W203 Key fob not opening car (Not fob battery)

[blackscooby]

Hi,

I've got a problem with my W203 C32. Both my fobs fail to unlock the car. Changed the batteries in 1 fob and it still doesn't work.

I can open the car with the key (alarm sounds). Once the key is in the ignitiion the alarm stops. Then it's possible to lock and unlock the car with the fob.

However if I leave the car overnight it will fail to open the car again.

Any ideas ?

Thanks

 

[gurmukh]

I am having the same problem, have you had any help or have you resolved the problem

 

[zebmapara]

hi, guys i am having the same problem, any ideas pliz help

 

[Dec]

Any ideas ?

Does the locking problem exist immediately after the car has been driven? Just thinking that maybe the car battery is in poor condition.

Dec

 

[Diesel Benz]

On a 203 I believe the antenna at the car or the antenna connector to the amp is usually the issue.

Can you open door locks if you point the IR receiver at the door handle with your key?

 

[Nibbo]

I had the same and sorry to say it was just dead and I had to buy a new one from MB for about £200.

 

[Diesel Benz]

I had the same and sorry to say it was just dead and I had to buy a new one from MB for about £200.

You had to buy a new MB (quite cheap)? Or a new antenna amplifier, or a new key?

But did both of your keys fail at the same time? Sounds unlikely and I understood both keys stopped working in this case.

 

[Nibbo]

You had to buy a new MB (quite cheap)? Or a new antenna amplifier, or a new key?

But did both of your keys fail at the same time? Sounds unlikely and I understood both keys stopped working in this case.

oooops... good spot DB. I hadn't noticed that both had failed in the first post.

 

[zebmapara]

w203 2006 c180, remote key wont open or lock my doors

let me fully explain the situation guys, its a w203 2006 c180, saloon,before i culd lock/open the doors from miles away, but now i have to stand so close to the drivers door just by that sensor on the door handle and at times they dont lock or open until i have pressed a million times. i have tried my spare key and its just the same. there is a red light on the key that flashes wen i press the key. my boot/trunk wont open as well unless if i use the button on the door. this happens mostly after i have just parked the car. pliz help

 

[Diesel Benz]

let me fully explain the situation guys, its a w203 2006 c180, saloon,before i culd lock/open the doors from miles away, but now i have to stand so close to the drivers door just by that sensor on the door handle and at times they dont lock or open until i have pressed a million times. i have tried my spare key and its just the same. there is a red light on the key that flashes wen i press the key. my boot/trunk wont open as well unless if i use the button on the door. this happens mostly after i have just parked the car. pliz help

Very useful to have detailed info about the car and what is happening with it. But you could also answer specific questions placed earlier like: "
Can you open door locks if you point the IR receiver at the door handle with your key? ".

The point is that it looks like your radio receiver is not working which means you can only lock/unlock the car via the IR connection. IR only works if you point the IR receive with your key close to the car. It does not work even if you are next to the car if you point away from the car. This is why it is important to know if your keys work when you point to the door handle IR receiver from a distance preferably not more than a metre or a few metres (it should work from 10 metres at least if all parts are in good condition and you point directly to the IR receiver with the key).

By the way, it should not work from miles away even through the radio but it should work far further than with IR. I know you did not mean this literally but it is better to try to be very accurate with the description, never know what other forum members want to know and how literally they read the given info.

 

[zebmapara]

just to clarify one or two things, i Can only open door locks by pointing the IR receiver at the door handle with your key. my boot is not opening from the key as well, only from the button inside the driver's door and wen i said before i used to open my doors miles away i only meant i never used to stand too close to the car, thanks MD. i just changed my batteries in my key and nuthing has changed, i guess the problem culd be what a fellow forumist mentioned earlier on, RADIO RECEIVER. now whats next, pliz help

 

[zebmapara]

ok guys i am back with a smile on my face, u wont believe how i solved my problem. just went to my boot were the fuse box is located on the left side of my w203 with the car in front of me. fuse number 8 is the one for remote central locking. for some reason it was half way out and i just pushed it back inside and thats its FM and AM radio reception is back full force and i can remote lock from yards away from the car.

 

[lynall]

Old thread i know, but after wifes central locking packed up i thought here we go!
But one quick google later, loads of talk of dodgy recievers etc, then happened on this thread, and the bit that caught my attention was the mention of poor fm/am reception having noticed that the radio signal was rubbish recently, and the mention of fuse 8 in the rear sam, two minutes later and one blown fuse replaced im a real happy bunny:bannana:

So thank you MB Forum
Lynall

 

[Henke's Mercs]

Hi,

It sounds like the anti tow and alarm control unit.

It's found in the boot on the left hand side next to and connected to the rear SAM. Some trimming will have to be moved to access it.

These units are known to have faulty capacitors.
As the capacitor slowly deteriorate, both range and time between lock and successful unlock will reduce.

Eventually you will not be able to lock or unlock the vehicle other than with the blade key. The alarm will not arm.

 

[SamPcdCar]

We had a similar problem with our SL after someone tried to steel it and we ended up having the EIS (Electronic Ignition Switch) replaced which fixed it. Apparently it basically checks it is a valid key then gives the ok for the message to be passed to the central locking control unit.

 

[Rickman74]

Hi

I have a MB CLC 220 CDI sport. I bought it 7 months ago. The key opened the doors from a distance (5 metres plus away) for the first 2 months. Now I can only open the car by having the key directly in front of the IR sensor on the drivers door. It is intermittent as when it is a lovely hot sunny day, as the car is that shiny it reflects onto the IR sensor and won't open. I am so frustrated. I love the car but this is killing me. I have dropped shopping because i can't get in it. Please please someone help! I keep reading about the FM radio component but MB need to know what part I am talking about. If someone anywhere can help me solve this mystery I will be forever grateful. Thanks in advance.

 

[markmifsud]

Have you tried to replace the batteries that power the key?

you lost me on the FM radio also

 

[Dec]

The radio antenna in the back window picks up the RF signal from the remote fob, the antenna may share a fuse with the car alarm, if the car alarm is faulty it may blow the fuse, fuse possibly in the boot.

What year is the car?

Test the car alarm for 3 minutes, see… http://www.mbclub.co.uk/forums/electronics/169666-w202-how-test-car-alarm.html


Dec

 

[topdogbright]

Old thread i know, but after wifes central locking packed up i thought here we go!
But one quick google later, loads of talk of dodgy recievers etc, then happened on this thread, and the bit that caught my attention was the mention of poor fm/am reception having noticed that the radio signal was rubbish recently, and the mention of fuse 8 in the rear sam, two minutes later and one blown fuse replaced im a real happy bunny:bannana:

So thank you MB Forum
Lynall

I am very grateful for you guidance I replaced fuse 8 which was blown as you recommended on my mecedes 2004 W11 eclass 270 Diesel it cured all of problems that I had, the car can now be locked from a distance with key fob (instead of standing next to drivers door handle receiver) the radio tunes in to all stations the sat nav is working much better, it broacasts direction voice over the traffic warnings and radio broadcasts.
You help saved me a lot of frustration and expense. Thanks again from Topdogbright