My smart key will only unlock all door locks from an area next to the passenger door on the exterior of the car. If tried from other locations around the car the light on the remote flashes and nothing happens to the car as far as unlocking or lights flashing.I have changed the batteries and no change I have also tried to reprogram the key by pressing the lock and unlock on the Smart Key. According to the manual the smart Key should have an extended range. Any suggestions what to do?

 

Have you tried going from global to selective? hold both buttons down for 5 seconds and that will cycle between the 2. You could also have a problem with central locking. The locking uses both an IR and RF signal. RF ia located in the over head control panel and the IR is located in the door handles.

How many keys do you have? Have you tried another key?

 

I tried your suggestion and switched from global to selective and this feature worked but the Smart key still only works inches awayfrom the exterior of thepassenger door. I have 2 Smart keys and both are acting the same. I tried to operate the remotes close to the control panelbehind the rear view mirror and close to the drivers door and nothing happens. Any other suggestions would be appreciated.

 

Did you ever get the range extended? I have the same issue, and would like to increase the range. My remote works well and is brand new, but sometimes it only works best when I am closer.

 

The problem has finally been repaired by my Mercedes Benz dealer. They discovered that one of 2 infarred sensors was faulty. There is one in sensoreach front door. As well the antenae that is located in the rear window was defective as well as an amplifier for the unit was faulty. The antenae and amplifier is used for the radio frequency part of the remote door locking system. Apparently there are two locking systems for the C230's. One is the infarred system from the key fob that only works from line of site to the sensors in the two front door sensors. This system will also open and close the windows and sun roof. The second system isa radio frequency transmitter that transmits to the antenae in the rear window and an amplifier. I'm not sure where the amplifier is located in the vehicle. The repair costswith parts and laborto get the remote fobsworking again was $1500.00 Can.

 

it will be cos to change the anteena u ve got remove or drop roof lining,which is located on the above rear screen,this is on all the 203 models

 

good post! i'm experiencing the exact same problem... my IR works 100% or the time from passenger side, ~50% of the time on the driver side. the RF hasn't worked since i bought the car... not looking forward to the repair bill...

does the stereo's radio receiver use the same antenna/ signal amplifier as the door locks? if so, that'd explain the poor radio reception as well...

 

I think thereare a few things going on here!
First, if the doors were locking and unlocking from a few inches away from the door handles, the infrared receivers were working and therefore should not have been replaced!!!!!!
Second, there is no infrared receiver in the overhead control panel on that model. The models that do have the infrared receiver in the overhead/mirror are much older vehicles.

I think what we have here is a case where the technician at the dealership wanted to get paid for a wide range of repairs. When the remote keys do not work from a distance, any dealership mechanic would know to replace the window antenna amplifier which is attached to the back glass.

The failure of the rear antenna amplifier will affect the radio reception. To test, turn the radio on and push up on the headliner at the point where the rear glass meets the liner. If you hear a difference in reception, there you go!

 

My radio and key just did the same thing (2002 c230 komp) and the dealer said i needed to replace the back window at a cost of $2200. FT. Anyone know of a low cost way to fix this? Maybe a new radio and antenna from a radio shop?

My key does not open the car doors from any angle. The radio does not pick up any stations any more except the ones broadcasting close by.

If you have found a solution, please forward it. Thanks