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Discussion Starter #1
Hi All,
In Australia where winters are fairly dry and most areas we DO NOT suffer from the the need to remove cabin condensation / fog, is there any way to override electronically, electrically or mechanically to stop A/C operation while heating.

It is absolutely crazy that in Eco / Max climate controls it decides to run the A/C while heating to dehumidify.
1) Wastes heating energy (reducing range)
2) Runs the A/C reducing the cabin heat output and after the dehumidify cycle noticed it actually creates a humidity problem and has to run the A/C to remove it..... in other cars where you can override this a humid issue would never occur in most of the climate conditions encountered.

Yes in Wet / high humidity conditions I understand the use of running the A/C, so why hasn't GM given us the ability to override the climate control system? Do they not trust us as drivers?

Has anyone any solutions in regarding to override the A/C operation? as I'm very tired of setting the heater to min for very little heat - just to avoid the A/C running in our dry mild winters. Found an Australian article where a journalists drove from Sydney to Melbourne and had this exact complaint.

Can we expect GM to do the right thing and offer a software update in future?
Otherwise no more GM climate controlled cars in the future for those that have to live with this during our winter months. (Thank goodness it is summer here currently in the land down under). But next winter grrrrr.
 

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I don't think so, the best 'solution' I've come up with is to set them temp to 'max', and switch between comfort/eco heat and fan only. When the air blowing drops in temp, I put the heat back on. The ac seems to come on less this way and I use less overall energy vs setting the temp to 23C...but you really have to baby the system.

Also make sure auto defog is set to off in your settings. Otherwise the ac will run even in fan only mode I think.
 

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Why hack this car? The amount of power that little freon compressor uses is minimal anyway.
Norton is correct, the AC is surprisingly efficient. Just relax and turn off that climate display.

Even though your climate is very dry, you have a source of moisture inside the car; breathing people!
 

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Do you know about the 'Auto-Defog' config setting?
Yeah. I think simply turning off Auto Defog would solve this problem.

And then if you did develop moisture problems but still wanted to avoid using AC, turning off recirculate would also help.


Lastly... there's probably some way to manually modify the electrical signal coming from the humidity sensor to fool the car into thinking that cabin humidity levels are lower than they actually are, similar to how people add resistors in parallel with the outdoor temperature sensor to fool the car into thinking that it's warmer outside than it actual is.
But how to actually do this (or even where to locate the humidity sensor), I have no idea.
 

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Have to agree with posts. I have studied it and it uses an incredibly small amount of electrical energy.

What I want is the opposite - AC without heat!! I can deal with a bit of cold in single digit C, but can't deal with a fogged window!
 

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Discussion Starter #7
I don't think so, the best 'solution' I've come up with is to set them temp to 'max', and switch between comfort/eco heat and fan only. When the air blowing drops in temp, I put the heat back on. The ac seems to come on less this way and I use less overall energy vs setting the temp to 23C...but you really have to baby the system.

Also make sure auto defog is set to off in your settings. Otherwise the ac will run even in fan only mode I think.
Cheers pcons I'll give this a try and yes auto defog is off but will double check. I understand from the other posts the A/C does not use much engery. This issue is cuts the efficiency of the HEATER which does use ALOT of energy - So you can see the crazy situations here using A/C tol counter act the heat. MY other GM ICE car has Manual HVAC controls and I just love it as you can set it exactly to what use need efficiently. Only in extreme days do I use the A/C demist function where as the Volt is just over dam sensitive.
The next car I buy will be manual HVAC or a dam good climate control that I can actually override to my local climatic conditions.

I'll work on the humidity sensor and see If I can trick it, but some of the new system are very clever at monitoring their sensors signals
But this may be just the ticket to fixing this issue down under as I have some time being summer time here in OZ and the climate control works ok for Summer with A/C spot on. But In Winter if I can't fix it I'll be driving the old ICE car more which not what I want to do again.

Cheers,
Martin
 

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.....I'll work on the humidity sensor and see If I can trick it, ....
Cheers,
Martin
Yes, do this Martin.
Then you can proudly claim, "I saved a Buck and a Half in electrical costs last winter by not having the AC compressor cycle on and off when it was supposed to".
 

