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Rear Doors - Safety Risk?

Rear Doors - Safety Risk?

So many of you probably saw the article posted with the review from Sandy Munro (https://www.teslarati.com/tesla-model-3-teardown-video-review/). While I agree most of it seem like biased and not worth worrying about, one thing has my family (mainly wife) concerned, the rear doors. Is it true there is no mechanical release for the rear doors? We have two small children and the concern is that in the event of an accident, the power would go out, and the kids would be unable to get out without crawling thru one of the front doors.

Is there any validity to this concern?

Is this really what would happen in a crash?

Looking forward to your input.

stevea137 | February 6, 2018

It is a valid concern. Only the front doors have mechanical door releases on the interior. If you are in an accident and the 12V power system fails, rear seat passengers will have to exit via the windows, front doors, or trunk. Children are likely small enough to easily crawl through the front seats to exit. Adults will probably have an easier time exiting via the windows or trunk (if the windows are closed or they can't break the windows).

FWIW, the S had a similar issue. There were mechanical door releases for the rear, but they were below the seats and not likely that a small child would be able to operate them on their own; instead requiring an adult to operate them somehow.

I think the best course of action is to keep an emergency glass punch/seat belt cutter on your key chain so once you exit you can pop the windows and pull rear passengers out (yea I know, M3 doesn't take a key, but you have to get back in your house somehow) .

stevea137 | February 6, 2018

Oh, and I will also add; losing 12V power in a crash isn't very likely since the 12V battery is located at the base of the windshield somewhat centrally and would take quite a crash to damage that area.

Also, if a crash causes the airbags to deploy, all the doors automatically unlock so, in theory, the door actuators should be able to open even without the central computer operational.

ReD eXiLe ms us | February 6, 2018

It is precisely because it is likely that the rear seat occupants would be children that there is no easy to reach quickly accessible mechanical emergency release on the rear doors.

Think about it for a minute.

Most Parents I know set the slider for a 'child safety latch' found on the inside door jamb of rear door panels so that the car cannot be opened from the inside anyway. And, in those cars, a broken exterior door handle will not allow the door to open from the outside either. So this is no more of a 'safety concern' for Model 3 than any other car.

[ YouTube -- tvfW_kuOSjE ]

"Most child car locks can be activated via a small switch on the edge of the door. ... Child safety locks tend to be built into the rear doors of most cars and are used to prevent rear seat passengers, particularly little ones, from opening the doors both during transit and while the vehicle is stationary."

http://www.theaa.ie/blog/how-to-activate-a-child-lock-in-your-car/

[ YouTube -- PJ7U5mpbJTY ]

Coastal Cruiser. | February 6, 2018

I believe ReD is correct. This topic has been beaten up pretty thoroughly lately, and although I too was apprehensive about no mechanical release on the back door at first, Tesla is effectively emulating traditional child safety locks in the back seat.

Having had the experience of a child opening a door and falling out of the car while I was backing up (2 miles per hr), to me the risks are higher when children have easy access to the door release.

Note too all the recent reports about how adults unfamiliar with how to open a Model 3 door are instinctively reaching for the mechanical latch.

stevea137 | February 7, 2018

The only flaw with the child safety lock argument is the exterior door handles on the M3 are not mechanical either; so if 12V power is lost, there is no way at all to open the read doors. Unlike all other child safety locked doors which can be opened from the outside (or opened by an adult if the window was rolled down).

it doesn't really concern me much; just wanted to mention it.

stevea137 | February 7, 2018

/s/read/rear

Shock | February 7, 2018

It's a valid concern.

It's also a trivial one.

