You may have to unsolder that chip and restore all traces around the affected area - there was a repair kit on eBay not too long ago.
My personal success with repairing these controllers - 2 out of 3 working, 1 absolutely not (worse even, it would occasionally move the mirrors cock-eyed, and it would not let me adjust them unless the driver door is open).
What a flaming junk these are.
Come to think of it, the only other manufacturer using these was Rolls Royce.