To avoid confusion, first, with A/T LIM the EECs are still in normal mode (not EEC ALT). Not sure if you meant that or not. Anyway...
Just below the section you quoted you will find:
N1 SET Outer Knob
AUTO –
• both reference N1 bugs set by FMC based on N1 limit page and takeoff reference page
• displays reference N1 bugs at active N1 limit for A/T.
The EEC output goes through a "filter" in the FMC, before being displayed. The FMC knows what the phase of flight is, which all have different thrust limits (selectable on the N1 page in the FMC). E.g. if you are in cruise, the N1 Reference bugs automatically change to CRZ limit. If the FMC is inoperable, obviously, these limits will not be shown as the EEC doesn't know which phase of flight you are in and probably doesn't have the tables available either.
Check the FMC fail checklist. You have to set the N1 bugs manually according to the tables in the Performance inflight section.
What degraded limit
is shown, I would be curious to know as well. I did have FMC fail during cruise once, in Classic, and as far as I recall the bugs stayed at the CRZ limit until manually set to G/A limit for the approach, but not sure anymore.
I guess we are moving beyond layman's terms again now.
