Success: AUTO mode heater only AND A/C disabled.

I have read all the threads (whew!) but cannot find anyone with quite the thing I was looking for.
I wanted to use the AUTO mode to control the heater, flow modes, and fan, but I did not want the A/C to be on.
We all know that when you are in AUTO and push the AC off, the AUTO turns off. BUT here is the key combination that worked around that problem.

1. Push AUTO on
2. Push Defroster on (AUTO stays lit)
3. Push AC Off (AUTO turns off)
4. Push Defroster off (AUTO turns on, But AC does NOT turn on)

This leaves the AUTO button turned on with heater, flow, and fan functions only.
(illogical, but true. Some might call it a bug, but I think of it as an Easter Egg).

Now the Heater turns on and off automatically (confirmed using Energy status screen) and
. . . the fan speed turns up and down automatically and
. . . . . . the dash versus floor flow mode works automatically.

When the interior is cold, the heater turns on and fan goes up. When the interior gets too hot, the heater turns off and fan goes to lowest setting. Since the outside is cold and the fresh air button is lit, the interior slowly cools down. Then the heater kicks back on. (still seems weird I cannot use recirculate in auto mode.)

Put the thermostat to 90 and the heater cranks up with fan setting ramping up from 1 to 4 very quickly and switches to floor flow.
Crank the thermostat to 60 and the heater turns off and the fan ramps back down to 1 very quickly and it switches to dash flow.

So, now I have the thermostat set at 72 and just use the climate control on/off button to turn the AUTO heater-only mode on/off.
(yes, it remembers the AUTO heater without AC mode when I turn the climate control on and off and then on again).

If someone forgets and touches the AUTO button and turns the AC mode on again, no problem. Hit Defrost/AC/Defrost sequence again and we are back in AUTO Heater-only mode once more.

Jerry

Just curious, but why would you want to disable the A/C? It's very little power draw compared to the heater and helps keep the windows from fogging up...

GeekEV said:

Just curious, but why would you want to disable the A/C? It's very little power draw compared to the heater and helps keep the windows from fogging up...

Click to expand...

True it is very little power draw, but it was my subjective sensation that the AUTO function was switching from heating my feet to cooling my face and back to heating my feet, rapidly as it bounced a degree or two on either side of the thermostat setting. My windows don't fog up (SoCal Inland Empire is kind of dry place, but can be quite cool in the winter mornings.) I use the pre-heat function, but my commute is long enough that there were times that I wanted to turn the heater on but not the A/C on too.

p.s. You guys who live in truly cold places stop laughing at my "quite cool" remark now.

I am totally not convinced that "A/C = cool" in this car. I believe A/C means condition the air: heat it, cool it, dry it, whatever it needs. I think what you have found is a bug in the software, where they really have the A/C on but failed to turn the light on. If it subjectively makes you feel warmer not to be able to see that little light, I don't want to take that imaginary pleasure from you, so go ahead and use your "fix" until Nissan gets around to shipping their fix to the software.

Ray

Ray, you could be right when you say the AC is still turning on in this variant of AUTO. If that is the case then another part of the bug I stumbled across is they failed to allow the Energy usage screen to show the AC is turning on while still allowing the Heater to show on the energy usage screen. I bet someone here has the equipment to figure out if this variant on AUTO turned off two functions, the AC light and the AC energy usage screen OR if this variant only turned off the AC for real.

planet4ever said:

I am totally not convinced that "A/C = cool" in this car. I believe A/C means condition the air: heat it, cool it, dry it, whatever it needs. I think what you have found is a bug in the software, where they really have the A/C on but failed to turn the light on. If it subjectively makes you feel warmer not to be able to see that little light, I don't want to take that imaginary pleasure from you, so go ahead and use your "fix" until Nissan gets around to shipping their fix to the software.

Ray

Click to expand...

