Well the system works like this: You have a body controller and this unit makes the control, as far as I know, of the internal electric, like the lock system, the windows and the seats.
You have an electrical harness, which goes from the switch where you can choose the memory setting for the seats, to this controller and as well from the controller, to the seats where is, as far as I know, another controller below the seat, to control the motors which move the seat.
I guess the easiest way would be, if you have electrical knowledge, then get a plan and check at the connectors, if you have the correct values for Voltage and that the cables have no breaks in the wiring harnesses.
If you don't have a plan and aren't an electronics genius, you can definitely remove both seats and measure where you have 12 volts on the plug, because power has to arrive at the seat first.
I think since the seats are relatively similar in function, they will have pretty much the same plugs. With a little logic, you can get to the point and if you have 12 volts somewhere or on several pins on a wiring harness on the passenger side and you don't have 12 volts anywhere on your driver's seat, then you know, that you have to look for the reason.
If everything is equal, maybe your controller of the seat is defective.