I've had the same problem happen occasionally. Look under the seat at the wiring harness located in the front towards the door. Lots of wires coming out of a white plastic plug. Grab it and make sure it is connected well. Usually works on mine the few times I've had a problem.

 

My seat memory never worked. Turned out to be the buttons on the doors. Replaced under warranty. If yours is out of warranty, I'd look there first.

 

I can save the seat position on 1 , 2 and 3 and I can see on the dashboard the message " memory saved" but when I press on 1 or 2 or 3 , nothing happen