Lexus 2003 LS Owner's Manual page 128

COMFORT ADJUSTMENT
16L262a

Upper lumbar support
Push the upper lumbar support control switch on either
side.
The amount of upper lumbar support will change while the
switch is pushed.
114
A Front passenger's seat
16L354a
Push the control switch on either side.
The amount of lumbar support will change while the switch is
pushed.