Lexus 2003 LS Owner's Manual page 256

STARTING AND DRIVING
(f) Good driving practice
A If the transmission repeatedly shifts up and down between
fourth and overdrive gears when climbing a gentle slope,
shift the selector lever to the "4" position. Be sure to shift the
selector lever to the "D" position after climbing the slope.
A When towing a trailer, in order to maintain efficient engine
braking and electrical charging performance, do not use
overdrive. The selector lever must be in the "4" position.
CAUTION
Always keep your foot on the brake pedal while stopped
with the engine running. This prevents the vehicle from
creeping.
NOTICE
Always use the brake pedal or the parking brake to hold
the vehicle on an upgrade. Do not attempt to hold the
vehicle using the accelerator pedal, as this can cause
the transmission to overheat.
242
(g) If you cannot shift the selector lever
If you cannot shift the selector lever even though the brake
pedal is depressed, use the shift lock override button. For
instructions, see "If you cannot shift automatic transmission
selector lever" on page 320.