Angela Chao accident

[beatle]

Correct, the 12v systems remain online even after the loop is cut, but in order for the DC-DC converter to have any input on the HV side, the HV contacts need to be closed, and for that to happen, the contacts need voltage from the 12v. If the fireman's loop is disconnected, the 12v cannot close the contacts which isolates the HV battery. I don't think the DC-DC can operate independently to power the 12v systems function even if the 12v battery is taken out of service while the car is on.

https://www.tesla.com/sites/default/files/downloads/2016_Model_X_Emergency_Response_Guide_en.pdf

From that doc:

When cut, the First Responder Loop disables 12V power going to the airbag circuit. Cutting of the First Responder Loop also removes 12V power going to the high voltage contactors inside the HV battery pack. Cutting the first responder loop does not disable the 12V battery system. The 12V battery negative cable must be cut in order to disable the 12V battery system.

...

When necessary, the negative battery cable should be double cut to open the 12V battery circuit. Care should always be taken to not make contact with the positive and negative battery terminals when double cutting the negative battery cable. In addition to the high voltage system, Model X has a low voltage electrical system. Its 12Vbattery operates the SRS, airbags, windows, door locks, touchscreen, and interior and exterior lights. The DC-DC converter in the high voltage system charges the 12V battery, and the 12V battery supplies power to the high voltage contactors, allowing high voltage current to flow into and out of the high voltage battery.

 

[Daniel in SD]

I don't think the DC-DC can operate independently to power the 12v systems function even if the 12v battery is taken out of service while the car is on.

But that would mean if you had a 12V battery open circuit failure while driving the car would lose power steering. Tempted to test this since I can't find a definitive answer.

 

[beatle]

But that would mean if you had a 12V battery open circuit failure while driving the car would lose power steering. Tempted to test this since I can't find a definitive answer.

It would be a good test. When the 12v battery starts to die of "natural causes," the car warns you that it "may not restart." I think it would be a lot more disastrous and a bigger design fault if a relatively innocous 12v failure caused the entire car to die in the middle of a drive, so I guess these situations may not be as black and white as the emergency doc calls out.

 

[AlanSubie4Life]

But that would mean if you had a 12V battery open circuit failure while driving the car would lose power steering. Tempted to test this since I can't find a definitive answer.

Someone here claims to have tested it (though doesn’t sound like they drove, if you look around (even in that thread), you might find someone who has).

My M3 died while driving it and Tesla does not have a 12V in stock to fix it

 

[stopcrazypp]

It would be a good test. When the 12v battery starts to die of "natural causes," the car warns you that it "may not restart." I think it would be a lot more disastrous and a bigger design fault if a relatively innocous 12v failure caused the entire car to die in the middle of a drive, so I guess these situations may not be as black and white as the emergency doc calls out.

As you point out yourself, in the later updates, the car can still operate with a dead 12V battery by keeping the car awake, a mechanism to prevent the owner from being stranded. As such I would presume disconnecting the 12V battery with the car awake will not throw open the contactor, given there is still 12V on the bus from the PCS.

The main difference is as the warning goes, if the car is allowed to sleep (thus throwing open the contactors), it may not longer be able to wake, due to no 12V from the battery (and PCS already shut down).

And from your description, the fireman loop has two connections: one for the HV and one for the 12V battery. That indicates they are not one and the same.

 

[Just a Reader]

Wasn't it possible for her to roll down the side window and to escape the car that way?

 

[CyberGus]

Wasn't it possible for her to roll down the side window and to escape the car that way?

I assume that the low-voltage system would fail after being completely submersed.

 

[stopcrazypp]

I assume that the low-voltage system would fail after being completely submersed.

When top gear tried it, the window switches already failed even when partially submerged. Probably the water shorted them out, making them useless. The best policy is to immediately try to open the doors with the manual handle while the water level is still relatively low.

 

[fholbert]

Sheriff’s office: Shipping CEO Angela Chao, Mitch McConnell’s sister-in-law, was intoxicated at time of fatal car accident​

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www.cnn.com

 

[Zythryn]

Interesting that the “rear door” was open.
The report states that the driver couldn’t be reached/found through the rear door. I suspect they mean the tailgate and not a rear passenger/driver door.

.23 blood alcohol level is quite high. The video of her stumble on the way to the car combined with the blood alcohol level is pretty damming.

