Key fob dying

[gina2201]

Well, pushed the button to open my car and "nothing." Couldn't unlock the car! It did eventually open though so off I went on my journey.

Locked it again at other end, then when leaving, couldn't get in for ages. It just would not work. I presume it is the battery.....

So now my car is parked on the road unlocked.... luckliy I live in a quiet village, let's hope it's till there at 5.15am.

 

[pammy]

yup - sounds like it's the battery.

 

[grober]

If its the single button flip key type beware its not the little printed circuit button switch under the operating button. Its soldered to the pcb with 4 legs and one or more eventually break. The remote then works intermittently as it sometimes contacts the board and sometimes not!. It will eventually fail completely at the most inconvenient time. Mine was 11.30pm on a Sunday night 80 miles from home! Replacement is the only answer as the unit is sealed. they are not cheap and only available from MB. Of course it could just be the batteries as PAMMY said so change them as a matter of course first. You should then see the red LED lighting up as described in the handbook.

 

[Rose Chap]

Shouldn't you always be able to lock the car manually with the key?

Even the black plastic electronic 'key' for my CLK has a slide out traditional key for such purposes.

 

[recycled]

Lock the car manually with the key until you sort the problem out

 

[grober]

The problem is that with cars of that vintage -1996 the remote can also activate/de-activate the aftermarket alarm system/ immobiliser. So therefore no remote means car is immobilised. you can get in and out using the key as suggested but the car wont start even if the siren is de-activated. Don't know if this applies to the car in question but that was the reason for my warning.

 

[gina2201]

If its the single button flip key type beware its not the little printed circuit button switch under the operating button. Its soldered to the pcb with 4 legs and one or more eventually break. The remote then works intermittently as it sometimes contacts the board and sometimes not!. It will eventually fail completely at the most inconvenient time. Mine was 11.30pm on a Sunday night 80 miles from home! Replacement is the only answer as the unit is sealed. they are not cheap and only available from MB. Of course it could just be the batteries as PAMMY said so change them as a matter of course first. You should then see the red LED lighting up as described in the handbook.

Hmm, it is the flip out key and has one button to lock/unlock the car and alarm. Someone at work managed to open the key fob thing and there is 2 batteries? The thing was working fine up until yesterday and then zilch, just stopped, althought after a while it did let me in so I thought I had better not press that button!

Just locked the car manually with the key in the passenger door (only 1 lock) and it locks that door but all other door pins stay up and therefore open! Aaaah, will try and get a new battery/s today and see if it is that, lets hope so....

 

[LastMinute]

will try and get a new battery/s today

While you're at it, get a spare set. That way you won't be stuck next time they die. As long as you remember where you put them...

 

[Brian WH]

Just locked the car manually with the key in the passenger door (only 1 lock) and it locks that door but all other door pins stay up and therefore open! Aaaah, will try and get a new battery/s today and see if it is that, lets hope so....

You should be able to manually push all the buttons down to lock all 3 doors, just using the metal key for entry to the drivers door.

 

[MBManInKen]

Hmm, it is the flip out key and has one button to lock/unlock the car and alarm. Someone at work managed to open the key fob thing and there is 2 batteries?

My W140 had that style of key fob. Contains indeed 2 batteries.

Don't you have a central locking switch in the car? You can just press that with the driver's door open, will lock all the doors (IIRC no other door can be open or it will not work). Driver's door can then be locked with the key. At least that is how my W140 worked.

 

[gina2201]

My W140 had that style of key fob. Contains indeed 2 batteries.

Don't you have a central locking switch in the car? You can just press that with the driver's door open, will lock all the doors (IIRC no other door can be open or it will not work). Driver's door can then be locked with the key. At least that is how my W140 worked.

Problem is my drivers door doesn't have the key lock on the outside, has a white square with the red/green thing for the alarm in it, the door lock is on the passenger side, that means I would have to climb out the other side!

Did go to shop for batteries, they put 2 new ones in (same voltage but different size-still fitted though) and it kind of worked and then was a bit "sticky" so didn't buy the batteries, thought I'd take it to Mercedes on Monday, see if it's the circuit board inside or the contacts as someone suggested.....let's hope it's not too expensive!

 

[fuzzer]

you can test the remote to see if there is sufficient power in it.

press and hold the button and if the batteries are ok , it will flash a bunch of times in the infra red section on the top.

If you suspect that the key is on the way out , it would be foolish to leave it even if it does work to a fashon. IT will break and lock you out the car one day

 

[Benzowner]

Where's your spare? Use that untill you get the batteries replaced

 

[grober]

Theres lots more detail in these posts including how to synchronise the alarm key ( dont think you need to that) and test it with a digital camera . DO THAT TEST! http://mbclub.co.uk/forums/showthread.php?t=26218

 

[gina2201]

Where's your spare? Use that untill you get the batteries replaced

No spare key, second hand car....! Was intending to get one though.

 

[gina2201]

IT will break and lock you out the car one day

Yeah like last night! Managed to eventually get in though after a few minutes of button pressing, I won't lock it now with the button, it is blocked in on my drive way so it isn't going anywhere!

EDIT: I will try and get some more batteries but the correct size tomorrow and give that a go, can't do any harm.....?! I wasn't too sure about the batteries today that were thicker, they may well have been fine but made it harder to shut the cover back on so I want the right size. Oh, and the shop tested the 2 original batteries, one is flat, the other ok, but even with the good one and one new one, it still didn't want to play!

 

[pammy]

Gina

you need to take the extinct batteries with you so that you can get the correct ones. It's not just about physical size but the power they put out.

 

[gina2201]

Gina

you need to take the extinct batteries with you so that you can get the correct ones. It's not just about physical size but the power they put out.

Yeah I'll take them with me, I didn't want to buy the larger size but same voltage batteries as they didn't seem to fit so well and I'm not 100% sure it is purely the batteries that are at fault.
Will find out more tomorrow hopefully!

 

[Howard]

While you're at it, get a spare set. That way you won't be stuck next time they die. As long as you remember where you put them...

Keep them in the glovebox, that way you know they're safe

 

[LastMinute]

Keep them in the glovebox, that way you know they're safe

As long as you can unlock the car to get at them...