2004 C320, M112.946

Vehicle fails to crank, unable to communicate with ME control unit using a scan tool.

Five blocks of wiring connectors are present at the top of the control unit, numbered 1 to 5, front to back. The first block presents with 9 numbered pins connected to a single wiring harness plug connector. Removal of the plug reveals a smokey grey discoloration surrounding pin #5.

Any information as to what circuit is served by this pin?

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