help identify wire plug under tank

[XLR8R]

had my 2010 S1000RR engine rebuilt by a mechanic who does race bikes but never a bmw. he couldn't identify a plug (where to plug it in). took it to my local dealer and they freaked out because nothing is stock and we don't work on race bikes???? they treated my mechanic like he was a moron (this guy builds for CCS and AMA Pro riders).
when I turn the key, I don't hear the ECU or anything and it wont start.
can someone identify this plug and tell me where it goes? it is the wire with the blue tie wrapped around it

thanks for any help