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Discussion Starter #9
Yes, do this Martin.
Then you can proudly claim, "I saved a Buck and a Half in electrical costs last winter by not having the AC compressor cycle on and off when it was supposed to".
What?? you on about - I'm not doing this to save a buck and half - I'm doing it to have decent constant heating not interrupted by cooler waves of having the stupid A/C cycle on.

Maybe you are lucky Norton and your Volt heating works way better than the versions we ended up in Australia. I'm sure if you tried our Volts out here you would understand and agree that they completely SUCK in the heating department & local motoring journalists agree.

Mine improved dramatically with a software upgrade (Built 2012 for 2013 model year) the one with all the problems in this HVAC department, originally I was getting really cold gusts - crazy for a Car we pay $65K AUD for and they only sold 243 of them for this reason. (You can buy 2 to 3 cars at this size for the price of the Volt in Australia - so please don't lecture me about trying to save a buck - I feel insulted! )
 

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.....I'm doing it to have decent constant heating not interrupted by cooler waves of having the stupid A/C cycle on.
....- I feel insulted! )
Sorry, I didn't understand the climate control was giving you 'cooler waves'.
I thought you were just going on about the 'Snow Flake' icon cycling on and off on the center display.
You Aussie Volt owners need to demand a decent climate control system.
The NA Volts seem to work without 'cooler waves'.

What happens if you tape a tissue over the display so you can't see the 'snow flake'?
 

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Discussion Starter #11
Sorry, I didn't understand the climate control was giving you 'cooler waves'.
I thought you were just going on about the 'Snow Flake' icon cycling on and off on the center display.
You Aussie Volt owners need to demand a decent climate control system.
The NA Volts seem to work without 'cooler waves'.

What happens if you tape a tissue over the display so you can't see the 'snow flake'?
Nice try with tape over the snow flake :)
That is treating the side effect like me with the B160 Windscreen Temperature and Inside Moisture Sensor wire for humidity GY/L-BU Circuit 7564 located under the Review mirror mount to get the right fake voltage to the K33 Module.
The Humidity (& Rest of the HVAC) is totally over complex and over engineered which would not be an issue had some at GM of the HVAC engineers responsible checked it's actual operation vs what they thought they programmed. My proposed fix will not work as it would then prevent future defog operation / humidity control when needed.
It is all reliant on the K33 HVAC module and would be a truly great thing if engineered and programmed correctly!

I've been fortunate to have a few 12°C mornings here in Summer and did some testing. The cycling of A/C is less in ECO and worst in max - even with the temp setting at max Hi.

In an old fashioned system the momentary cycling of the A/C is a real big no no.. usually a mis location of the evaporator ice sensor which needs to be relocated or the sensor adjusted - they were mechanical type - could be "tuned" to avoid rapid cycling.

Fast forward to the VOLT all high tech with electronic sensors monitoring of windscreen humidity & temp.
The system has a Electric driven Compressor along with pipe gas valves it can switch... Main battery and or cabin HVAC.
Momentary switching on /off or short cycles is really not the best for long life - it will take it but will shorten the systems components life.

Besides the above the main issue is running the A/C - reduces heating output. So if conditions permit it should allow the heater to run flat out with no interruption from the A/C system.

I think the programmers of the K33 made the humidity reduction operation too sensitive (basically over specified it to keep too much of a tight control % wise) and they FORGOT to consult with the A/C designers to really TUNE the system.

I hope GM will revisit this and tune up the software in the K33 HVAC module, but if I know GM they are onto new and brighter models - so it will be a surprise if and when they do get back to this.

Lets hope a guy from one the A/C teams at GM owns a first gen volt and can see the operation resulting is not what would have been intended.

Fingers crossed.

Cheers, Martin
 

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Martin,
Do other Aussies complain about this feeling you get from the climate control system? I seriously doubt there is different Climate Control SW downunda. What if you took someone else and covered the 'snow flake' icon and didn't talk about it? Would they feel it? Do you know another Volt owner to compare with?

