I knOw how much every one of us hates these loose ending threads with no update on solution. So here goes:
After replacing ALL potentiometers/sensors and solenoids, the problem persisted.
I have been driving like this for a while - nearly got used to it, and beginning to accept this as a fact. I did not want to spend a fortune on a new or used actuator which was the prevailing suggestion from Indys I talked to including my own trusted.
So this week I took her for a routine service (also replaced standard filter to K&N btw and she feels real nice now) and my Indy agreed to have a look at the pinch bolt which was a route I was thinking might have effect. I got a related error on testing it with FES and he said he would look at it just so I would stop nagging him about it.
Lowered the box and looked at the bolt. It was tight like hell so I agreed this must not be the cause. Note that he has released the long vertical pin that crosses the pinch bolt and then reinserted it (don't know the name of this part).
After oil and service, she was cleaned from the bottom using steaming water jet. This led to a fault in not being able to engage reverse (clunking twice and giving up)Pressurized air and contact cleaner did not cure this so we did an EOL.
Magic - the sele now selects and engages without a problem!!!
And this is fine for the last 3 days
I'm so happy and I will run and get her new shoes (thinking of Toyo T1R's...). She deserves it!
So even if we don't know exactly what changed - it is cured. Maybe somebody can shed more light on how it was actually/probably fixed.