The Direct Select Address (DSA) may be coded in word 7 of the reference code.
This is either a PCI system bus number or a RIO/HSL/12X loop number, depending on the type of error. With the information obtained here, and the information in either the card position table (for PCI bus numbers) or the information in the loop-number-to-NIC-port table (for RIO/HSL/12X loop numbers), you should be able to isolate a failing PCI bus or RIO/HSL/12X loop. Follow the instructions below to translate the DSA:
lshwres -r io --rsubtype bus
The result will be in the form:
unit_phys_loc=Uxxxx.yyy.zzzzzzz,bus_id=a, ......
Find the bus id "a" entry that matches the decimal bus number you determined in step 2. Using the corresponding Uxxxx value, look up the unit model or enclosure type using the Unit Type and Locations table in Locating FRUs.