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Dear fellow Volt owners, and prospective owners,

GM did announce that the infamous ERDTT (Engine Running Du To Temperature) - only used to provide cabin heat - will be back in the 2016 Volt. In northern countries, the use of ERDTT makes the Volt highly inefficient in short trips, even just to move the car out of the driveway, and this causes an high level of insatisfaction about this poorly designed feature. Moreover, during short trips, the ICE engine is unable to get hot enough to remove condensation from oil. It can even be a factor for shorter ICE engine life in cold climates.

GM is even sued in a class action based on the fact that the Volt was portrayed as 100% electric when there is still energy in the battery. ERDTT of course prohibits this and this is one of the basis of this class action.

There is even a well-known modification to the exterior temperature sensor to better control the ERDTT.



More information is available from http://roulezelectrique.com/petition-a-propos-de-lerdtt-sur-la-chevrolet-volt-2/
In the above link there is a reference to an interview with Mr Andrew Farah, chief engineer of the Volt, that states that the ERDTT is only for cabin heat purpose.

A petition is ongoing to ask GM to provide a better control of the ERDTT to the driver. This can be as simple as a confirmation screen that is presented on the center console display, in an analogous matter to the EMM (Engine Maintenance Mode) screen.and the link to the petition is to: https://www.change.org/p/general-mo...ture-rendre-le-erdtt-une-fonction-optionnelle


The text of the petition is bilingual, English and French.

Thank you for supporting this matter and helping to make the Volt an even better car

Francois Boucher
B2653
 

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HAHAHAHAHA!

Maybe stage a sit in too.

GM, like everyone else manufactures a product. If you dont like it, dont buy it.

Petition..... Like GM gives a crap about a Petition. Shoot, Its silly whinning like this that stops companies from innovating new stuff.


Knock it off!
 

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You're probably right about that, but at least this one is though out a little better than most lately.
The sad part is this would literally take 30 seconds to add the code during development and likely would voilate no laws.

Sort of like having the ERDTT temperature selection available in the settings, this could be no different and setup to stop ERDTT in situations where the climate control is either
1. Off
2. Not set to defroster.
 

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Outside of this forum, I know no one with a Volt who cares at all about ERDTT.
 

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Outside of this forum, I know no one with a Volt who cares at all about ERDTT.
That doesn't necessarily mean that it shouldn't be implemented better. I signed the petition...sorry Elemental. :p
 

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I love ERDTT now that it can be adjusted to 15 degrees. I think it is one of the things that makes a Volt better than a Tesla or Leaf.
 

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I am ambivalent...

...I value availability of the range extender when I need it. If I didn't, I would not have purchased a Volt. I also understand that FMVSS requires some degree of window defogging under certain conditions. If it is better to meet those requirements by using the ICE rather than an electrically driven heater, then so be it. Yes, I don't like to waste gas. But it is no more than a tenth or a few tenths of gallons per day or per trip. The issue has been brought to GM's attention. I don't know what other issues GM's Volt team is dealing with, but I give them enough credit to intelligently set priorities...

...Moving on...

KNS
 

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Perhaps there should also be a petition to replace (or complement) the dumb resistive heater with a proper heat pump. Having said that, a little more control over ERDTT would be welcome, especially when the battery is full. Maybe they can make ERDTT a little more aggressive as the SOC goes below a certain state, giving the ICE a chance to provide some extra heat while preparing to switch to CS mode by lubing and warming itself ahead of time.
 

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This is a completely pointless exercise. We know that ERDTT is required by federal regulations governing the defroster, so, while the engineers will do their best to minimize it, you can't eliminate it. No doubt they could eliminate it by making the car less aerodynamic or something but short of that type of thing there isn't any way to do it.

I'll just note that Volvo engineers thought that the best way to make a BEV workable in cold weather was to add a fossil fuel heater. Be glad you have a great heater and think of ERDTT as the price you pay for living in cold places. (I've never experienced it even in a 2011 MY Volt). Personally I value safety over burning a little gas.
 

