Oddly enough, after pulling off the cover, looking at the diagram, CPU2 is on the left and RAM slot 3 is the 1st slot on the left of the board. So, in order for the ILO to function, you need viable RAM in the 1st slot on the board. In this device, that's CPU2 slot 3.
The error in ILO was -- Uncorrectable Machine Check Exception (Processor 2 APIC ID .....
Then -- DIMM Failure - Uncorrectable Memory Error (Processor 2, DIMM 3)
Further in the logs -- Uncorrectable Memory Error Threshold Exceeded (Processor 2, DIMM 3). The DIMM is mapped out and is currently not available.
Finally after I pulled the plugs out of the power supplies, and a hard reset -- The installed number of DIMMs on one or more processors results in an unbalanced memory configuration across memory controllers. This may result in non-optimal memory performance.
The server was completely unresponsive. I've never had the ILO go down like this. Fortunately, this was onsite here. It did come back up and ran normally until maintenance showed up with a new stick of RAM. Also, there's two different types of RAM for these units. You need to grab the part number to get the correct replacement.
Like Scott said, ILO was separate from the system -- apparently in the past, this was true. No longer.