Locked in car without a key, cannot open doors or windows, is this fault or bad design?

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For what it's worth. Interior boot release handles have been mandatory in major markets for two decades.

But, boot areas can't always be accessed from the passenger compartment in saloons or coupes.

(It was a kidnap / bad guys thing).
I think this is a USA thing
 
What you are describing is the deadlock feature. It prevents someone smashing a window and opening the door - ie makes theft harder. And yes, most UK cars do it.
 
On the majority of the vehicles I've encountered so equipped, you have to push the lock button twice within a certain number of seconds (the theory being that then you can choose what locking you want).

Assuming the B-class is the same, it sounds like whoever locked you in may well have just mashed the lock button repeatedly.
 
As mentioned by others, this is definitely by design. It’s much less likely that someone will get locked in than the car will be stolen by braking the glass and unlocking from the insider.

The solution to being locked inside the car and unable to get out - because the driver walked away with the key, or the electronics fail - is to brake the glass. If you’re concerned, buy a life hammer and keep it in the car.

They’re designed to enable egress when you can’t open the door in emergency situations of all sorts - such as underwater, door damage by impact, etc - and are perfect for smashing glass.
 
Its a UK spec thing (according to my new manual). actually states "For United Kingdom Market only".

At least we dont have glow in the dark boot releases should any Mafia kidnap us and throw us in a boot.
 
But did you try this when the car was locked from outside using the fob?
Both the 211 and 639 will allow the occupant to escape if locked from the outside.
Mind neither are Keyless Gone, so the system wouldn't know if the fob was in, out, or on the moon.

Tbh I'm happy that my mo mo's are of such low intelligence.
 
On the majority of the vehicles I've encountered so equipped, you have to push the lock button twice within a certain number of seconds (the theory being that then you can choose what locking you want).

Assuming the B-class is the same, it sounds like whoever locked you in may well have just mashed the lock button repeatedly.
Not come across any that do it like that since Ford's from the 90s. The 212 does it with a single press as did my 2005 S40.
 
My Lexus models all double lock if the lock button (or touch patch on the door handle) is touched twice within a couple of seconds.
 
Not come across any that do it like that since Ford's from the 90s. The 212 does it with a single press as did my 2005 S40.
Ford have always done this and still do, also encountered on Vauxhall, Honda, Fiat and an older Seat from memory. Used a couple of VW vans that were the other way round (double press disabled deadlock).
 
From my manual:

WARNING

Only for the United Kingdom: if the vehicle has been locked with the key or with KEYLESS-GO, the double lock function is activated as standard. It is then not possible to open the doors from inside the vehicle.

Therefore, do not leave any people behind in the vehicle, particularly children, elderly people or people requiring special assistance. As a result, they may not be able to free themselves in the event of an emergency. They could be seriously or even fatally injured by prolonged exposure to extremely high or low temperatures, for example. In this case, rescuing people from outside the vehicle is difficult.

Deactivate the interior motion sensor before you lock the vehicle. The doors can then be opened from the inside after the vehicle has been locked from the outside.
 
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My Lexus models all double lock if the lock button (or touch patch on the door handle) is touched twice within a couple of seconds.
Wife and daughters Nissans both do this also, definately not just a Mercedes thing.
 
From my manual:

WARNING

Only for the United Kingdom: if the vehicle has been locked with the key or with KEY- LESS-GO, the double lock function is activa- ted as standard. It is then not possible to open the doors from inside the vehicle.

Therefore, do not leave any people behind in the vehicle, particularly children, elderly peo- ple or people requiring special assistance. As a result, they may not be able to free them- selves in the event of an emergency. They could be seriously or even fatally injured by prolonged exposure to extremely high or low temperatures, for example. In this case, res- cuing people from outside the vehicle is diffi- cult.

Deactivate the interior motion sensor before you lock the vehicle. The doors can then be opened from the inside after the vehicle has been locked from the outside.


This clearly demonstrates that MB recognised the safety issue of deadlocks, which is why for many years they didn't follow the herd and fit them even in the UK. It was a known feature of MB cars that they didn't have deadlocks and this was often commented on in reviews stating MB's safety stance. For whatever reason they did eventually join the herd and fit them in the UK. I don't known when the change was made but it's relatively recently because my 2009 W204 can be opened at any time from the inside even when locked with the key. The owners manual confirms that this is the case.

So for a long time MB stood alone on this safety issue and it sounds like they still do outside of the UK.
 
This clearly demonstrates that MB recognised the safety issue of deadlocks, which is why for many years they didn't follow the herd and fit them even in the UK. It was a known feature of MB cars that they didn't have deadlocks and this was often commented on in reviews stating MB's safety stance. For whatever reason they did eventually join the herd and fit them in the UK. I don't known when the change was made but it's relatively recently because my 2009 W204 can be opened at any time from the inside even when locked with the key. The owners manual confirms that this is the case.

So for a long time MB stood alone on this safety issue and it sounds like they still do outside of the UK.
Not sure about this, the original deadlocks that Mercedes refused to fit, were they not a secondary bolt that locked the door so if you smashed a window and reached in the doors would still not open?
Door locks are now electronic and dont use the old mechanical deadlock system anymore. In fact, is it not the case that the doors are automatically unlocked if the car is involved in an accident?
 

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