I have a strange problem with my alphard AH20 2008 2.4 Petrol. Will try to explain what happens. When on cruise, the car encounters a moderate hill the gears change down and the revs rise considerably. Today ex. From 1500 to c 3500. On the same hill when cruise off box changes normally revs increase by 1500 to 2200. If on the hill when cruise switched off when revs high they drop to 2200. Anyone had this issue or know where to start looking.