Leaving a hybrid on.

[Olyelr]

Hi all,

My daughter has a Maverick hybrid and drove to Chicago to visit her sister. Her sister used the truck and brought it back and parked it for 8 hours. When they went to leave the 12 volt battery was dead and needed a jump. As soon as the cable connections were complete, the I.c.e. Fired up.

The daughter who owns it thinks her sister left it “on” while placing in park and locking the doors. My question is, if that’s the case, wouldn’t the hvb maintain the 12 volt battery and starting the engine to keep the hvb up?
Thx
Andy

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[The Real Maverick]

Yes. You probably didn't see what you thought you saw.

What specifically makes you think the 12v battery was dead?

 

[The Real Maverick]

Not enough evidence provided in the posting. Example I assume the truck is Lariat but you didn't say.

Also was the engine already warm? You didn't say.

Was the truck far enough away from the house that no one would notice it run once in a while? Like 2 minutes every 45 minutes the whole night?

 

[Olyelr]

Sorry for the incomplete post. It is a 2023 Lariat and the engine was warm. It was parked in front of an apartment building and the sister lives on the 6th floor so they would not of noticed it turning on.

When they went to leave the fob would not open locks, no lights etc. Had to use fob key to get in the door and everything was dark. Hooked up jumper cables. As soon as second connection was mad, the I.c.e. Started.

What is normal behavior for a hybrid? If you put it in park and engine is off and you don’t hit the push button start/stop again to turn it off, what would the truck do? Should it maintain the 12 volt battery until the hvb needs charging and it would start the ice to maintain it?

thx Andy

 

[CurtisB]

Well..................I think 100's of us already know the answer. I'll start with the first question. Do you have the original 12v battery that came with your Maverick?

 

[acelee1895]

Sorry for the incomplete post. It is a 2023 Lariat and the engine was warm. It was parked in front of an apartment building and the sister lives on the 6th floor so they would not of noticed it turning on.

When they went to leave the fob would not open locks, no lights etc. Had to use fob key to get in the door and everything was dark. Hooked up jumper cables. As soon as second connection was mad, the I.c.e. Started.

What is normal behavior for a hybrid? If you put it in park and engine is off and you don’t hit the push button start/stop again to turn it off, what would the truck do? Should it maintain the 12 volt battery until the hvb needs charging and it would start the ice to maintain it?

thx Andy

There is a default setting that shuts the truck off after 30 minutes of idling. There are two ways to turn it off, one is to use the steering wheel buttons to navigate to the menu settings on the dash screen and turn it off. The second way is if she already sat for 30 minutes in it, it will chime and say the truck is shutting off in 30 seconds if you don't click OK on the steering wheel.

She would have had to turn that off since it was last turned on for it to idle all night. It resets to auto shut off each time the ignition is cycled.

Now to under stand correctly, you said the battery was dead and the moment the jumper cable touched the battery terminal, the truck started? without anyone pushing the button? Thats a whole different issue. I have never heard of that and have done some pretty strange stuff with my 12v battery.

 

[The Real Maverick]

Hard to figure out without being there.

I would say the truck was "on" before they tried to "jumpstart" it. And by matter of coincidence the gas engine started just as the jumper cable was attached.

As for the keyfob not opening the doors it could be a coincidence also. Or weak keyfob battery. Or loose connection on the 12v battery. If loose intermittent 12v battery connection it could have been jostled back into making contact while fiddling with jumper cables. Did they attach under the seat or under the hood?

As for the 30 min rule mentioned above, my XLT is not like that. It will sit and idle for at least 2 hours and I did not consciously change any settings so???

 

[sundog]

Almost sounds like the driver pushed the start button after the car was off but not while pressing the brake, putting it in accessory mode. Easy mistake with you unbuckle first and an alert obscures the dash screen. Is it possible the info relayed about "engine fired up on its own" was missing a part about someone pushing the start button after the cables were connected?

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