The ATF should be changed at intervals of 160.000km or 100.000mls. The revised Maintenance booklet states this.

Back many years ago, there was a software update that slightly alleviated this problem, where 3rd and 4th gear hold gears too long when going up a gradient. Obviously you are out of warranty, but if you are willing to pay, you could ask and see if the dealer still has the EGS update and how much they charge for the service.