[Meeni]

In ISTA-D, you do a functionnal job for changing the trans oil. It will drive you through getting the oil at the appropriate temperature to check the level etc. At this point you simply click next and it will do the software reset as appropriate before letting you know you did a good job.

If problem persist you may need new solenoids, or have a problem with oil pressure due to one of the internal plastic seals being cracked. The big one that looks like 2 squares next to one another is known to fail often.