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This is a completely pointless exercise. We know that ERDTT is required by federal regulations governing the defroster, so, while the engineers will do their best to minimize it, you can't eliminate it. No doubt they could eliminate it by making the car less aerodynamic or something but short of that type of thing there isn't any way to do it.
I would argue they haven't done their best to minimize it though. For example, once the engine has heated the coolant after the first ERDTT cycle, the car could keep the coolant's temperature maintained with the resistive heater.

In 2011-2012 Volts, this is precisely what the system did, and you could essentially prevent additional ERDTT cycles by using Comfort and dialing down the fan speed a bit. The resistive heater was sufficient to maintain the coolant temperature above the setpoint that triggered subsequent ERDTT cycles.

In 2013 and newer, when ERDTT starts, after the engine has warmed up the coolant, the resistive heater goes off, and it does not turn back on. Instead, the engine keeps cycling. Effcient for trips that exceed the battery's range, but burns infintely more gas than necessary for trips that are less than the battery's range.
 

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Better than a Leaf, sure but certainly not even in the same league as the Tesla!:cool:
I can drive 300 miles non stop in my Volt in sub zero temps and not freeze my ass off. Show me a Tesla that can do that.
 

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Guess i'm in the minority on this one. I like ERDTT, and actually wish i could control it to come on at a higher temp or at will. At least with my daily route, being able to get heat from the ICE would extend my EV range noticeably.
 

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ERDTLT is my the one thing that annoys we the most with my Volt. I pre-condition my Volt twice in my garage and pull out and go 0.5 miles and bam ERDTLT comes on. WTF! The inside cabin is toasty warm and climate is off. Uhm GM engineers, I do not thing I need the engine to come on to heat an already warm cabin with the climate control off. ERTDLT is doing nothing but wasting gas in this instance. Please give the driver an option to disable! Short trips are very irritating when ERDTLT comes on. Really not needed for short trips. Shouldn't ERDTLT be based off inside cabin temperature anyway and not outside temperature?
 

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The sad part is this would literally take 30 seconds to add the code during development and likely would voilate no laws.

Sort of like having the ERDTT temperature selection available in the settings, this could be no different and setup to stop ERDTT in situations where the climate control is either
1. Off
2. Not set to defroster.
Not trying to start a fight, but I note that you did not include the software code GM can simply drop into place for this mod. Understandable because of course you have no idea of what the code is, nor how easy (or fast) it is to change. You have not acknowledged the time it will take to test the change under various conditions, which is wholly unrealistic. I note that you have also changed the way the code works by suggesting new options (which needs a new interface - more work and time and testing).

I always get a kick out of how minimal (30 seconds!) the effort is claimed to be when the person making the claim isn't the one doing it, has no understanding of the underlying code nor what ripples the change may make for related systems, nor how the change affects any certification requirements (if any), and does not take into account testing.

Hey, I'd like to see this change to. I'm with you. I've said so many times. But I am pretty sure this is more than a "30 seconds and done" exercise. Likely way, way more. But to your main point, not huge project either.

Guess i'm in the minority on this one. I like ERDTT, and actually wish i could control it to come on at a higher temp or at will. At least with my daily route, being able to get heat from the ICE would extend my EV range noticeably.
No, rmay635703 and I agree with you.
 

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Not trying to start a fight, but I note that you did not include the software code GM can simply drop into place for this mod. Understandable because of course you have no idea of what the code is, nor how easy (or fast) it is to change.
I do know code and it would be very simple to add a line to the configuration for Cold, extremely cold and never. I choose to not use heat so why do i need ERDTT???

Needless to say I signed the petition.

The problem is I think this is governed. From what we are told there are regulations as to how fast a windshield has to defrost. Without a heat pump i don't think the battery can deliver within specs of this so called regulation.
 
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