OK Everyone, I give up. I purchased a nice 2005 MCS. The dealer only had one key to give me at the time of the sale, but 3 weeks later he called, and wanted me to stop by, he found another key. The original key worked perfectly, locked, unlocked, everything. The newly found key works in the ignition, but no remote functions.

The 1st thing I did was to drive around with the key that did not work, possibly trying to charge the battery. Then I followed the procedures found on the threads, on how to program the remotes. Turn key to 1st position, take out key, hold lock button, press unlock button 3 times within a 5 second time limit. I even followed another thread that had the sequence reversed as far as pressing buttons. Now both keys don't work. What did I do? Any new procedures? I would really appreciate any suggestions.

 

Naples. The original key that works and now does not. Relearn in the same sequence as you were going to do with the 2nd key. put in ignition cycle key all the way on all lights then off,then hold down lock and press unlock 3 x's. Should work. As for the 2nd key. Since had not been used for so long.
Go back to the dealer. get a knew key. If your under 50K. It will be covered
under fact warranty. Not unless you see damage to the key itself or it looked like it was liquid saturated @ 1 time.\

 

Just tried the original with no positive results. I am holding down the lock on the key, not the console. I must have done a de,de,de, and lost the programming. Thanks for the help

 

Also... when you are programming these keys. When you get one to work properly, you have to push the buttons on the second key imediately following the first key WITHOUT putting the second key in the ignition.