Originally Posted by Lawaia

Dealer finally solved the shifting issue, and believe it or not, the cause was a faulty wiring harness that attaches to the valve body inside the tranny. The X now shifts as it should!!
BMW has published a TSB describing these exact same problems, but NOT for the X5. It's for another model that shares the same tranny as ours.
Good info to have in case any of you experience these symptoms.