Success!!
X2 Pin 23 signal now displaying as "True" EOT values under GM.EOILTS.
Should work perfect in stand alone setups.
Related notes so far.
*Trans Temp value reads 350F now. So this might require a DTC or other related table changes.
*Standard OBD-II Engine oil temperature PID 0x5C doesn't report it. Mode 22 Pid looks fine.
*No assigned byte position for EOT values detected in HS GMLAN broadcasts. However, EOT, MAP, and AC Pressure all seem to tie into high priority msg ArbID 0x120 42 5a 62 5a 42 5a 03 11
That needs a little more research, but the hard part's done.
Thanks again Ross.