jack1316

Today I received my new key fob with the chrome contour, I switch the internal, everything seems ok, lock, unlock, trunk all working until I try to start the car. The car does not recognize the new key. I switch back the internals on the old black key fob to get the same problem (everything is working but the car does not recognize it anymore). Is there something I can do to get my old black key working?
Any help would be appreciated. It's a 2005 E55.

jack1316

55 readings and nobody has any idea how to solve that problem, a little help from Mercedes E55 owner would be much appreciated.

Strigoi

Look at that! 90 views and still no answers.

Views mean nothing. I'm one and have nothing helpful to say.

bbirdwell

Disassemble, inspect with magnifying glass (or better yet, head loupes) and look for a bad solder joint. Confirm the red led next to the "lock" button illuminates when buttons are pushed. Point the tip of the key fob at your cell phone camera, depress button and see if the infra-red LED is activating. I lean towards a solder joint that cracked.

jack1316

Thank you bbirdwell for your answer.

newe55guy

I dont get on much here. The FOB itself has some coding. I wwent down your road last year and there is NOTHING you can do to swap FOB covers. Sorry to bring bad news

jack1316

I cannot see any solder problem. The red led is also ok. Concerning (Point the tip of the key fob at your cell phone camera, depress button and see if the infra-red LED is activating.) I dont see the infra-red LED.

jack1316

Did you try to put back the electronics in the original key fob? if so did it works?

newe55guy

cost me a new FOB man...

bbirdwell

That IR signal is how the fob and EIS handshake to confirm the key is valid.

jack1316

It looks I will need also a new key fob. With the right knowledge I could avoid this mistake.