vvrjrlaw

I have recently developed a problem with my keyless go. It's a 2006 cls55 and when I enter the car put my foot on the brake and hit the start button on the shifter it displays "key not recognized". I then lock the car open the door which sets off the alarm. I put the key into the ignition which shuts off the alarm remove the key and then the key is recognized and the car starts. This is not consistent but is happening more and more now. It will also without prior warning display the same "key not recognized" while the car is moving. The display turns red, I insert the key into the ignition and the red display goes out I remove the key and the car is fine. I only have one key for this car and the dealer is 65mi away. Any thoughts? Possible removal of the battery terminal for a soft reset? Or a re sync of the key? I don't want to shoot blindly but this issue is getting old and it's a pain trying to get the key out of your suit pocket once the red light goes off before the car shuts down. I've searched the forum with no luck. Thanks all.

whyask

i have this SAME exact problem .. from i gather its the key itsself. I too only have one key, ive replaced the battery on it now 3 times JUST TO MAKE Sure , and still it does it randomly from time to time .

vvrjrlaw

From my research there is so much that can pose Radio Frequency Interference ( right down to my cell phone) I'm disappointed the MB didn't design a better system. Seems that when I use the key by physically inserting it into the ignition that stops the problem for a while. Seems the system "re learns" the key according to what I've read. Times I wish the car didn't have the option it's such a pain in the a--. But I love the car. ;-)

aussie e55

bump

PAAMGDUDE

The same issue has been driving me crazy for a couple of weeks....replaced the batteries and did the re-set on the fob and no luck. However what I have found is if I keep my keys separated from my cell phone and away from my money clip which is magnetic, the issue goes away and I can lock and unlock the car without any issues......

vvrjrlaw

I'm doing that now but it continues to go "key not recognized" erratically making it necessary to use the key in the ignition. Very disappointing M.B. Shame on you.