Maybe your particular car has a problem? For $65k you should be happy and not have to hack a car this complicated and expensive.
You do have 'Auto Defog' configured to OFF, correct?
I missed the part if you still have warranty. If not, I find that smiles and donuts help a lot with the service writers and techs !:)

Just a few notes:

>The AC compressor has it's own HV DC cables running to it direct from the HV battery. It has its own internal inverter and its motor is a 3ph AC, multi-speed affair. You can hear it ramp up in RPM. I doubt cycling has any effect on life. It's very energy efficient. And, as you know, the heat is not.

> The AC freon circuit runs in series through the cabin cooling evaporator and the 'freon to coolant' heat exchanger for battery TMS cooling of the HV battery. Even with just cabin Fan only running you will feel those 'waves of cool air' coming out the vents if the TMS needs to lower the HV battery temp.

>Maybe your TMS is asking for more battery cooling than is actually needed, (or not). You don't want to hack into that system. That's what makes GM EV's so great!

Sure, late model Leaf's have a 'Heat Pump' for cabin heating and cooling.
Do you know what they have for their HV Battery TMS? Nothing. Diddly.:(
 

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Discussion Starter #13 (Edited)
Hi Norton,

Yes other Volts are similar here that I know of and others are worse because they have not had the heater update software I found this thanks to this great forum - so yes that is a smiley :)

Yes Auto defog is off, so it is only attempting to balance cabin humidity (I hope)

Correct every Brand of EV's has its strong points and weak points....

GM volt 1's excellent points are: :)

  • Battery pampered beyond belief = excellent life and can handle HOT climates.
  • Great quite ride, smooth stress free balanced handling considering the weight of battery onboard.
  • One pedal driving in L is absolutely sensational.
  • Regen down to a very low speed.
  • Excellent reliability and performance of all the really high tech powertrain complex parts of the car.
  • Very good electric power steering including feel.
  • Very good brakes and pedal feel with my one having really sweet transition from regen to mechanical.
  • Design wise looks great like a very good hatch / car (unlike other brands that have gone the Weird look for their EV's)
Bad points are::D
  • Cabin heating use of water heating element vs a heat pump and what appears it really still needs fine tunning on the software parameters / settings it appears.
  • Tail & Head light venting (moisture water ingress if washed only slightly a little too aggressively)
  • Some internal trim parts needing rework for noise
  • Made to be assembled not for ease of service (most modern cars can compete on this front as they copy each others cost reduction innovations promptly)
  • Love of driving in L one pedal is damped a little by the need to select D to avoid being rammed from behind from other local drivers not paying attention of you slowing down on regen.
  • Scapping of lower air deflector on driveways, speed humps and even dips in roads (Not an issue for EV fans, just gives a cheap impression to passengers who don't understand why the need for the low slung air deflector making noises)
  • Not able to open windows while enjoying a quite ride without wind buffeting (Unless you fit the special weird looking mirrors to fix this issue) * Note some areas of the world you would not want to have windows open for personal safety reasons - but not all places in the world have reached this stage of concern yet :) thank goodness.
For comparison, Toyota have only come close with the build quality and drive - only just now with the 2016 Prius - however it is NOT a plug in. Only a Hybrid , The Old plug in Prius - every owner wishes they had the drive feel & low NVH levels of the VOLT.

The Leaf is limited by range and definitely does not like hot climates for battery life (recently they improved)

The BMW's the little one I3 is very small and glued together with a short gas range, the halo I8 is unaffordable as per current Tesla... will be interesting when they roll out the model III as the mass produced peoples car. Looking forward to this as Tesla for such a young company has done amazing things to transform the purchasing experience through to servicing and auto downloaded software updates that leave the old school companies in shock at being stuck in the mud of bureaucracy.

Looking forward to more EV's and the competition so each manufacture is encouraged to improve their EV's
It will be an electric future. :cool:
But I still may be tempted by one last proper drivers ICE powered 2 seater sports car yet ..... before the worlds gas supplies run low!;)
 
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