# Auto-Locking Doors and Post Crash Safety Features



## bimNaround (Jun 19, 2003)

Assuming first that occupants are properly safety belted in a car, are the occupants of the car in a crash safer with the door locked, not locked or doesn't it matter? I could see where an unbelted person might realize some additional safety by having the door locked because there could be less chance of being ejected from the car if the occupant was unbelted and the door opens up during a crash. Is there any data showing which condition is safer for belted occupants? You eliminate some liability of automatic locking doors (for instance, if someone was trying to get you out of the car without any rescue equipment and the doors were locked they wouldn't be able to help you) by having the doors automatically unlock in a crash. What has everyone chosen for the automatic locking car memory feature (ON or OFF) and why?

On a similar note, I understand that during an accident that the doors automatically unlock, the interior and/or exterior lights come on, the hazards lights turn on, and the battery is disconnected for safety. Is this correct for a 3er? If so, does anyone know the sequence? How can all the lights, power door locks, and BMW Assist work in the case where the battery has disconnected and the engine has stopped? Is there a supplemental (non main battery) energy source for these post crash critical systems?


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## AF (Dec 21, 2001)

Yes the E46 does what you described . . . pretty cool isn't it :thumbup:


I have my auto lock doors on for the simple reason I feel safer driving around with the doors locked . . . this way no one can jump in my car . . .

Come to think of it, I've been driving for 18 years and not one person has ever attempted to even open my door unless it was an invited passenger getting in/out so I guess the whole thing is paranoia :eeps:


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## Dirtboy (Apr 19, 2002)

bimNaround said:


> How can all the lights, power door locks, and BMW Assist work in the case where the battery has disconnected and the engine has stopped? Is there a supplemental (non main battery) energy source for these post crash critical systems?


the only thing that is disconnected is the power cable to the starter. there is still a connection to the battery to run all those things. oh, i have my auto-lock enabled.... cause i'm paranoid  lol :rofl:


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## Kaz (Dec 21, 2001)

Auto-locking=off. My parents' cars have had it and I've always hated it.

If you look at the battery terminal, there is a 2nd, smaller cable coming off the battery. The BST (Battery Safety Terminal) doesn't disconnect this one.


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## LeucX3 (Dec 26, 2001)

bimNaround said:


> On a similar note, I understand that during an accident that the doors automatically unlock, the interior and/or exterior lights come on, the hazards lights turn on, and the battery is disconnected for safety. Is this correct for a 3er? If so, does anyone know the sequence? How can all the lights, power door locks, and BMW Assist work in the case where the battery has disconnected and the engine has stopped? Is there a supplemental (non main battery) energy source for these post crash critical systems?


Unfortunately, i've had the opportunity to utilize these functions on my previous BMW (may he RIP). I don't know the sequence of events, but it happens very quick. By the time my car had stopped after the force of the other car hitting it, everything had already happened.

I could be wrong, but i also think i heard about the fuel valve getting shut off so there's minimal chance of fuel leakage. Everyone who saw the car afterwards were shocked that i got out of it without any injury. BMW safety is second to none (not even Volvo).


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## Desertnate (Mar 11, 2002)

Leuc330Ci said:


> I could be wrong, but i also think i heard about the fuel valve getting shut off so there's minimal chance of fuel leakage. Everyone who saw the car afterwards were shocked that i got out of it without any injury. BMW safety is second to none (not even Volvo).


I have heard this too...back in the cobwebs of my memory. Would make sence if you are shutting off the power, might as well cut the fuel as well.


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## Spectre (Aug 1, 2002)

From my days as an EMT (about 13 years ago), the extrication instructors said that it was safer to have the doors locked. That gave a bit of extra help to the doors in keeping them from popping open. Closed, the doors provided structural integrity, some of which would be lost if the doors opened. I think that's one of the reasons that BMW builds in the latching side impact beams in the cars -- to keep the sides locked down in a collision.


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## bimNaround (Jun 19, 2003)

Thanks to everyone who responded. Those people that have auto locking enabled, do your doors auto UNlock when the car stops or engine is turned off? If so, was this also an option or is the unlocking action dictated by the auto locking setting. I didn't see any mention about auto unlocking in bmwnation car key cfg .


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## AF (Dec 21, 2001)

The doors *don't* unlock automotically


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## yamato (Feb 11, 2003)

i dont have the auto locking feature turn on, but i like to turn it on.

in my opinion, the door lock feature is not accident related. It is more like going into a washroom and you lock the door behind you. This is for preventing intruders from coming in. It happens a lot in Detroit. One story I heard was a guy stopped in a redlight and he was pulled out and the car was stolen. Another story my parents experienced was when they parked to read maps, a stranger opened up the passenger side door and took my mom's purse. I will never drive without the doors locked.


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## ChadS (Jan 4, 2002)

AF330i said:


> The doors *don't* unlock automotically


From bmwusa.com . . . _Crash sensor that automatically turns on hazard lights and interior lights, and *unlocks doors*_


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## bimNaround (Jun 19, 2003)

ChadS said:


> From bmwusa.com . . . _Crash sensor that automatically turns on hazard lights and interior lights, and *unlocks doors*_


AF330i was responding to the question of auto unlocking of the door after stopping and/or shutting off the engine, not in a crash. Thanks for the response.


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