Lexus GX470 2004 Owner's Manual page 413

STARTING AND DRIVING
NOTICE
Use the "LO" mode when the vehicle is stopped.
Otherwise, when the vehicle speed exceeds about 12
km/h (7 mph), "N" mode is selected automatically. So
be careful when you drive in any place where the
overhead height is limited.
(b) Vehicle height mode changing condition
To change the vehicle height, it is necessary to meet the
following conditions.
D The engine should be running.
D The height control "OFF" indicator light should go off.
"LO"
mode
Under about
Yes
12 km/h (7 mph)
Under about
No
30 km/h (19 mph)
About 30 km/h
No
(19 mph) or over
396
D When selecting a mode, there is a vehicle speed limit. Refer
to the following table.
Yes = The mode can be selected.
No = The mode cannot be selected.
"N" "HI"
mode mode
Yes Yes
Yes Yes
Yes No