ML320 2009 - Key Fob Interference

[BobbyK]

I have been having increased issues unlocking/locking my 2010 ML320 using the key fob and wanted to know if anyone has experienced the same alleged interference from the Mercedes Technician's explanation.

Up until yesterday it only happened at home, but yesterday it happened when I was out with my family. The car won't unlock/lock using the key fob button. Technician has come out and explained there are three ways the car can be unlocked:

Using the usual RF/Mhz
Using Infrared, by pointing the key directly at the small receptor on the drivers side door handle
Or by taking the skeleton key out and physically unlocking the car

He explained that RF/Mhz method can sometimes be affected by BT telephone lines in the area or WIFI. has anyone heard this? I have never experienced it with any cars previously.

To open the car I have to use the Infrared method which is getting increasingly annoying

MB Bristol have checked the batteries both sets of keys and they are fine

But if anyone has experienced this I would like to know asap before I go back to the dealer.

[MURRAY007]

that tech who came out to you, is talking bks about the wifi, telephone lines.

yes you can use the blade key to unlock the car, (alarm will go off) but soon as you put key in ignition that will stop.

if the batteries in the fob are fine. (easy way to chk is press the key button and see if the red light blinks on the acutal key fob itself.

most keys are run off the OCP sensor, which is the device by the rear view mirror.

most MB garage should be able to tell you straight away if its the OCP or the Key itself.

[Watchman]

Somewhere in the documentation there should be a certificate or statement of conformity regarding the transmitter. This ought to state what frequency they operate at, which (I'm betting) is not the same as wifi.

I have a 2008 ML320CDI and have never experienced this problem despite my house having 2 wifi routers, wireless phones and my kids playing with MPR radios.

Do you have a spare transmitter? If so, does this behave in the same way? If so, then (process of elimination) the car receiver is most likely to blame. Not going to be a cheap fix though.

[Watchman]

Question: does this happen only at home or everywhere you use it?

Prove the tech wrong by going out into the countryside where there are no sources of interference and try it there. If it still fails to work properly, it's the "kit" (car or transmitter).

[LamboRaj]

Have you had any tint film installed on the rear windows? Some tint films can cause the aerials in the window not to pick up the signal, it can also be a faulty aerial amplifier.

[BobbyK]

Thanks for the suggestions. Basically the car car is cursed. I have had the car since end of Sept last and we have had a huge amount of issues with it, mostly electrical, but also included MB having it for nearly 3 months whilst a door lock was manufactured by the factory (they need to be exactly matched for each chassis). Finally lost my patience with it when the auto close boot stopped working last week. So spoken to Mercedes Bristol who we bought it from and agreed they will find a replacement car. Hopefully they can source one of the last W164 models that had the technical modifications for the last run before the new model was released.