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Discussion Starter #1
I am not the type to never want my engine to come on at all. I realize that burning a little gas can be more efficient than trying to use electricity to get the cabin comfortable when it's less than 20 degrees outside. On most occasions, I view this as a benefit of owning a PHEV, not a hindrance.

However, I've noticed recently that under about 17 degrees Fahrenheit, the engine will come on no matter what and run constantly for about 10 minutes (as opposed to on and off hybrid operation in hold mode), until the coolant temp gets up to about 180. During this cycle, it consumes about 0.20 gallon of gas according to the energy display, and I usually end up recording about 10-20 MPGcs on short trips.

Again, I have no problem with this if it's used to "kick start" the heat on a half hour or longer trip, but if I'm running 10 minutes down the road to grab bagels or go to the hardware store or whatever, I feel like I'm running the gas to heat up the cabin on a trip that's not even long enough to heat it, and by the time I get done with my errand, my cabin is cool again and the engine runs due to temperature again while I'm driving home.

By the time I get home, I've burned between 0.2-0.4 gallons of gas over just 5-10 miles total, I didn't drive long enough either way to really benefit from the heat, and my miles per gallon score is awful.

My engine assist heat setting is already on deferred. I realize this is small potatoes in the grand scheme of owning the Volt, but I feel like I should be able to tell the car "no, don't do this, I'm happy enough being cold for the next 5 minutes of my life." Frankly, it's odd to me that this setting runs even before I turn the heat on.

Any suggestions -- I'm not looking to tear my car apart and install a defeat device. Just wondering if there's something I can do to sort of trick the Volt out of ERDTT mode when I'm taking a short trip.
 

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That is a very common complaint of owners, and the fix is to install a defeat device, which is a resistor, in place of the outside temperature sensor. There are a lot of threads about that. Search ERDTT defeat, or look at the list of similar threads at the bottom of the screen.
 

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Discussion Starter #3
Thanks, Barry. I've seen a lot of those threads. I'd prefer not to completely disable the exterior thermometer sensor and was hoping for some kind of "↑↑↓↓←→←→BA Start" cheat code that was some combination of climate and drive mode adjustments that could trick the Volt out of engine assisted heating. I still want the engine assist to happen when it is super cold and I am driving to work or further.

Probably doesn't exist but always worth a shot on these boards.
 

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Sorry, no cheat code that I have ever heard of. Some members have come up with some pretty ingenious defeats, but they all require some hacking.
 

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There is this pretty nice device on ebay that auto activates when the temp is below 15 and deactivates when not needed so it gives an accurate temp reading. It is a bit expensive but its plug and play. Otherwise a resistor will work fine but you would have to manually add it and remove it as desired.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/283266406735
Yes, that's made and sold by one of our Canadian GM-Volt members. I think he has a version with a manual toggle switch as well (open hood, switch on/off, close hood).

I bought an OEM sensor (~$6) and added a 39k Ohm 1/8watt resistor ($5 for 6) to it. I replace my original air temp sensor with it in November. I take it out in spring. No more backing out of my heated garage with a full battery only to have the gas engine start 15 feet down my driveway, or 3 more times by the time I get to the store and back with almost a full battery. If I want heat, I have plenty from the battery. If the battery is half drained, I can run Mountain mode (no Hold on a 2011) to get gas engine heat.

BTW, the electric heater on my BOLT EV rocks. Very fast, very hot. Beats an ICE or my Volt.

P.S. Another member, lug_nuts wired up his defeat inside the cabin, under the front passenger seat. More convenient (but a bit more complicated installation).

And then there is another option using an OBD2 hack. See https://gm-volt.com/forum/showthrea...ld-app-can-defeat-ERDTT&p=4648197#post4648197
 

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The 2019's have a lower 'deferral' setting for ERDTT. I have it on the lowest and the engine doesn't run in our current below zero temps. I'm a 'car guy' with mechanical knowledge and it appears that GM thought about most of the pitfalls with the engine and how it's used. I feel that occasionally starting the engine for a few minutes isn't the best use of it. I'm trying to plan ahead and run in Hold mode once in awhile, even before EMM triggers.
 

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Last winter I came across a posting that stated that once the ICE heats the coolant up to temp and then cycles off, the coolant temp can be maintained by activating the max heat setting with a low fan speed. I have tried this procedure numerous times and it does seem to work. Unfortunately the initial engine start is still required but it does save all of the successive restart cycles during your trip. I am also in the camp that does not like to start up the engine for only a few minutes so I am strongly considering purchasing the defeat device.
 

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Last winter I came across a posting that stated that once the ICE heats the coolant up to temp and then cycles off, the coolant temp can be maintained by activating the max heat setting with a low fan speed. I have tried this procedure numerous times and it does seem to work. Unfortunately the initial engine start is still required but it does save all of the successive restart cycles during your trip. I am also in the camp that does not like to start up the engine for only a few minutes so I am strongly considering purchasing the defeat device.
I'll have to give that a try as my wife doesn't want me messing with what is mostly her car while it's still under warranty.

I may also try putting it in Hold mode while it's on ERDTT the first time to let the coolant temp max out, and get the engine nice and toasty. That too may help prevent additional ERDTT events.

We will have plenty of opportunities to try these tricks out over the next week or so here in Minnesota.

Sent from my SM-G930V using Tapatalk
 
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