Loop start trunks:
3500>00>00 trunk route 00 = DDD
3509>00>15 incoming signal = loop
3520>00>15 outgoing signal = loop
200>9>100 dial 9 for trunk route 00
3018>000>0 allow direct trunk appearance
3000>000>00 place trunk 000 in route 00
9000>200,01>D000 place trunk 000 on button 1 of extension 200
If this does not work, then test your trunks at the DMARC ahead of the system. It's possible they can be ground start.
OR, set up another trunk route, start at route 15 since that one should be all default. Substitute route 00 settings for route 15.