Key Fob Reduced Range

[thefast1]

Yesterday both my keys seem to have developed a reduced RF range fault, previously they would lock\unlock the car from a good 10m or so but now you have to be near the front of the car, no more than a metre away for them to work, It's not the batteries as the spare key hardly gets used and is relatively brand new, I read some ware that there is an RF amp that can fail, does anyone know where this located in a 2005 CLK Cab, what it looks like and how I could test it please? if anyone had one replaced what sort of costs, cheers guys.

 

[Motorvating]

The signal is a radio frequency (RF), thus it is prone to external interference.
Because the RF used in central locking is unlicensed as are many other devices that use RF, you often have interference from such things as wireless telephones, wireless CCTV etc. If you are near a telecoms mast you will be in an area with a huge amount of RF often causes problems with many RF devices.
Electrical items breaking down can also cause this problem e.g. a thermostat in a nearby immersion heater or light bulb breaking down.
The way to test if your fob is a problem is to go out of the way from all external interference (country lane) and try your fob out.

 

[kolobos]

Yesterday both my keys seem to have developed a reduced RF range fault, previously they would lock\unlock the car from a good 10m or so but now you have to be near the front of the car, no more than a metre away for them to work, It's not the batteries as the spare key hardly gets used and is relatively brand new, I read some ware that there is an RF amp that can fail, does anyone know where this located in a 2005 CLK Cab, what it looks like and how I could test it please? if anyone had one replaced what sort of costs, cheers guys.

Hi, you say its not the batteries, have you changed them? I had similar issues with a car once where i changed the batteries and they were worse than the original ones! Turns out the batteries weren't powerful enough even though the voltage was correct. I changed them for some Panasonic ones and that did the trick, worked fantastically. Try some proper good quality batteries and take it from there.

Regards,
Steve...

 

[didi w203]

Mines reduced dramatically as the rear windows are tinted. I have to point the remote towards the rear of the car to work. ..does not work from the front. Still. ..it works tho

Sent from my GT-I9300 using MBClub UK

 

[thefast1]

Thanks all, must have been some sort of interferance as it has started to work as it should again, funny thing is we have a plug in wireless RF doorbell near to where the car is parked and that kept just ringing by itself on the same day as the fob was playing up, but all back to normal now.

 

[Motorvating]

Thanks all, must have been some sort of interferance as it has started to work as it should again, funny thing is we have a plug in wireless RF doorbell near to where the car is parked and that kept just ringing by itself on the same day as the fob was playing up, but all back to normal now.

Then it was interference then. Chances are it will come back the next time the offending frequency is used, RF interference tend to have patterns because humans are creatures of habit.
The biggest offenders are wireless CTV cameras and wireless telephones that have been brought in from outside the EU, so you have unlicensed frequencies in or near the same frequency range of your fob.

 

[Motorvating]

Mines reduced dramatically as the rear windows are tinted. I have to point the remote towards the rear of the car to work. ..does not work from the front. Still. ..it works tho

Sent from my GT-I9300 using MBClub UK

Nothing to do with the tinted windows, RF travels through vinyl no problem. I'm no expert on central locking but I would imagine the receiver, or one of the receivers on the central locking has problems.

 

[didi w203]

Nothing to do with the tinted windows, RF travels through vinyl no problem. I'm no expert on central locking but I would imagine the receiver, or one of the receivers on the central locking has problems.

Yes it does. Before rear window was tinted I could unlock/ lock from anywhere around the car from around 7 meters now I have to be very close and remote aimed at the back.
There was a bit somewhere on here about metallic tint and normal tint thus affecting remote locking/unlocking after tinting.

I know this as I tinted the window myself and the range dramatically reduced..removed tint and all was well...re-tinted again and reduced operation of remote. Or maybe receiver faulty??? Na.

Sent from my GT-I9300 using MBClub UK

 

[Motorvating]

Yes it does. Before rear window was tinted I could unlock/ lock from anywhere around the car from around 7 meters now I have to be very close and remote aimed at the back.
There was a bit somewhere on here about metallic tint and normal tint thus affecting remote locking/unlocking after tinting.

I know this as I tinted the window myself and the range dramatically reduced..removed tint and all was well...re-tinted again and reduced operation of remote. Or maybe receiver faulty??? Na.

Sent from my GT-I9300 using MBClub UK

You didn't say you had put metallic tints, so presumed you went for the general vinyl tint. If you used metallic you may have problems with fm reception as well, thats why this type of tint isn't the tint of choice for most people.
Even so, I imagine you haven't put the metallic tint on the front (75% light legislation) so it shouldn't effect the range from the sides of the car if level with the side doors, or did you tint the front doors?

 

[didi w203]

Fm signal works fine. Only tinted rear window and two rear sides. Fronts are not tinted. Everything worked fine til rear window and now low range signal to lock/unlock. . Not bothered at all.

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