Deadlocking Inside

[Momo1]

Since buying my 5th Merc (CLS350d), I have been deadlocked in the car on four occasions, exiting only by crawling into the back of this four door coupe and escaping through back doors, the front doors both deadlocked with me and the key IN the car.
Various Merc garages (not dealerships) tried to locate the problem but could not see any logged error codes, and when I paid £1,000 to have both front door locks changed, the problem was still present. I made a complaint to MB HQ customer services, who noted the issue and I also took the car to MB Basingstoke. Although, not 100% certain, they discovered the alarm siren unit was linked to an error code, not found by other garages with basic diagnostic equipment.
I thought I would mention this, since reading about alarm siren faults on this forum, and of course it being a safety issue.
The last time the fault occurred I had the presence of mind to remove the key from the fob and with window down insert into the lock from outside. That worked but not ideal.

 

[Blobcat]

Hello and welcome,

I don't think your issue has ever come up on the forum before

 

[V6Matty]

new one on me too, i know you can lock the car by the fob while you're inside and it's deadlocked (disabling the interior door handles), so this would make me think that your car is somehow doing that, but only to the front doors if you're able to get out the rear ones.
Have to admit I wouldn't have a clue where to start looking, but hopefully one of the other regular indy's here might have an idea