I'm not a Nissan engineer, so I'm not saying this authoritatively, but I think A/C means the same as it does on any other car, and that means that it is running the A/C compressor unit and thus uses more power than is necessary. Yes, we are used to thinking of A/C as making things cold, but while the compressor unit DOES have that ability, it doesn't necessarily mean it has to actually be cooling. When the temp is set high, it is not cooling the air, but rather just dehumidifying it.

This is basically what you are saying, with the exception of the statement that heating implies conditioning. I don't believe it does.

This is the way it works on practically all other cars with an A/C button. You CAN turn it on in the winter while the temp is up to hot and yes it does prevent fogging of the windows. In fact, most cars will automatically turn the A/C on when you put the vent in defog mode, whether it lights up the A/C light or not. So this is not a new concept that Nissan invented for the LEAF. What IS new is the fact that you can't turn off the compressor unit while in AUTO mode when heating. My theory is due to the fact that from the car's point of view there is no "heating" or "cooling" mode, there is just a continuum of temperatures you can set, so the system complies by turning on the A/C compressor and adding or removing heat as necessary to achieve the set temperature. If it was a summer day, you would expect the A/C to come on when you hit AUTO, but the car doesn't really know whether it's winter or summer and whether you want the car warmer or colder, it just knows you want it at 72F.

Sure, the power draw is small compared to the heater running at full blast, but if it's not necessary for your own condition (i.e. your windows are not fogging up), what point is there to running it? It's just wasted power.

Here is how I've gotten my brain around this whole issue, and this is just my preference--yours will certainly be different. I also haven't done a lot of experimentation because (a) I haven't had the LEAF that long; (b) it's been warmer here and (c) my wife gets to drive it most of the time! However, when I do get to drive, I use the heated seats and steering wheel quite effectively. That pretty much keeps my upper body comfortable, but my legs do get pretty cold. So I'm in a situation where I only want the heat to be directed at my feet anyway (or foot/defog if the windows are fogging up). So I don't really want AUTO messing with the vent positions anyway. Additionally, because you MUST set a temperature rather than a simple slider that goes from blue to red like on a traditional car, I believe (but have not positively confirmed) that even when not in AUTO, the system does automatically modulate the heater unit to maintain the set temperature. Based on a limited number of checks of the Energy Usage screen and the fact that the heater does tend to draw vastly different amounts of power even when I haven't touched a button, I do believe this is the case. So from my perspective, I AM getting all the benefits of an "AUTOmatic" mode that I want. I am only missing out on the ability for the system to automatically redirect the air to the face vents (which frankly I don't really want anyway).

lpickup said:

planet4ever said:

I am totally not convinced that "A/C = cool" in this car. I believe A/C means condition the air: heat it, cool it, dry it, whatever it needs.

Click to expand...

I'm not a Nissan engineer, so I'm not saying this authoritatively, but I think A/C means the same as it does on any other car, and that means that it is running the A/C compressor unit and thus uses more power than is necessary. Yes, we are used to thinking of A/C as making things cold, but while the compressor unit DOES have that ability, it doesn't necessarily mean it has to actually be cooling. When the temp is set high, it is not cooling the air, but rather just dehumidifying it.

This is basically what you are saying, with the exception of the statement that heating implies conditioning. I don't believe it does.

This is the way it works on practically all other cars with an A/C button. You CAN turn it on in the winter while the temp is up to hot and yes it does prevent fogging of the windows. In fact, most cars will automatically turn the A/C on when you put the vent in defog mode, whether it lights up the A/C light or not. So this is not a new concept that Nissan invented for the LEAF. What IS new is the fact that you can't turn off the compressor unit while in AUTO mode when heating. My theory is due to the fact that from the car's point of view there is no "heating" or "cooling" mode, there is just a continuum of temperatures you can set, so the system complies by turning on the A/C compressor and adding or removing heat as necessary to achieve the set temperature. If it was a summer day, you would expect the A/C to come on when you hit AUTO, but the car doesn't really know whether it's winter or summer and whether you want the car warmer or colder, it just knows you want it at 72F.

Click to expand...

