Well the way I read FCOM... (my FCTM does not mention a/c height, just what to do in the event of an alert)...
HOTROD is correct
if the A/C is between 2300ft and 1500ft, there will be NO ALERTS/DISPLAYS
bio161
You are Wrong - have a look again at the diagram on FCOM 1.43.60 p4 where it says
WINDSHEAR MODE ACTIVE
NO ALERTS/DISPLAYS
for flight above 1500 ft. "Alerts" are defined on the previous page as warning, caution, or advisory.
Do not confuse PWS with the Reactive Windshear warning provided by the FAC below 1300 ft.