08 Auto not changing down consistently

[terry.s]

I just noticed today the auto in our 08 X3 is acting a little erratically.

I first notice on a long hill climb on the freeway with the cruise on. Rather than down shift to maintain speed, the car just lost momentum and speed. I manually changed down and accelerated away nicely, then flicked it back to auto mode and the car stayed in the correct gear for the climb and continued on its way on the cruise control.

I then noticed once i got off the freeway that if i didn't aggressively accelerate, the car wouldn't change gear down when required.

if I change manually, the gears are selected fine and all feels ok.

any ideas?

The car is a 2,0l diesel with 126000km, and just had the major service 2 at BMW two weeks ago.

thanks

terry