I don't know the definitive answer, but I wanted to insert that one of the Nissan people at the December 2011 BayLEAFs meetup explained that, unlike in the U.S., in Japan, AC does not imply "cooling" but has a more literal "air conditioning" meaning of "heating or cooling". (I don't know what the actual labels say on the Japanese version of the car.) Anyway, he went on to say that they were embarrassed to not have caught that misuse of the term AC in the design of the climate control for the LEAF in North America. It's not clear to me whether he means that that it would be labelled differently (that doesn't seem right since all cars have an A/C button) or if the light just shouldn't come on when heating or what. And I had the impression that it was something minor that they still intended to fix. Can anyone else who was there describe what they heard?

And just a comment... the car * can * essentially "know" whether it's winter/summer and you want warmer/cooler since it knows the outside temperature and your requested temperature.

JK,
in ur post, defrost means what?
front or rear?

While unplugged and in "green car" (ready) mode, I have verified for certain that the heat does come
on without the A/C being lit and that the compressor does not. (Using the CC energy meter
and listening - the compressor sounds different than the water pump.) So, whatever the language
variables, the A/C button does, in fact, control the A/C compressor in that mode.

That said, the A/C button must be lit to get heat while plugged in, IF you turn on the heat from the
car. Of course CW turns on the A/C light if you do it remotely.

So, there seems to me to be no sense that the A/C button even has a consistent meaning. Several different
bits of firmware seem to react differently. :?

lpickup said:

<snip>
I'm not a Nissan engineer, so I'm not saying this authoritatively, but I think A/C means the same as it does on any other car, and that means that it is running the A/C compressor unit and thus uses more power than is necessary. Yes, we are used to thinking of A/C as making things cold, but while the compressor unit DOES have that ability, it doesn't necessarily mean it has to actually be cooling. When the temp is set high, it is not cooling the air, but rather just dehumidifying it.

This is basically what you are saying, with the exception of the statement that heating implies conditioning. I don't believe it does.<snip>

Click to expand...

EDIT: Typo

Christopher said:

And just a comment... the car * can * essentially "know" whether it's winter/summer and you want warmer/cooler since it knows the outside temperature and your requested temperature.

Click to expand...

"Can" and "does" are very different things though! I think there are 3 clocks on the car and none of them actually talk to each other! Anyway, I should have said "as currently implemented, I doubt" that the car can tell whether it's winter or summer.

As for the terminology thing, I've heard that argument, but as an American that's owned many cars, I've come to understand that the AC button and/or light in my car, whether it's a Dodge, Chrysler, Volkswagen, Jeep or Nissan means simply that the compressor is on, so I don't think it's a misunderstanding at all, or inconsistent with what other vehicles are doing. The difference here is simply that when you hit AUTO it automatically forces AC on, and when you hit AC, it turns AUTO off (although more specifically if you hit almost ANY other button it turns AUTO off, so the two are not inherently linked). As for the fact that they meant for the AC button/light to indicate that the climate control system (i.e. heating OR cooling) was active, I don't buy that at all. There is already a Climite On/Off button, and a display that indicates whether the Climate System is on or off (not a light, but rather a touch screen display).

I have an "excedrin headache" from reading all the posts regarding heating/cooling/defrosting for the Leaf. Whatever happened to:

Push the climate control button; set the temperature to (whatever) degrees, and fuggetaboudit. :? :?

I guess I'm lucky I live in San Diego, so I really don't need heat or air conditioning most of the time.

Christopher said:

the car * can * essentially "know" whether it's winter/summer and you want warmer/cooler since it knows the outside temperature and your requested temperature.

Click to expand...

It also knows if the sun is shining, or not.

thankyouOB said:

JK,
in ur post, defrost means what?
front or rear?

Click to expand...

front

jkyu99 said:

I have read all the threads (whew!) but cannot find anyone with quite the thing I was looking for.
I wanted to use the AUTO mode to control the heater, flow modes, and fan, but I did not want the A/C to be on.
We all know that when you are in AUTO and push the AC off, the AUTO turns off. BUT here is the key combination that worked around that problem.