Think about the exact variables that would all have to occur such that the car
1) loses power
2) is an emergency such that kids have to exit ASAP
3) Somehow despite losing power and being an emergency the doors themselves are not bent into the frame and, if not for the latch issue would freely work
4) These same kids cannot exit by crawling into the front where their parents have already left the car

The odds of this being relevant seem much smaller than being in a typical accident, and if the model 3 survives those as well as I suspect it might, the overall safety from impact far overshadows a rear latch issue.

hokiegir1 | February 7, 2018

@stevea - ironically, without a car fob, I don't need a key chain any more. We have an electronic key pad on our front door, so I don't carry the key. I'm actually very much looking forward to this, unlike the people who are upset at no fob option.

Carl Thompson | February 7, 2018

Also many (most?) car child safety locks automatically disengage in case of accident. So the door can be opened from the inside.

Frank99 | February 7, 2018

Carl -
I don't know how to test that without my insurance company getting pissed with me, but I wonder if you have any backup for that? It's not clear to me how a mechanical child lock is going to get disengaged in an accident.

hokiegir1 | February 7, 2018

I was also wondering if, as someone said earlier, when the doors unlock with air bag deployment, they would be able to be opened from the outside -- so parent/front seat passengers get out with the manual release, then open the back doors to let the passengers out, since the external handles are manual, unlike on the S?

jaroslawbednarz | February 7, 2018

This is the exit procedure in the event of a 12V power loss:

Front passengers exit the car using emergency levers, then they open the rear doors from outside.

gwolnik | February 7, 2018

What if you are alone sitting in the back because you have FSD and then you get in an accident when some other vehicle hits you (because it would never be the fault of your car, of course!) What if you are old and have severe arthritis and can't crawl into the front like a kid (which is why you have FSD, duh!) Now you are trapped in the back on a lonely country road and the jerk that hit you is dead or trapped and can't help you. Then your lithium battery pack starts to smoke. Just like the emergency inside trunk release (presumably for kidnap victims,) there needs to be some type of emergency rear passenger compartment door release, but child proof, of course!

RedPillSucks | February 7, 2018

@gwolnik That's a lot of what-ifs that could easily be speculated about in an ICE car.
If I had a dollar for how many people I see having to open their car door from the outside because they have issues with the handle inside, I'd be a millionaire. Sure, the issue is there but its not as big an issue as people are making it out to be.

Carl Thompson | February 7, 2018

@Frank99

I've read that before and I was able to find this on Google:

https://www.google
.com/patents/US9334681

Carl Thompson | February 7, 2018

@hokiegir1:
"... since the external handles are manual, unlike on the S?"

The external handles are not manual on the Model 3.

Carl Thompson | February 7, 2018

@jaroslawbednarz:
"This is the exit procedure in the event of a 12V power loss:

Front passengers exit the car using emergency levers, then they open the rear doors from outside."

Where did you read that? The rear door handles won't work in the even of a 12V power loss (no external handles will).

Coastal Cruiser. | February 7, 2018

gwolnik "What if you are alone sitting in the back because you have FSD"

I used to have dreams as a kid that I was in the back seat of a car, and the car was driving down the street quite well.
--------------
gwolnik, you should watch a movie called Final Destination

JAD | February 7, 2018

It is better than in a coupes that don't even have back doors. Hasn't been a problem for them, so why should this car be different?

eeb9 | February 7, 2018

I solve this very simply by refusing to carry passengers in the back seat at all. My Model 3 capacity is set to a max of two. Anyone else needs to find a different ride.

;-)

Frank99 | February 7, 2018

Carl -
I'm not sure that helps - it was filed in 2014 and granted in 2016. As a patent, it should be "novel" as of the date of filing, which would indicate that no cars prior to 2014 had a system as described. Perhaps newer cars have this functionality, but I'm not quite sure how you would determine if any particular car did - asking a salesman at the lot would likely get you an answer though the truth of that answer would be difficult to ascertain.

jordanrichard | February 7, 2018

Are we positive that there is no emergency release? On the Model S, the releases are just below the rear seat, behind a slit in the carpeting.

Also with Tesla's emphasis on safety, do you not think that there is a logical reason for them setting the car up the way they did.

