[hallcp]

This is my first winter with an '18 Volt. This morning when I used the remote to initiate pre-heating I came out to find the ICE running. It continued running for some blocks, then cut off. Over the drive to work it came back on several times. The outside temperature is around 30-degrees, the battery was at 90% charge, and the engine coolant temperature ranged from 136-145 (roughly).

Does anyone know the logic the Gen2 Volt uses to determine when to run the ICE in cold weather?

Thanks!

Charles.

 

[Barry]

Any time it is below about 35 F, the engine will run intermittently just enough to heat the engine coolant fluid so your defroster will work well. This is not really necessary since there is an electric heater also that works pretty well. You can adjust a setting so that this will not happen until it gets colder (I think about 15F). You can also adjust a setting so this will never happen while plugged in (preconditioning).

This feature is called ERDTT or Engine Run due to temperature.

 

[saghost]

This is my first winter with an '18 Volt. This morning when I used the remote to initiate pre-heating I came out to find the ICE running. It continued running for some blocks, then cut off. Over the drive to work it came back on several times. The outside temperature is around 30-degrees, the battery was at 90% charge, and the engine coolant temperature ranged from 136-145 (roughly).

Does anyone know the logic the Gen2 Volt uses to determine when to run the ICE in cold weather?

Thanks!

Charles.

I believe it's the same logic as Gen 1 - something bizarre and arbitrary that GM came up with.

You've just had your first encounter with ERDTT - Engine Running Due To Temperature, as the DIC part of the instrument panel used to display (probably still displays?) when it happens. (You'll find lots of threads on the topic if you search on our made up acronym.)

GM set it up so that when the outside air temperature goes below a certain value, the engine runs just enough to keep the coolant warm to deliver cabin heat - it comes on when preconditioning or when you start the car, runs until the coolant reaches ~150F, then shuts off until the coolant cools down and cycles again.

On later first generation Volts, it came on at 35F by default, but there were options in the center screen to change that to 15F and to disable it when preheating while plugged in. I suspect those options are still in the center console setup menus.

 

[BAZINGA]

The temp the ICE will cycle on/off can be set from 35 degrees down to 15. That's where I have mine set. It's in the Setting menu under Comfort and Convenience settings.

 

[alfon]

We have our 2016 Volt set at the low setting when the engine starts at below 15 F. There is no reason as my wife's 32 mile round trip to her business is always done with miles to spare on pure electric even when she has the heat on high. The electric heater works quite well but does use a lot more energy compared to the AC during summer months.

 

[Steverino]

There is a mod to the ERDTT (engine running due to temperature) where you place a resistor between the two legs of the outside air temperature sensor prongs. A member even sells a plug and play kit on ebay if you don't want to do it yourself.

See http://gm-volt.com/forum/showthread.php?127761-ERDTT-Modification-Options

 

[EricT]

You must live in a place that doesn't get cold often.

An ICE is a great heater. If you want to avoid frostbite, be happy that you have one when it is sub zero F.

 

[Arcanox]

Yeah, I deliberately leave ERDTT on the 32* setting unless I'm going to drive only a few miles (in which case I turn the car on in the garage, set it to "Deferred", restart the car, then leave). I eventually want to put in the "Engine Running Due To Driver" mod with two switches in the cabin, but that's a project for another time.

 

[begreen]

The temp the ICE will cycle on/off can be set from 35 degrees down to 15. That's where I have mine set. It's in the Setting menu under Comfort and Convenience settings.

I just checked our 2018 Volt and that setting is not listed there. The ICE is turning on at 36º and I don't want that.

 

[Steverino]

moved to Use, Care, Maintenance...

 

[obermd]

I just checked our 2018 Volt and that setting is not listed there. The ICE is turning on at 36º and I don't want that.

Page 139 of your owners manual. It's under Climate and Air Quality.

 

[begreen]

Page 139 of your owners manual. It's under Climate and Air Quality.

Thanks, I was looking for a literal temperature setting of 32º or 15º. I have since read that it is under Engine Assist Heat. I set it to deferred, but the engine still runs. This is not Engine Maintenance mode. There are no alerts or indications of why this is happening. I just posted more details in the ERDTT thread.

 

[begreen]

The thought is that this is Fuel Maintenance Mode. I had the same thought last night and watched the console screen, but did not see an alert for FMM. I will try again today. It is so annoying when the car is only going on 5-10 mile long trips.

 

[hellsop]

I don't know the Gen 2 behavior, but for Gen 1, the infotainment screen screen gets a notice (allowing deferral for one day), a notice that there's no option about it now on the first start of the second day, and both messages self-dismiss after a short time if ignored, after which the Volt starts the FMM. Once the FMM starts, there's no more message on either screen about it, it will just run CS until the tank is refilled while the car is off, no matter how many starts are involved before refilling. So theoretically, you could miss one message on the infotainment and not know FMM was happening. (I like to think I'm too observant for that to happen to me, but ... we all kid ourselves sometime.)