Can anyone tell me how to program my key fob after replacing the batteries? this is a 2008 350 clk.

 

Doesn't need any programming. You must have another issue. What is it not doing?

 

Take it to dealer if its still not working with new batteries. Its a dealer only fix unless you are willing to take a chance with non dealer EIS service/repair shops.

 

First of all, I assume that the fob won't lock/unlock the car, but the key still works in the ignition? If the key does not operate the ignition, it's not a batteries - the fob battery are not used for the ignition function, only remote locking. So, if remote locking is not working, check that the red LED on the fob illuminates when you press the buttons. If not, make sure the batteries are working and inserted properly.