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Discussion Starter #1
I was driving a week ago and had barely used up much of my charge. I parked and went into a store, came out, started up and went home. I did not put the car into hold mode, but the ICE came on by itself! All of a sudden, I heard the engine running and wondered why...I had only used about 10% of my total charge. I don't remember if it was in hold mode or not, but I cycled it back to normal and all was fine. It was about 55 degrees outside, and I know the car was not refreshing the gas in the tank...I had exceeded the charge a couple of days before that and had been running on gas.

Was this just a glitch, or is this a known issue that other people have experienced? The car put itself into gas mode despite an almost full charge. There were no error messages on the screen.
 

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EMM (engine maintenance mode) lasts about 15 minutes. Perhaps a couple of days ago the engine did not get a full 15 mins of use and was just re-running EMM??
 

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open and re-close the hood

Car decided to make sure EMM worked as you never needed it :)
 

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Discussion Starter #7
So, if I was in hold mode, I did not put it into hold mode; it went there all by itself. I've never driven in sport mode. The hood has not been opened in about 4 months. The outside temperature was reading correctly on the display...but maybe the thermostat is what caused it to happen. I can't think of any other logical reason for this to occur, I will keep my eye on it to see if it happens again. Judging from the lack of response, it doesn't seem like anybody else has experienced this problem.
 

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So, if I was in hold mode, I did not put it into hold mode; it went there all by itself. I've never driven in sport mode. The hood has not been opened in about 4 months. The outside temperature was reading correctly on the display...but maybe the thermostat is what caused it to happen. I can't think of any other logical reason for this to occur, I will keep my eye on it to see if it happens again. Judging from the lack of response, it doesn't seem like anybody else has experienced this problem.
Bad hood sensor switch? ERDTT would run the engine for maybe 10 minutes and then switch to battery again, so even if it was the outside temp sensor, it would not stay on.

That reminds me, time to install my ERDTT defeat sensor before the weather gets awful.
 

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"The hood has not been opened in about 4 months."

because the match stick was still there ? or do gen2 now have hood open counters :)
 

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I've had my engine turn on randomly once as well. Temperature was probably mid 80's, i was in regular battery mode and driving around town. Definitely wasn't EMM as i had just got back from a two tank trip a few days prior. It ran for probably 2 or 3 minutes then went back to battery.
 

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Page 177 in the manual:

There are some conditions when the battery charge is high enough to provide Electric Mode operation, but the engine still runs. They are:
  • Cold ambient temperatures
  • Hot or cold high voltage battery temperatures
  • The hood being open or not completely closed and latched
  • Certain high voltage battery fault conditions
  • Engine Maintenance Mode or Fuel Maintenance Mode being run
 

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Discussion Starter #12
As already noted in my earlier posts, this was not due to outside temperature extremes, hood not securely latched (it had not been opened in awhile and was secure) or EMM. However, not sure about what "certain high voltage battery fault conditions" are...and if that occurred, wouldn't there have been an error message generated? There were no error messages.
 

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I think there is a condition that is not mentioned. The ONE time I put gas in my 2017 in the past year, the engine ran for a minute or two after I added gas. I figured it just wanted to circulate the new gas. I don't know what sets that off. It might be gas level in the tank, the opening of the gas door, tank pressurization, or something else. If it just senses the level of gas in the tank, what if you were parked on a hill and it senses a gas level change which triggered the 1 or 2 minute ICE run?

If you run on gas a lot, I'd suggest taking off the gas cap and putting it back on. Maybe it's not tight.

Just a thought.

Mike
 

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If it does not repeat, I would not worry about it. These cars are complicated enough that glitches happen sometimes. Like maybe the GPS stops working or the center screen reboots while driving. Usually restarting the car clears theses things. If it doesn't happen again, then it was probably a glitch. If it repeats, you can have your dealer check it out. They can scan for stored trouble codes.
 

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I'd open the hood to check the squirrels haven't been busy! I mean 4 months, you should at least check it once a month to note the fluid levels.
 

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On my last long drive, the ICE started and stopped on its own a couple of times in Normal mode. In 70 miles I used 30 miles on electric power and 40 on gas and still had some battery left. First time it has done this. It has started and alerted me of "Engine Maintenance" before. There was no alert for this. It was a bit cold but not that cold. The hood hasn't been opened in months. No errors were shown. I am curious to see if it does it again. Kind of makes me mad to be burning gas when i could be using electricity.
 

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On my last long drive, the ICE started and stopped on its own a couple of times in Normal mode. In 70 miles I used 30 miles on electric power and 40 on gas and still had some battery left. First time it has done this. It has started and alerted me of "Engine Maintenance" before. There was no alert for this. It was a bit cold but not that cold. The hood hasn't been opened in months. No errors were shown. I am curious to see if it does it again. Kind of makes me mad to be burning gas when i could be using electricity.
How cold is a bit cold? If it was lower than 35F the gas engine will start (unless Engine Assist Heat is set to Deferred), then cycle on and off to maintain the engine coolant between 120F and 140F for cabin heat. The message Engine Running Due to Temperature (ERDTT) will briefly appear the first time the gas engine starts but if you miss this message it does not repeat.
 

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How cold is a bit cold? If it was lower than 35F the gas engine will start (unless Engine Assist Heat is set to Deferred), then cycle on and off to maintain the engine coolant between 120F and 140F for cabin heat. The message Engine Running Due to Temperature (ERDTT) will briefly appear the first time the gas engine starts but if you miss this message it does not repeat.
That's the most likely explanation. cougsfan, was the Engine Assist Heat set to normal or deferred?
 

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Discussion Starter #19 (Edited)
I am careful to tighten the gas cap fully, so it wasn't that. The problem has not occurred again, so it was probably a glitch. I doubt there has been any squirrel activity, I park in a garage...but I probably should open the hood more often to check things.
 

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That's the most likely explanation. cougsfan, was the Engine Assist Heat set to normal or deferred?
It was around 40 degrees. I am not sure how you tell if it is set to normal; or deferred Engine Assist heat. Does that mean is the "Max" or "Econ" mode is selected? Does "Max" cause the ICE to start?
 
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