I dont know if this works on E53. But it sure works on E60. My e60 now drives like a different vehicle, totally reponsive.
Reset AT Software process:
-Turn key on positon 2 (all accessories are on but doesn't start the car)
-Floor the accelerator for 30 seconds (you will hear a click)
-Release the accelerator turn the key off.
-Restart the car as usual.
Your AT self learning has been RESET. The car will drive like it just rolled out of dealer.
It works amazingly well on E60. Not sure about E53.

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2002 X5 3.0 Siena Red
Premium, Cold Weather, Rear Climate Packages, 19" Wheels
Aluminum Running Boards, Clear Tail Lights, Clear Side Markers
Titanium Kidney Grills, Titanium Trunk Lid, Xenon Headlights
4.6is X5 exhausts, 35% Tint, Aluminum Pedals
2005 530I Mystic Blue
Premium Package, Sport Package, Xenon Headlights
18" Sport Wheels, 35% Tint all around
Mods to come: M-Tech Front Bumper, M5 Side Skirts, M5 Rear Bumper
Quad Exhausts, Style 172 19" Wheels