[eqplayer11]

I looked through the forums and i could not find anyone with a similar problem as mine. the signal from my remote key to the sensors are weak. I replaced the batteries and it did not help at all. The light on my key lights up when i push. The only way i can make the remote work is if i place the key right up to the sensor on the front left door car handle. Some times it will work a foot or two away but not usually. What is really weird is if i try to open the door from the right side of the car it will work from up to 8 ft away. I heard the antenna shares remote key and radio signal and my radio works fine. When i bought the car the dealer told me i just needed to replace the batteries and that didnt help 8(. Im looking for a few ways to try to diagnose this myself without having to pay alot of money to the dealership. Im wondering if its the sensor in the car door handle that is causing this? or could it be a fuse? or a loose wire in the sensor? any help would really be appreciate thank you.

 

[eqplayer11]

Also can anyone send me a fuse box/panel diagram for a 2004 Mercedes C240? my email is [email protected]

 

[pcy]

Here you go...

 

[eqplayer11]

thank you so much

 

[eqplayer11]

half of that is in german. I am looking for the fuses that would be related to the left door handle remote sensor. or any fuse that might be related to my problem at all

 

[pcy]

convenience locking - Fuses 8,9,21,22,32,33
I don't think blown fuse would cause 'weak' signal.

 

[rudeney]

It's probably not the key or fuses. A common failure on the W203 is with the antenna module attached to the top of the rear windshield. Sometimes it is a bad connection between HD module and the antenna in the glass. Other times it's the module itself. Either way, it's not any easy nor inexpensive fix - the best solution is to replace the rear windshield with factory glass that comes with the antenna module attached (about $2K).

 

[haydenks]

Not Uncommon

I have the same problem with my C230 240. Replacing the batteries didn't seem to make any difference.
The "easiest fix" is just to learn to live with it, just get right on top of the sensor in the door handle before pressing the button.

Good Luck!

 

[asc]

I have the same problem with my C230 too. I have to be right up to the sensor for it to work, and even then it's 50/50. There seems to be no easy fix unless you want to spring lots of money to get such a basic feature to work properly.

I have to use my valet key alot, and if it wasnt for that I wouldnt be able to lock/ unlock at all.

Also, Ive looked into getting an aftermarket system from best buy or something, and save a load of cash.

 

[rudeney]

The RCL function uses both RF and IR transmission. It's usually th RF antenna that is failing. If you aim the key at the IR receiver in the door handle, it should work. The range on IR is very short - 10ft max. But at least that savesbyou from having to use the hard key.