Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hopefully i can help..
There is syncronization procedure you can try if you havent done so already :- Turn ignition switch to position 2 / Turn ignition switch to position 0 and remove your key / Within the 1 minute period - press and hold the key lock button , press the unlock button 5 times / remote should now operate system - if not then try going through the procedure again.if it still fails then fault will normally be with the actual key in itself in regards to signalling faults not being picked up etc or received ..... Normally on these cars any new keys or keys to be added or programmed as such have to be done on Diagnostic equipment mercedes specific usually - unless you have good local auto locksmith with desired equipment to do that for you and test the keys are actually working..I do hope this helps