C-Class (W202) 1995-2000: C 200 CDI, C 220 CDI, C 270 CDI, C 180, C 200 K,C 230 K, C 220, C230, C 280

KEY FOB issues

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Oct 14, 2011 | 01:22 PM
  #1  
Justinius7's Avatar
Thread Starter
Super Member
 
Joined: Feb 2005
Posts: 806
Likes: 2
From: Edmonds... good bye SD
KEY FOB issues

Hey it has been awhile since I have been on the forums...

I have run into a slight issue. Last night my wife's 98 W202, fob quit working.

I work over an hour and half away from her work, so I grab my FOB, and drive up to rescue her... and when I got there, my FOB does not seem to work either.

We tried the little "emergency" keys to unlock the doors and trunk, but apparently a previous owner changed locks or keys or something, cause neither fit into the hole.

So I tried: holding fob as close to anteanea as possible, nothing happened. (both keys)
I then tried pointing IR to IR on drivers door, nothing happend (both keys)

BUT when i pointed either key to IR on pass door, they both work fine. Both keys start the car. I tried leaving key in ignition for 5 mins with key on to reprogram and nothing changed.

Any suggestions?

I have not driven her car in over a year, but I did notice that the drivers window was not going down... I asked her how long its been broken, she says last time she used it it worked okay, but she has no idea how long ago it has been. not sure if 2 issues may be related. Also, i noticed the radio did come on and had reception, which may remove bad anteanea from the equasion.
Reply
Old Oct 17, 2011 | 03:36 AM
  #2  
rocbtm's Avatar
Junior Member
15 Year Member
 
Joined: Oct 2010
Posts: 42
Likes: 0
'97 C230
to clarify for some: what's fob? keyless entry?

ain't the batteries lol?
Reply
Old Oct 17, 2011 | 10:44 AM
  #3  
LILBENZ230's Avatar
MBWorld Fanatic!
 
Joined: Jul 2008
Posts: 8,384
Likes: 800
2019 G70 6MT & 2022 Ford Maverick XL
He's talking about the SmartKey, which does not have to have batteries in at all to start the car.
Reply
Old Oct 17, 2011 | 01:26 PM
  #4  
zmatt's Avatar
Member
 
Joined: Jul 2010
Posts: 90
Likes: 0
2000 C230K
sounds like your batteries are old. There is a little clip on the track where the emergency key slides in, use the key to push it in and the top should come off. Inside you will find two watch batteries.
Reply
Old Oct 18, 2011 | 08:29 PM
  #5  
Justinius7's Avatar
Thread Starter
Super Member
 
Joined: Feb 2005
Posts: 806
Likes: 2
From: Edmonds... good bye SD
ill change out the batteries... but i do not believe it is a battery issue.

Yesturday my wife out of habit pressed the lock button on the FOB (SMART KEY) and sure enough... It started working again, she tried the unlock and boot... everything seems to work fine on both Smart Keys.

no idea how, no idea why... nothing changed

so.. this will be one of those puzzles, SO now high on hte agenda is to find a door handle with a matching key to install for future emergencies.

does any one have any ideas of what could malfunction and then be normal again? if its something relativly simple or common i would like to fix just for peice of mind.
Reply
Old Oct 19, 2011 | 04:49 PM
  #6  
DirectLA's Avatar
Junior Member
 
Joined: Jun 2006
Posts: 16
Likes: 0
From: Portland, OR
1999 C230 Kompressor
It may be possible that the IR receiver window, the small square located on the door handle, had dust, wax or some other dirt on it. It has also been known that the IR receiver window will not operate if direct sunlight is shining on it, obscuring the IR light. Was the car parked facing strong direct light on this side? Shade with your hand or an object and try again will usually resolve this. I would bet you had one of these two issues since it is now working again.
Reply
Old Oct 28, 2011 | 01:53 PM
  #7  
Justinius7's Avatar
Thread Starter
Super Member
 
Joined: Feb 2005
Posts: 806
Likes: 2
From: Edmonds... good bye SD
Well... the problem that went away after a few days...

HAS RETURNED... 2 weeks to the day, if not the exact same hour. both times at night, after work.

BUT this time it is worse... pointing at the IR sensor on pass door (which at least left us un-stranded). has even failed.

NOW. I can not get into the car with either smart key, nor the IR.

I ended up having the car towed home last night, so at least it was not sitting in a dark parking lot over night.

Tried to get in this morning, and still no luck. I have ruled out the batteries in the smart key, have also ruled out the vacuum locking system, and the atenea in the rear window.

