I purchased a 2003 SL500 recently, and the one SmartKey works perfectly fine. The other key does not. The blade of the nonworking key works in the door lock so I believe this is the actual remove, but when inserting it into the ignition, I cannot unlock it.

I understand that if this key is the valid key (which I believe it is due to the blade working), I undderstand there is a synchronization process? Can anybody fill me in on this? Thanks!

 

I HAVE PROBLEMS WITH MINE ALSO SOMETIMES IT DOES NOT ROLL DOWN THE WINDOWS OR UNLOCK THE DOORS. SOME DEALERS SAY I NEED A NEW KEY AND SOME SAY I NEED A NEW BATTERY I BOUGHT A NEW ONE AND LET GO OF THAT HEADACHE BUT GOT A $300 BILL