flashing 4th and D Tiptronic

[tonythetiger]

2002 tip, 986 S with 80K

Flashing 4th and D after warm up, however transmission works fine and the normal lights come back in a minute or so, go to 4th and D again, etc as I drive. Automatic and manual function fine, just dont get the feedback in the dash lights when its out.

I have heard this could be the transmission’s coolant vacuum valve. Does this circulate coolant through the transmission? That seems to be the simple fix and makes sense.

I had the transmission serviced, new fluid, filter etc about 6 months ago, but the problem didn't completely resolve. Now with the warmer weather, I'm thinking I should iron out this issue.
I have a durametric scanner, but it only shows alarm fault codes (historic, none present now) to be honest, I am not sure I'm using the durametric to its potential, it seems pretty lame when I do the short test on all modules, so I would welcome advice on this as well.

would a faulty coolant vacuum valve potentially lead to heat issues with the tiptronic, manifesting in the 4th and D flashing?