Here's how power memory seats work on your car:

The seat in the video was taken from a Lexus ES300.
The lever arms you see here is responsible for the reclining seat function:


With the seat bottom and back removed, we have clear access to the motors and mechanisms for the recline, tilt, height and slide adjustment.


Inside each motor mechanism is a small spiral gear that gives a gear reduction. There's also a hall effect encoder that consists of a magnet on the spiral gear that rotates. The sensor picks up the number of rotations and stores it as a position in memory.

The sliding mechanism consists of a worm gear (lead screw) on both sides. The motor powers both sides so the chair moves evenly.


Here's what the lumbar mechanism looks like:
Its just a small RC sized motor with a huge gear reduction that drives it:

A side impact airbag was attached to the seat frame. Setting it off gave a small "pop" but nothing too loud.



Enjoy!

 

Great Post and Photos!