Sluggish Key Fob

One or two (can't recall) common (drugstore etc. retail) coin like battery inside. Pry fob apart.

Yes. If you take out your metal key... you will see a grey button in the slot that can be depressed by that key and allow you to pull the fob apart.

Isn't there a guide in the owner's manual for this? Anyway, if the key now only works close to the car, the issue could be the radio receiver at the car instead of the key (always good to check the key batteries though).

The key (on modern MBs at least) works on both IR and RF. If the RF dies, you need to point to the IR receivers at the door to open the doors. But you do need key battery power for this too. Not sure if IR works at lower battery levels than RF, in that case it could still be the battery in the key. By the way, is it the same with the other key?

I am having the same problem with my 2001 C240. It was not diagnosed until the warrantee expired. It is a radio frequency amp in the roof near the back window. I had so many mechanics look at me like I was crazy because I said the remote and the radio reception were weak at the same time. Of course every time this was mentioned the Basics 101 question was asked, "Did you check the batteries in the fob?". Yes! "Maybe it?s a fuse." I checked all that before I took it for service but they did not believe me. :roll

"C240RedGirl" wrote