still use fractions.

 

[MikeyBolt]

two-thirds of us still use fractions.

You would have to pick a fraction that I can never put into my calculator exactly.

I actually wish I was brought up metric since I've switched to metric for most things (things I have to measure for example). I just never switched to C because F brings about a "feeling" for me and it's hard to switch. Plus I never have to convert to different scales like millidegrees or kilodegrees so I never bothered.

Mike

 

[121 Kw]

Funny, I set mine to 74ºF the majority of the time because I feel like the A/C is a little over active below that. If it's too hot in the car I dial it down to 72ºF to get the A/C to come on. However, set at 74ºF it does precondition the car to my liking for both heat and cooling.

 

[Bolted On]

I like to use "Auto" also, but the fan goes overboard in cooling. I then ratchet the fan speed down, but, of course, that throws me off "Auto". I still have no idea of what the inside temperature is, or, more importantly, what my Bolt considers it to be.

I also adjust my fan to lower than the "Auto" setting seems to choose. However, the manual mentions that the other Auto functions continue to function on automatic even if one setting is manually adjusted.

Concerning my preferred temperature settings, it is 74º. Occasionally I'll have to drop it one degree to augment the cooling. As others have mentioned, in cooler weather, the Auto setting will activate the heater even though A/C is manually set. Definitely the algorithm is not getting it right in all conditions.

 

[MikeyBolt]

We had our first cool morning today since I got my 2019 in June. I've been keeping my HVAC set to 73 as that temperature seems to give the proper amount of cooling here in FL. It was 56F outside when I set out this morning and with the HVAC set to 73, it was in AC mode blowing cold air at a pretty moderate fan speed. I left it on 73 for about 5 minutes to see what it would do but it kept cooling even though it was 56F outside and maybe 60 in the cabin. Turned the HVAC up one click from 73 to 74 and it switched from AC to heating immediately.

Sorry, but this HVAC system is simply garbage!

Mike

 

[GJETSON]

I find it very frustrating that our 2017 doesn't have separate Heat and AC controls. But my head would explode of I had separate buttons, and still couldn't get it to only do one or the other.

What about this concept is so hard for GM to understand? It is not that the Heat and AC are either on or off. On Torque Pro, you can see the heater wattage going up and down, and AC compressor spooling up and down...often with both fighting each other.

 

[psyflyjohn]

Hey folks - It's basically a Chevy. Do I need to say more?

 

[Eriamjh1138]

The HVAC attempts to reach the set temperature inside the cabin. It does not care what the outside temp is. It’s irrelevant.

You thought the interior temp was 60F. It probably wasn’t. Not at the sensor.

The cabin interior sensor is somewhere in the interior. When the cabin temp is below the HVAC temp, it heats. When above, it cools.

I dont think there’s anything magical about 74F. The actual interior temp is basically at 73.5F when you get heat at 73 and cooling at 74 HVAC Settings. Turn the airflow to be at your feet and you won’t notice it trying to regulate on the edge.

Having heat only would prevent this. Not an option in 2017 models.