Have you tried looking at remote through a digital camera?,you can see if it is transmitting.
Also put the key in the ignition in number 2 position for about 15 seconds, and re-try.
That is the limit of my knowledge, hope this helps.
i want to thank to the members who reply to my thread c250 wont start thanks to you and the info in this forum i repaired my key myself after 2 autosparks told me i needed a new key (£184.00)and cant be repaired my car works fine now THANK YOU VERY MUCH
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