Unlocking Issues E350 W212
Thread Starter
Junior Member
Joined: Oct 2017
Posts: 42
Likes: 2
From: Columbus, OH
e350 2012
Unlocking Issues E350 W212
Hello,
I have a 2012 e350 sedan, and am having issues with unlocking the car. The unlock button on the key fob (I have only one, and it's not a keyless go remote) failed to unlock the car. This started happening all of a sudden today, but I was able to get it to unlock once or twice after noticing it stopped working. The trunk and lock buttons work, and I have changed the key fob battery today to see of this resolves anything. When the unlock button on the fob won't work, I use the key to manually unlock the car, and when I get the door to open, the unlock buttons from inside the car on the driver and passenger doors are also having trouble unlocking. So I would say the key fob is having the most trouble opening the car, then come the buttons on the door. I have no problem starting the car.
What should I investigate? Car battery, fuse in the trunk, lock actuator, etc...?
Edit: car not unlocking at all from remote. The red light turns on only after pressing the trunk or lock button and the car taking action.
Thanks
I have a 2012 e350 sedan, and am having issues with unlocking the car. The unlock button on the key fob (I have only one, and it's not a keyless go remote) failed to unlock the car. This started happening all of a sudden today, but I was able to get it to unlock once or twice after noticing it stopped working. The trunk and lock buttons work, and I have changed the key fob battery today to see of this resolves anything. When the unlock button on the fob won't work, I use the key to manually unlock the car, and when I get the door to open, the unlock buttons from inside the car on the driver and passenger doors are also having trouble unlocking. So I would say the key fob is having the most trouble opening the car, then come the buttons on the door. I have no problem starting the car.
What should I investigate? Car battery, fuse in the trunk, lock actuator, etc...?
Edit: car not unlocking at all from remote. The red light turns on only after pressing the trunk or lock button and the car taking action.
Thanks
Last edited by Anthony199; Apr 3, 2019 at 03:54 PM.
Out Of Control!!
Joined: Jul 2003
Posts: 15,901
Likes: 4,630
From: North Scottsdale, AZ
'71 Pinto
Definitive diagnose, need to pull fault codes using MB diagnostics. DIY try replacing antenna amplifier (part # 2128201789) located in left c-pillar. You can start shopping here: https://www.ebay.com/itm/MERCEDES-E3...-/131997966192
Thread Starter
Junior Member
Joined: Oct 2017
Posts: 42
Likes: 2
From: Columbus, OH
e350 2012
Definitive diagnose, need to pull fault codes using MB diagnostics. DIY try replacing antenna amplifier (part # 2128201789) located in left c-pillar. You can start shopping here: https://www.ebay.com/itm/MERCEDES-E3...-/131997966192
Out Of Control!!
Joined: Jul 2003
Posts: 15,901
Likes: 4,630
From: North Scottsdale, AZ
'71 Pinto
Door unlocking is based on radio frequency, antenna amplifier receives RF from key to unlock doors - first DIY step to resolve. Not comfortable chasing problem and not under any warranty, have independent with MB DAS check it.
Thread Starter
Junior Member
Joined: Oct 2017
Posts: 42
Likes: 2
From: Columbus, OH
e350 2012
This antenna, you mentioned it's in the driver side c-pillar. Do I need special tools or can I just remove the liner and replace it? For some reason, I thought it'd be under the antenna fin on the roof.
Trending Topics
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Junior Member
Joined: Oct 2017
Posts: 42
Likes: 2
From: Columbus, OH
e350 2012
Newbie
Joined: Jun 2021
Posts: 3
Likes: 0
w212 e300
Thanks for info
so i decide following this youtube.
- i only can lock/unlock with Fob beside of driver's door keyless entry button. (have 2 original keys. all new batteries) (only 1feet distance)
- 1ft distance, all remote fob functionsare ok.
ill update here after.
MBWorld Fanatic!
Joined: Dec 2020
Posts: 2,412
Likes: 1,482
From: 122W, 37N
2016 E350 4Matic wagon, 2019 Ford Expedition, 2019 Chevy Bolt EV
um, there's no IR sensors, at least not on the US model 212's. I believe they use both high frequency and low power low frequency RF, one to detect the key is inside/outside the car, and the other for the actual command and control signals. mine has the option where if the keyfob is on your person, you just touch the inside of the door handle to unlock, and when you get out of the car, you just touch the outside to lock, so you don't even 'use' the fob, it just has to be present.
Newbie
Joined: Jun 2021
Posts: 3
Likes: 0
w212 e300
.
um, there's no IR sensors, at least not on the US model 212's. I believe they use both high frequency and low power low frequency RF, one to detect the key is inside/outside the car, and the other for the actual command and control signals. mine has the option where if the keyfob is on your person, you just touch the inside of the door handle to unlock, and when you get out of the car, you just touch the outside to lock, so you don't even 'use' the fob, it just has to be present.
my w212 e300 is philippines model. and fob was working well. but there is problem after some wiring problems.. . . . i need to do what i can do before spending a lot more. i already spent about 3000usd for 2monthes😂🥲
