Subaru 2004 Impreza Owner's Manual page 289

Starting and operating
tion meter give six levels of indication. The indicator
lights and control dial are linked; when the dial is
turned to change the differential-action limiting factor
(front/rear torque-distribution ratio), the illumination
position of the indicator lights change accordingly.
Turn the dial forward to increase the differential-action
limiting factor. If the white line on the dial reaches the
frontmost position, the center differential will be almost
completely locked and the "LOCK" indicator light will
come on.
7-20
Turn the dial rearward to reduce the differential-action
limiting factor. If the white line on the dial reaches the
rearmost position, the factor will be minimal and the
" " indicator light will come on.
" Do not turn the control dial when a wheel slip-
page occurs. Wait until the wheelspin has been
brought under control or select the auto mode.
" When the vehicle has been fitted with a tem-
porary spare tire or is to be towed, turn the con-
trol dial fully rearward (to minimize the differen-
tial-action limiting factor) or select the auto