737-6/7 - GPWS - Only when established on approach/Terrain Mesh S...

Friends and fellow lovers of all things PMDG - I had a bit of a hunt through the manuals on 737-6/7 (Note - I do NOT have 8/9), and couldn't find much in terms of GPWS (Ground Proximity Warning Systems).Sure, sometimes when I fly a little misconfigured while established on either a VOR/DME or ILS I get a DON'T SINK (particularly when I do a Go Around).In attempting to replicate an incident which occurred here in Oztraya, a link included below, I was wondering if the GPWS might act *like* an EGPWS if terrain mesh scenery is installed?Any pointers on how the GPWS is enabled for the 737-6/7, and if there is any difference in the 8/9, would be warmly appreciated.Link: http://www.atsb.gov.au/aviation/occurs/occ...tail.cfm?ID=659Yours, Chardy