So lesson learned. Although the online manual discussed in depth diagnostics for the a
bove Transmission Fluid Cooler Coolant Control Valve, its official name, the same circuit is also responsible for the Transmission Fluid Heater Coolant Control Valve. Notice the similarity in names.
The online manual mentions both upon review, but because I was reading online it appeared like a duplicate with the subtle name difference.The culprit was the Heater one, shown in the picture below. Much easier to change than the Cooler one (no pun intended, because it wasn't cool to change out).
Speaking of which, I did change out the Cooler one, which would have entailed emptying the AC system, the coolant, the lower and upper radiator hose, the lower radiator support, and finally the radiator fan shroud. After crawling around and realizing the 2 screws which held the valve in place were attached to the plastic shroud and had no grounding responsibility, I delicately removed the valve cracking the fan shroud and replaced it that way. I am not proud of that, I like to do things non-destructively, but it is what it is. 
Another note: I bought 2 aftermarket Cooler valves on Amazon for $55 each. I figured I would get at least one good one if I bought 2. Remember the dealer wanted $600 plus dollars as a walk in, and I could find some dealers charging as low as $425 online. Outrageous price but......
First valved leaked horribly and the second one wouldn't fire up. Ended up with the original re-installed, cracked shroud and all. I finally broke down and contacted a mechanic recommended by a friend, he asked which of the 2 did you replace? I said there is only 1, he insisted on 2. Once he pointed me in the right direction I located the
Heater one mounted on the battery box (that's right, I didn't stutter). Broke open my probe and read 1.5 ohms and I knew I was on the right track. BTW - I did measure the other one before changing it out. It barely read 15 ohms, but since it was the only one at the time, I figured it was bad because it was on the low end. When will I learn.
an to the deale, $150 later and a couple of clamps off then back on y voila, no more Transmission Fault message and it drives and changes gears just fine.
One valve is responsible for cooling the transmission, the other one is for the internal heater (I believe), but because they share the same fuse (number 34 in the fuse box) and circuitry, if there is a fault there is the possibility the transmission will overheat. So to scare the bejesus out of everyone, they display "Transmision Fault, Service Immediately"
So best diagnostic to rule out which one you ask? grab your Ohm meter, disconnect the plug on the unit to be tested, turn the meter on to read in the -200 range, a good valve should read 15-25 ohms. A bad valve reads outside of this range, in my case 1.5 ohms.
Hope this helps someone with their 2.5 l which is different than the 1.6 and 2.0 motors.
the location of the
Heater one is in the picture below:
View attachment 81298