Thanks a bunch SC Tom, Jeff and Ed,
---I checked for diagnostic codes via local Auto Zone, there were none.
---The greater than 60 miles at >60 MPH period (before red triangle panel lamp and engine shutoff) nearly ruled out fuel filter or fuel pump wiring.
Following good lead from Ed (below), I further researched and found this link;
As this article (and Ford procedure mentioned), I noticed intermittent behavior when I tapped the Motor Electronics Cooling System (MECS) pump, which are known to fail after 50K miles.
[ Shame on Ford for including such a poor quality Bosch pump that leads to such a dangerous, repeated, nightmare shutdown at high highway speeds, with no precise indication that the MECS system was at high temperature!!! ] Note: this is not a Hybrid Battery Assembly related part so apparently not covered in warranty.
My local Ford dealer matched exactly the Web discount Ford parts supplier price mentioned in the link above.
I successfully replaced this small MECS pump which is easy to get to (behind at bottom center of radiator) and used new quality Antifreeze/distilled water mix for coolant refill.
Yesterday, I did a greater than 60 miles at >60 MPH highway speed test and no engine shutdown resulted.
This apparently was the correct fix, but I will report back if there are any more related issues.
Thanks again for your great assistance.
Ford Escape-Hybrid 2.3 liter (with 82,000 miles) has run <BR>> well in
usually short trips of <70 miles, but over the last year, only <BR>>
after ~70 miles at >60MPH Highway travel, the gas engine shuts down
<BR>> repeatedly and 2 indicators appear;<BR>> 1) a red triangle, idiot
lamp, with exclamation point in center (General <BR>> Warning red lamp)
appears at upper right of console and<BR>> 2) STOP SAFELY NOW appeared
in text readout window<BR>> <BR>> Other Details from recent 150 mile I95
Highway trip in Maine;<BR>> --For the first 70 miles at ~65 MPH there were no
problems.<BR>> --After 70 miles the gas engine shut down continued to occur
over 20 <BR>> times!!! till I nursed it to my destination at 150 miles
total.<BR>> --External air temp. was 27 deg.F and overheat lamp did not come
on (lamp <BR>> was checked at start check and was working and there was no
sign of <BR>> overheating at either the engine or electronics cooling--clear
plastic <BR>> reservoirs)<BR>> --Battery-Electric Motor continued to work
as normal at low speed without <BR>> gas engine, so problem is apparently
part of gas engine or drivetrain <BR>> process.<BR>> --Each time gas
engine stopped, I had to pull to shoulder (>20 times many <BR>> under
dangerous traffic conditions) key was turned off, removed, then <BR>>
re-inserted and engine started within seconds, like normal --- with NO <BR>>
message or indicator lamps appearing!<BR>> --On return 150 mile trip (at 40
deg. F external air), same thing after ~70 <BR>> miles, the gas engine
continually turned off ~10 times. --- For the last 50 <BR>> miles I
tried an experiment using speed control at 50MPH and that <BR>> worked!! ---
no more gas engine shut downs for remainder of trip. Note, <BR>>
just before, I tried using speed control at 60 MPH but that again triggered
<BR>> the repeated, gas engine shutdown. Ice/drygas fuel blockage issue
was <BR>> suspected but this higher temp. return trip rules that out.<BR>>
--The drivers side radiator electric cooling fan remained on even though gas
<BR>> engine had earlier shut off, and even after switch positioned off and
turned <BR>> back on without start.<BR>> <BR>> Any help in diagnosing
exactly what causes this very aggravating condition, <BR>> which prevents any
highway travel over 50 MPH is much appreciated. <BR>>