Hardware events in the PCIe Expansion Node are detected by the integrated management module (IMM) in the compute node that the expansion node is connected to.
The IMM logs PCIe Expansion Node events in the system-event log in the compute node. In addition, the IMM sends that event to the CMM and to the IBM Flex System Manager management node, if one is installed.
See the documentation that comes with your compute node for information about viewing the event logs.