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When is car on or off? What makes it turn on/off?

jimbo69ny

Member
May 12, 2018
403
183
Ithaca NY
Hey guys,

Im new to Tesla and I have a brand new Model X that I have owned for a week.

I am wondering if you could shed some light onto what needs to happen for the car to be on or off. I know that sounds like a vague question.... Let me clarify,

I am specifically wondering about when the battery contactors are closed. If you follow my youtube channel you might know what I am getting at lol.

I did a little testing today and the car seems to need to sense a body in the drivers seat AND the drivers door closed in order for the car to be ON and ready to drive. (this is also when the battery contactors would be closed).

I tried to leave my key inside the car hoping it would leave the car on and contactors closed but it didnt. It seems as though the car is only ON when door is closed w/body in drivers seat or while charging.

Are there any other tricks you have seen that keep the car ON? I really thought leaving the key inside the car would do it but I was wrong.
 

ajdelange

Active Member
Dec 10, 2018
1,077
638
Virginia/Quebec
Good question and I wish I could answer it but it's still pretty sketchy to me. The car seems to have 3 states: 1)Asleep 2)Idle and 3) On. When it is asleep I assume the contactors are open most of the time as there is no or miniscule vampire drain reported for those periods. There is still stuff going on when the car is asleep as you can, for example, wake it up to blow the horn or flash the lights or get a reading of the battery status. All the energy required for those functions comes from the 12V battery whose status is monitored in sleep mode such that if it becomes discharged the contactors close and the DC/DC converter charges it.

Anything that "pings" your car wakes it up e.g. if Tesla wants to talk to it (in response to a request from you through the app for a charge status check) or you use TeslaFi or Stats or another app to help you manage your car. As a new owner you really should look into those as they are very handy way of keeping logs of your charging and travel. But keep in mind that if you use them they will ping your car for status thus increasing vampire drain.

It is now 8 hrs and 30 minutes into the day and TeslaFi tells me my car has slept 4 times for a total of 2:19 and idled 4 times for a total of 6:07 which has cost me 0.9 kWh in vampire drain.

Hope you are having a ball with your new toy!

Just noticed your location. I recall that one of the local DJ's there once said "We have three seasons in Ithaca: July, August and winter." You'll soon be learning about the effects of hills and cold weather on a BEV.
 
Last edited:

ewoodrick

Well-Known Member
Apr 13, 2018
5,285
4,282
Buford, GA
I think you may be trying to make rules that don't exist.
The computers tend to be on or asleep, no off.
The big battery can be connected or disconnected, but that doesn't mean much. If it realizes that the 12V battery is low, it will engage and charge.

On and off is a legacy concept and doesn't really apply to modern computing
 

jimbo69ny

Member
May 12, 2018
403
183
Ithaca NY
I think you may be trying to make rules that don't exist.
The computers tend to be on or asleep, no off.
The big battery can be connected or disconnected, but that doesn't mean much. If it realizes that the 12V battery is low, it will engage and charge.

On and off is a legacy concept and doesn't really apply to modern computing
I know I’m being vague but the contactors being on or off is everything in my current project.
 

Saghost

Well-Known Member
Oct 9, 2013
8,224
7,087
Delaware
The dash display said “car off” as soon as I got out of the car, closed the door with the climate on. The contactors might be closed in that situation but I’ll have to check the Can data to find out

Yup. We knew that would happen. Car off as in, can't be put in gear and driven by someone knocking the stalk.

I don't think that version of off has anything to do with the status you're looking for.
 

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