 

[stopcrazypp]

Sheriff’s office: Shipping CEO Angela Chao, Mitch McConnell’s sister-in-law, was intoxicated at time of fatal car accident​

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www.cnn.com

The article mentioned:
"The report said they attempted to break the front windshield but could not, eventually breaking the driver-side window.
Once the window was broken, the deputy stated they swam down and felt a hand, which, with the help of a medic, pulled Chao out of the submerged vehicle, which had been in the water for approximately 21 minutes."

That solves the mystery, given the driver side window was successfully broken, that confirms it's a 2020 Model X as originally claimed. The initial account about laminated glass misled everyone. Trying to break the windshield is a waste of time as all of them are laminated. I wonder who directed to try that.

 

[primedive]

In the video with Hammond, it was already very difficult for him to escape, and this was 15 years ago. Imagine if the car was one of the new ones with laminated windows all around. It's also not a given that someone would be 100% in a right state of mind after crashing their car.

Look beyond blaming the victim in this particular circumstance or immediately jumping to defending Tesla, as this problem is beyond that. Are we supposed to start carrying a portable grinder (and not in the glovebox that will be locked if the electronics die)? I get the safety side of it, but at the same time, the cars should not be this hard to escape.

 

[sllowsteady]

It's hard to imagine making a mistake with the stalk. Move your hand up for reverse and down for drive, just like every car in the world.

 

[CyberGus]

It's hard to imagine making a mistake with the stalk. Move your hand up for reverse and down for drive, just like every car in the world.

I doubt she was confused about which direction to swipe. She probably swiped in the correct direction but took her eyes off the screen while doing so and missed the target area.

I like stalks, they have tactile feedback. But it's still possible to short-stroke a physical lever/button when not being diligent.

 

[stopcrazypp]

It's hard to imagine making a mistake with the stalk. Move your hand up for reverse and down for drive, just like every car in the world.

Yet there are people that complain they got confused and expect up to go forward and down to go to reverse. Also it's possible to try to toggle that stalk, but not wait for it ot register and then assume it already registered when it didn't. Of the few NHTSA complaints on the shifting, there are ones where it's complaining about the stalk. Keep in mind also she was very drunk.

I doubt she was confused about which direction to swipe. She probably swiped in the correct direction but took her eyes off the screen while doing so and missed the target area.

I like stalks, they have tactile feedback. But it's still possible to short-stroke a physical lever/button when not being diligent.

There is no evidence the touchscreen shift system was what she used. The initial WSJ article suggested it was a 2020 (which had stalks), later articles pointed out they were able to break the side windows, which also suggests an older model.

 

[SwedishAdvocate]

Mechanical release or not, car doors are very difficult to open when submerged, even only partially.

Haven't read the entire thread, so apologies if this has already been posted. And this is a crossposting. But because it's relevant to this thread as well:...

I have a feeling it would be a good thing if more people knew that you can probably escape through the windscreen in an MX by using your legs and feet...

 

[kpanda17]

I agree, hard to promote negative possibilities when there is a death that seemed innocent
but should be considered negligent, feel real bad for the parentless child that now exists

hope we all know by now, human reaction to feel tragedy for her, more the child, and then it comes out as expected, she was an on-property DWI
how negligent as the father died a few years earlier leaving a young child with no parents

 

[primedive]

Haven't read the entire thread, so apologies if this has already been posted. And this is a crossposting. But because it's relevant to this thread as well:...

I have a feeling it would be a good thing if more people knew that you can probably escape through the windscreen in an MX by using your legs and feet...

I didn't think this was possible but it makes sense. Anyone willing to sacrifice a Tesla windshield for testing this?

 

[ev_go123]

Yet there are people that complain they got confused and expect up to go forward and down to go to reverse. Also it's possible to try to toggle that stalk, but not wait for it ot register and then assume it already registered when it didn't. Of the few NHTSA complaints on the shifting, there are ones where it's complaining about the stalk. Keep in mind also she was very drunk.

There is no evidence the touchscreen shift system was what she used. The initial WSJ article suggested it was a 2020 (which had stalks), later articles pointed out they were able to break the side windows, which also suggests an older model.

Right, sounds like a 2020 with stalks. And also sounds like it was more steering error and lack of stopping (and drunk error) rather than the wrong gear.
"The report stated that the camera then captured the car lurching toward a wooden barrier, reversing, turning to the left without stopping, and over the top of the limestone block wall."

 

[SwedishAdvocate]

I didn't think this was possible but it makes sense. Anyone willing to sacrifice a Tesla windshield for testing this?

As long as the windshield isn't covered with water... If the car is submerged I guess you have to wait until the entire car interior fills with water as well and then try to get out through a door by using the mechanical emergency door release. When submerged the door is probably easier than the front windscreen.