Mercedes S350 W221 doors wont unlock
Thread Starter
Junior Member
Joined: Sep 2019
Posts: 39
Likes: 5
From: Moscow
S-class W221
Mercedes S350 W221 doors wont unlock
Please i really need help, last week my car started a fresh madness, i didnt drive it for like 4 days and when i wanted to go out, the car wont unlock when i press the key fob... i dont have a manual key on the key fob to use open it manually cus i bought this car with one key and there was no manual key on it, so that night i went outside and pressed the unlock botton several times while standing near the car, then i noticed the dashboard light was on.... but UNLOCK light on the exterior didnt flash, so i went closer and found the door was already open, i locked it back and the next day when i was going out, it opened at once but the lights on side mirror and tail-lights didnt flash .... i drove around for hours and returned home. Now, for another 3 days i didnt drive, but when i was going out again yesterday, the car wont unlock, i did what i did the last time but the car doors still wont unlock at all.
MY QUESTION IS which battery do i need to change??? the key batteries??? the auxiliary battery???? the main battery in the hood???? im very lost!!! please can anyone advice?
MY QUESTION IS which battery do i need to change??? the key batteries??? the auxiliary battery???? the main battery in the hood???? im very lost!!! please can anyone advice?
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,141
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
Please i really need help, last week my car started a fresh madness, i didnt drive it for like 4 days and when i wanted to go out, the car wont unlock when i press the key fob... i dont have a manual key on the key fob to use open it manually cus i bought this car with one key and there was no manual key on it, so that night i went outside and pressed the unlock botton several times while standing near the car, then i noticed the dashboard light was on.... but UNLOCK light on the exterior didnt flash, so i went closer and found the door was already open, i locked it back and the next day when i was going out, it opened at once but the lights on side mirror and tail-lights didnt flash .... i drove around for hours and returned home. Now, for another 3 days i didnt drive, but when i was going out again yesterday, the car wont unlock, i did what i did the last time but the car doors still wont unlock at all.
MY QUESTION IS which battery do i need to change??? the key batteries??? the auxiliary battery???? the main battery in the hood???? im very lost!!! please can anyone advice?
MY QUESTION IS which battery do i need to change??? the key batteries??? the auxiliary battery???? the main battery in the hood???? im very lost!!! please can anyone advice?
And then get a new key with the mechanical key in it...
Thread Starter
Junior Member
Joined: Sep 2019
Posts: 39
Likes: 5
From: Moscow
S-class W221
Thread Starter
Junior Member
Joined: Sep 2019
Posts: 39
Likes: 5
From: Moscow
S-class W221
I did exactly just that but it still didnt open, i have resolved the problem anyway, the problem was from the second battery in the boot not the main battery in the hood, i bought a new one and its all working fine now
