Hi,
If you drained the transmission and torque converter, it would likely need more fluid.
Now, the codes you have are interesting. The one for the ECT wouldn't have anything to do with a rough shift. The other code indicates that the transmission is being told to do multiple things at the same time.
Go to the transmission range sensor and inspect the connector to make sure it isn't pinched. I have a feeling the connector wiring/harness is pinched and shorting causing the transmission to go into multiple gears at the same time.
Also, take a look at the diagram below. You may find it helpful as well.
Take care,
Joe
See pic below.
Image (Click to make bigger)
Wednesday, April 5th, 2023 AT 8:27 PM