Does anyone have an idea what an OBD2 9243 code is?

This is on a 2003 E55 - the SRS light went on, and the OBD2 system is throwing a 9243 "resistance vale in ignition circuit containing component r12/10 is to high". I've been told that its a "hard fault" that wont erase

The mechanic ("European car mechanic", not MB dealership) had no idea what to do....recommends taking it to the dealer.

 

I have the same error code in my 2005 CLK320 cabriolet and it won't erase.
Do you make any progress with this?
Please let me know
Thanks