1. Push AUTO on
2. Push Defroster on (AUTO stays lit)
3. Push AC Off (AUTO turns off)
4. Push Defroster off (AUTO turns on, But AC does NOT turn on)

This leaves the AUTO button turned on with heater, flow, and fan functions only.
(illogical, but true. Some might call it a bug, but I think of it as an Easter Egg).

Now the Heater turns on and off automatically (confirmed using Energy status screen) and
. . . the fan speed turns up and down automatically and
. . . . . . the dash versus floor flow mode works automatically.

When the interior is cold, the heater turns on and fan goes up. When the interior gets too hot, the heater turns off and fan goes to lowest setting. Since the outside is cold and the fresh air button is lit, the interior slowly cools down. Then the heater kicks back on. (still seems weird I cannot use recirculate in auto mode.)

Put the thermostat to 90 and the heater cranks up with fan setting ramping up from 1 to 4 very quickly and switches to floor flow.
Crank the thermostat to 60 and the heater turns off and the fan ramps back down to 1 very quickly and it switches to dash flow.

So, now I have the thermostat set at 72 and just use the climate control on/off button to turn the AUTO heater-only mode on/off.
(yes, it remembers the AUTO heater without AC mode when I turn the climate control on and off and then on again).

If someone forgets and touches the AUTO button and turns the AC mode on again, no problem. Hit Defrost/AC/Defrost sequence again and we are back in AUTO Heater-only mode once more.

Jerry

Click to expand...

Thanks for the tip Jerry. Will try it out tomorrow.

For the cold days, the main kicker is the need to enable Recirc. This prevents the warm generated inside the cabin from getting cold again.

Some day when it's warm enough I'll test this but I don't thing the A/C light mean the compressor is runnning.

Every car I've had until now that had an A/C light simply meant that the A/C system was enabled. The real control of the
compressor was the temperature. You could stand in front of an ICE car with the engine running and watch the compressor
start and stop and hear the clutch snap in when the interior got warm and needed cooling. Also when the front window defrost
was selected, the compressor started and the air coming out was colder than what previously came out at your feet. To keep the
defrost temp warm, I had do crank up the temp setting. If and when spring comes up here, we'll have a little fun trying figure out the Leaf system. For now, push a few buttons and I get what I want. No big deal.

Brent is correct; the A/C button being lit DOES NOT mean the A/C system is running; simply that it is possible for it to run if the HVAC ECU deems it necessary. It generally only runs when the defrost is enabled either by the button or the mode selector, and conditions are such that running it will help dehumidify the glass. It drains very little power and doesn't "freeze" you, all it does is create a slightly colder surface in the evaporator coil such that the humid air will condense there and thus the moisture is removed from the air stream.

The big problem is the heater; it cannot be disabled without shutting the climate control entirely off, at which point the car seems to retain excessive moisture.

-Phil

derkraut said:

Whatever happened to: Push the climate control button; set the temperature to (whatever) degrees, and fuggetaboudit. :? :?

Click to expand...

What happened is that the whole vehicle got more efficient. With an ICE vehicle routinely throwing away 75% of the energy you give it, it's hard to even notice the effects of a climate control system. The LEAF needs so much less energy to move on down the road that formerly negligible uses like CC now are a significant factor.

I have to admit that I started out with the set-and-forget mindset, and only after reading some of this stuff did I experiment with settings. Well, that, and I discovered to my surprise that it actually had an affect on the range. But like you, I'm in S.D., and I don't have to care if I don't want to

I just went for a joy ride and tried the method suggested and this does seem to lock out the A/C.

I sure wish Nissan made the temp control go down to say 40 so we could run the fan with the heat set very low
so it would not come on, or come on very little.

brent said:

Some day when it's warm enough I'll test this but I don't thing the A/C light mean the compressor is runnning.
<snip>

Click to expand...

*nods* True.