RPM is @1500 say 60 Km an hr, when I lift off throttle rpm jumps up aprox 300 rpm. And why does it take so long for rpm to come down?when it does it drops to 1000,i touch accelerator very light-ly it shoots up again 1500 rpm after lifting foot off accelerator. Dose'nt seem to be shifting down into overdrive.

Disconnect the battery for 10 minutes reconnect the battery then start the car and put it into the D postion with your for on the brake for 30 seconds then while still holding the brake put the car the N postion for 30 seconds still holding the brake now put the car back into the D postion for 30 seconds then put the car into the PARK postion and shut it off. Wait 10 second then start it and take it for for a test drive. Make sure the a/c is off and the radio,wipers are off while doing this procedure. This is called an adaptive relearn.