Well, here's a selection of quotes from the AMM (CL) and the FCOM (NG). It looks like the third quote backs up de facto. The FCOM is less clear (as usual). I think Boeing should have done it my way.
GO-AROUND - the DFCS controls airspeed, and the A/T maintains either reduced or full GA N1.
Reduced go-around is engaged by pressing the TO/GA switch one time. A second press of the TO/
GA switch engages maximum go-around. Other modes can be selected after engines have achieved
the selected N1 limit and radio altitude is greater than 100 feet.
(3) Pressing either TO/GA switch once initiates the reduced GA mode, provides REDUCED GA
logic, sets the reduced GA latch, starts the GA timer, and arms reduced GA (maintaining).
(4) The timer (8 seconds) is reset when the N1 error is within 3% of computed N1, the reduced GA
latch is reset when the timer is reset and the GA latch is reset when radio altitude is greater than
100 feet.
(5) The reduced GA (maintaining) latch is set when the GA timer expires. It remains set until the
DFCS requests a mode change or the A/T is disengaged.
(6) Pressing either TO/GA switch a second time initiates maximum GA mode (sets the maximum
GA latch). The maximum GA latch was armed during the first 0.5 seconds of reduced GA. This
latch provides MAXIMUM GA logic and is reset if the GA latch has been reset by the timer and
altitude (greater than 100 feet R/A) and the DFCS requests a mode change (N1 or speed).
Autothrottle Modes
N1 (green) – the autothrottle maintains thrust at the selected N1 limit displayed
on the thrust mode display, including full go-around N1 limit.
GA (green) – the autothrottle maintains thrust at reduced go-around setting.
With the second push of either TO/GA switch after A/T reaches reduced
go-around thrust:
- the A/T advances to the full go-around N1 limit