Mr. CVE

The car drives fine when cruising.
When you give it everything ( race someone ) sometimes the buttons don't always work.
or they do but are slow, especially 2-3.
last time, it was banging the limiter ( i think ) a bit after that the trans was really hard shifting.
and would shift 1-2-3-5-4
in auto mode.

This was on the same drive home.
so you are sitting in D say 60 mph, and it is revving, you press the down button on the steering wheel and it goes into 5th !
press up, to D and it drops to 4th gear and revs again.

i get home, turn car off , in the morning it is fine again, although maybe a little harsh on the shifts.
I cruise 99% of the time.

It has a high stall, and hasn't been touched in about 10,000 miles. Fluid was changed back then and was fine.
Car is worked , about 500hp @ wheels

Any suggestions ?? please ?

Mr. CVE

Maybe I will take the car in to get the trans serviced.
What things tend to die on these ? I may get them changed at the same time.

SICAMG

Conductor plate is real common but it sounds like you have a software issue. I will dig a little and see what I can find.

Mr. CVE

Thank you, It didn't used to do it. That's why i am thinking it could be a wearing component.

BoostedAero

I like these games...

What does your fluid look like?

Could the control overlap sleeve that allows the shift to 3rd be in a state where it is sticking then blowing open shifting harder that it should?

SICAMG

Me to. I would think a stuck valve would be stuck cold or hot. The next morning he says its fine.
Mr. CVE you will need to really pay close attention to what it is doing, does it work correctly in "S" mode automatically? Also if your banging the limiter is it because the trans is slipping and you do not feel it?

BoostedAero

How many miles are on the car?

The more I think about the issue it begins to sound like a communication issue with the Trans. With your statements about hunting and odd shift patterns.

I know it would be a PITA... Can get a passenger to film and host on YouTube to share?

(Insert picture worth words saying here)

I would start with looking for either a wicking issue to the TCU. Replace the ECP(possibly Faulty Electronic Control Plate? The bit with the speed sensors between the valve body and the trans (sorry blanking on the name just back from a concert).

Your TCU may be failing can you test with another E55 TCU to eliminate that as the issue?

Add more info please

SICAMG

Conductor plate is what you are thinking of Boosted. They can do some strange things when they go bad.