My next try is replacing the brain that operates the alarm/locking system. (once i can get into the car) will keep trying and hope it magically starts to work again, if not... Do I have to break a window OR is there another way to get into the car, like some secret trick?
Reply
Old Oct 29, 2011 | 04:42 AM
  #8  
yamadjs08's Avatar
Junior Member
 
Joined: Jul 2008
Posts: 32
Likes: 0
500hp+ IS300
Check your fuses, both of my FOB's quit working one day, and I knew that it wasn't the batteries. I tried everything, reprogramming the FOB's as per the manual and nothing worked. It ended up being a fuse blown in the main fuse box under the hood on the drivers side. I can't remember which fuse, probably something to do with the central locking system.
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

 Verdad Gallardo
story-1

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-2

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-3

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-4

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-5

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-6

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-7

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-8

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-9

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
Old Nov 2, 2011 | 11:59 AM
  #9  
Justinius7's Avatar
Thread Starter
Super Member
 
Joined: Feb 2005
Posts: 806
Likes: 2
From: Edmonds... good bye SD
Originally Posted by yamadjs08
Check your fuses, both of my FOB's quit working one day, and I knew that it wasn't the batteries. I tried everything, reprogramming the FOB's as per the manual and nothing worked. It ended up being a fuse blown in the main fuse box under the hood on the drivers side. I can't remember which fuse, probably something to do with the central locking system.
So randomly... they both work again...

I have asked my wife to NOT lock the doors under any circumstances... I am going to try to pull the door locks out, and see if I can figure out why the keys do not work. I read on here, that corrossion is a huge problem with them.

Once I get the locks out, does anyone know if a locksmith can work on these? or will this be a dealer item only?
Reply
Old Nov 3, 2011 | 12:09 PM
  #10  
Justinius7's Avatar
Thread Starter
Super Member
 
Joined: Feb 2005
Posts: 806
Likes: 2
From: Edmonds... good bye SD
So i drove the c230 to work this morning, so i could go to a friends house after work and pull the locks out...

and I noticed, that:

1. the drivers window is not working up or down
2. the sun roof... also lost the close function (when you pull the button downwards) I can still get it to close, by going from SLIDE to UP or visa virsa.


SO, question is... WHERE IS THE BRAIN LOCATED THAT CONTROLS THE REMOTE AND WINDOWS?

or what is the module called so i can google? I want to locate it, and look for corrossion and test the power going to/from it.
Reply
Old Nov 4, 2011 | 02:50 PM
  #11  
Justinius7's Avatar
Thread Starter
Super Member
 
Joined: Feb 2005
Posts: 806
Likes: 2
From: Edmonds... good bye SD
another symptom:

NOW the sunroof works, and the drivers window started working fine... BUT the passenger window quit working.

suggestions? anyone????? please help!
Reply
Old Nov 8, 2011 | 07:45 AM
  #12  
99MBSport's Avatar
Member
 
Joined: Sep 2007
Posts: 203
Likes: 1
From: Franklin Mass
1999 C280 Sport
Car seems to be screwing with you .......is it posessed? Seriously try cleaning the Smart key infra red area and the door handle on the left front. I have a 99C20 and the sensors are located (open and close) in the left outside RV mirror as I have my antennea in the rear bumper area.
Reply
Old Nov 8, 2011 | 06:31 PM
  #13  
Justinius7's Avatar
Thread Starter
Super Member
 
Joined: Feb 2005
Posts: 806
Likes: 2
From: Edmonds... good bye SD
Originally Posted by 99MBSport
Car seems to be screwing with you .......is it posessed? Seriously try cleaning the Smart key infra red area and the door handle on the left front. I have a 99C20 and the sensors are located (open and close) in the left outside RV mirror as I have my antennea in the rear bumper area.
HA... i think it is posessed... i have given up...
Reply
Old Nov 16, 2011 | 01:48 PM
  #14  
Justinius7's Avatar
Thread Starter
Super Member
 
Joined: Feb 2005
Posts: 806
Likes: 2
From: Edmonds... good bye SD
okay... i did give up on this... and ended up buying a W203 C240 for the wife...

BUT for now, i need to get this fixed so I can sell. I will use as a commuter till it sells.

So the past week everything has been being fine. Then this morning... i go to adjust the mirrors, and neither mirror will adjust, i try the windows... the 2 front windows do not work, but the rear windows are just fine. oh, and the door locks... still work fine.

SOMEONE PLEASE ADVISE!
Reply
Old Feb 4, 2012 | 12:18 AM
  #15  
MChilders916's Avatar
Newbie
 
Joined: May 2011
Posts: 3
Likes: 0
2002 Mercedes C32 AMG
Hey- hopefully I am not too late with response- sounds like you need to re-sync the FOB's. To do that you need to double click the "Unlock" button - on the second click hold down- once that is done, all the windows, including the sunroof will go down or open- if you happen to let go of the "Unlock" button before all the windows are down that is fine- I usually hold it until all windows are completely down. Once that is done, you need to do the same thing with the "Lock" button and once the windows and sunroof are closed all the way- the synching process is complete- Do the same for both FOB's --- Hope that works out for you-
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 1 votes, 1.00 average.


All times are GMT -4. The time now is 04:08 PM.

story-0
New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

Slideshow: Mercedes-AMG's new electric GT 4-Door Coupe trades combustion for software, synthetic noise, and more than 1,100 horsepower.

By Verdad Gallardo | 2026-05-20 20:08:15


VIEW MORE
story-1
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-2
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-3
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-4
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-5
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-6
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-7
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-8
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-9
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE