Volt Engine Operation in Cold Ambient Temperatures

[scottf200]

Nice describe with some details from a GM Techlink article: http://www.sandyblogs.com/techlink/J...chlink%20F.pdf

Volt Engine Operation in Cold Ambient Temperatures

Volt owners may notice that during a cabin conditioning (remote start) event in cold ambient temperatures, the internal combustion engine (ICE) runs even with the vehicle plugged into a charger. Owners may also note that while driving in cold ambient temperature the ICE will run for extended periods or cycle on and off. A message will display on the instrument cluster that states ENGINE RUNNING DUE TO TEMPERATURE. This may occur even when the battery is fully charged. No DTCs will be associated with this condition.

At ambient temperatures of approximately 25° F (–4° C) or below, the ICE will operate to assist in warming the coolant used to warm the vehicle’s cabin. After the coolant temperature reaches approximately 150° F (65° C), the ICE will turn off and remain off (as long as the battery state of charge is sufficient) until the engine coolant temperature drops to approximately 104° F (40° C), at which time the ICE will restart. This function will continue as long as the ambient temperature is approximately 25° F (–4° C) or less while driving. After the ambient temperature rises above approximately 25° F (–4° C), the vehicle will resume normal electric operation (as long as the battery state of charge is sufficient).

This is normal operation and no repairs should be made to correct this condition.

[UPDATE]
You typically can limit your Engine Running Due to Low Temp ERDTLT by using COMFORT and low fan settings (1,2,3).
See: COMFORT-setting-limiting-quot-Engine-Running-due-to-low-temperature-quot-ERDTLT
http://gm-volt.com/forum/showthread....re-quot-ERDTLT
[/UPDATE]

[UPDATE]
Late 2012s have a Very Cold config option that changes the temp from 25F to 14F. Hardware change.
Update: Response from ari_c's Volt Advisor

The difference for this feature is actually in the hardware itself, because the heating system is designed differently. Unfortunately there is not an upgrade for the engine assisted heating options, but if this changes in the future we'd be happy to let you know.

[/UPDATE]

[therfman]

I wonder if the electric heater works during this cycle. Once the ICE has bought the coolant temp up to 65C, does the electric heater turn on to at least try to keep the coolant warm despite the cold ambient temps? If the only thing providing heat is the on/off cycle of the ICE, I'm afraid the Volt won't be much of an EV for me in winter; during the months of January and February, it's unusual for the temperature to ever climb above -4C, day or night.

[maestro77]

I'm wondering the same thing.....
SURELY the high voltage battery will do it's very best to keep the cabin-heating-coolant adequately warm during the time period the ICE has cycled off.
However, can anyone with specific knowledge (rather than just guesses) comment??

[Slapshot28]

I'm not sure if this will help, but it is written by our definitive Volt expert (WOP) and has quite a bit of detail:

http://gm-volt.com/2010/12/09/the-ch...ems-explained/

Check out the comments below the article as well, because WOP provides an adiitional schematic at Comment #36.

[maestro77]

Thanks Slapshot28,
The third block diagram does seem to indicate a 360V Electric Heater is in series with the direction of flow of coolant from the ICE to the Cabin Heater Core. And that even more specifically there is a bypass coolant loop recirculating coolant from the Electric Heater specifically to the Cabin Heater Core "During EV Operation".

[BlackVolt]

I understand the ICE will start at 25° F (–4° C) but what about in very hot temperatures? The owners manual advises the ICE may start due to temperature of either hot or cold ambient temperature. Does anyone know the answer at what hot temperature will the ICE start?

[solar_dave]

We have driven ours in 115F temps and the ICE has not come on. But it is generally plugged in when not in use and does make a power draw every few hours, I assume to condition the battery, and when driven the AC is at least on in ECO mode.

[BlackVolt]

We have driven ours in 115F temps and the ICE has not come on. But it is generally plugged in when not in use and does make a power draw every few hours, I assume to condition the battery, and when driven the AC is at least on in ECO mode.

That's interesting. I wonder what would happen if the Volt was not plugged in and was sitting in a hot parking lot at this temperature. I wonder if the ICE would start to help with the cooling of the battery etc. There must be a threshold for the ICE to start in hot temperatures. I wonder if Rusty or any of those guys have an input to this.

[bluelight_tj]

It was my understanding that the volt will circulate collant to help to maintain a certain range of temp for the battery. I know if plugged in to power it draws from there. If not i would think it would draw from the battery. Not sure what would happen if the battery was depleted though. From what i have heard owners have comment to hearing humms and noises from the car which are normal as the pumps kick on and off at night.

[Roadburner440]

The car certaintly makes some odd noises.. Especially when plugged in. The night we brought ours home, and hooked it up to the charger I unplugged it as it almost sounded like a bug zapper going off.. I have now just come to accept it as normal as everything is always fine when I go out in the morning. Can also occassionally here a pump come on and go off. As far as in the heat we have had some pretty hot days here in Florida, and to my knowledge the engine has not kicked on because it was to hot... Curious to see how the cold weather operations are since we will be moving to Virginia in 2 months..