Carl Thompson | February 7, 2018

@Frank99

Yeah, I have no idea how to determine how many cars have this sort of system. But I suspect if there is one patented approach there may be others. This particular method is electronic but I would expect there are mechanical methods as well.

Frank99 | February 7, 2018

I'm simply not worried about the rear doors. If my kid is in the back, and is old enough to get themselves out of the car, and is conscious, they'll be over the seats and out the front door faster than I will be. If they're not old enough, or they're unconscious, then whether there's a latch on the inside is immaterial. I suppose gwolnick's arthritis-stricken grandmother might have a problem - but she's unlikely to be able to reach down and access the Model S rear door release either.
Access to the rear seats is much, much better than any two-door coupe, or the third-row seating in just about any minivan or SUV, and I don't hear howls of complaints about how dangerous those are.

Frank99 | February 7, 2018

Carl -
I don't expect much in the way of mechanical methods. Designing something that went into each door, and that could reliably handle front/rear/side collisions along with rollovers, sliding off the road on ice, etc. would be...difficult and expensive. That patent is the most straightforward way of solving the problem.

stevenmaifert | February 7, 2018

Per the Model 3 manual, (and personal observation of my M3) only the front doors have a mechanical door release. Model 3 has rear door child safety locks that disable the electric door release. The obvious solution is to put the kids in the trunk where there is a mechanical release.

MTTPA | February 7, 2018

I'm with JAD. I currently drive a 2D coupe and am not worried about not having a rear door for emergency exit. Not having a manual door release in the 4D M3 is way less of a worry than my kids sitting on a tank full of flammable liquid.

Carl Thompson | February 7, 2018

@stevenmaifert

Yeah... Or if you put them on the roof they'll be thrown clear in case of accident!

Coastal Cruiser. | February 7, 2018

I really like stevenmaifert's suggestion. But given the glass roof, Carl's suggestion would be in keeping with the old adage "Children should be seen and not heard".

Frank99 | February 7, 2018

If you strap them to the nose of the car, you get lots of advantages:
1. Protects the nose of the car in cases of minor accidents
2. Keeps the bugs off the nose of the car
3. If you're ashamed of the nose, they'll hide it (kinda like growing a mustache).
4. Easier to access them than if they're in the rear seat....

JohnJSS | February 7, 2018

Everyone thanks for the replies. It is good know about the 12V battery location and doors unlatching in the event of airbag deployment.

It is not just the kids. I will let adults ride in my car, at least if they stay on there best behavior.

Rutrow | February 7, 2018

@ Frank99, strapping kids to the nose of your Model 3 increases the drag coefficient from 0.23 to 0.38, same as the Bugatti.

ReD eXiLe ms us | February 7, 2018

There is a patent for what Carl Thompson notes, I did not find a regulation that requires it be used...

Automatic door child safety lock release in a crash event
US 9334681 B2

https://www.google
.com/patents/US9334681

"An automated child safety unlocking system for automobiles which disengages the child safety locks and unlocks the doors at appropriate times during events such as vehicle crashes. The vehicle ECU continually monitors the status of the vehicle to check if a crash event has occurred via various methods such as the status of airbag deployment, accelerometers placed in the car, and crumple points. In the event of a crash the vehicle ECU transmits one of at least two CSL command signals a child safety lock ECU. The command signals are each specific to an event severity and event type, and the child safety lock ECU then interprets the signal and acts according to the signal type. If the data interpreted indicates a crash, the child safety lock ECU unlocks the child safety locks, and if it does not determine a crash has not occurred, the locks remain engaged."

That description seems to be in regard to an electric latch system. So, again, it is exactly the same as on an ICE vehicle. This is not an issue at all.

If someone is alone in the rear seat while the car is being autonomously driven, I would hope the child door locks would not be engaged by default. It makes it rather hard to pick up new fares when the first is trapped inside. The presumption is that typically it would be adults, not children, that would be using an automated taxi service. Though perhaps some might send their own car to pick up or drop off their own kids.