Lexus 2003 LS Owner's Manual page 296

STARTING AND DRIVING
Anti–lock brake system is not designed to shorten the
stopping distance: Always drive at the moderate speed
and maintain a safe distance from the vehicle in front of
you. Compared with vehicles without an anti–lock
brake system, your vehicle may require a longer
stopping distance in the following cases:
A Driving on rough, gravel or snow–covered roads.
A Driving with tire chains installed.
A Driving over the steps such as the joints on the road.
A Driving on roads where the road surface is pitted or
has other differences in surface height.
Install all 4 tires of specified size at appropriate
pressure: The anti–lock brake system detects vehicle
speeds using the speed sensors for respective wheels'
turning speeds. The use of tires other than specified
may fail to detect the accurate turning speed resulting
in a longer stopping distance.
282
"ABS" warning light
31L141a
The light comes on when the ignition switch is turned to the
"ON" position. If the anti–lock brake system and the brake
assist system work properly, the light turns off after a few
seconds. Thereafter, if either of the systems malfunctions, the
light comes on again.
When the "ABS" warning light is on (and the brake system
warning light is off), the anti–lock brake system, the brake
assist system, the traction control system and/or the vehicle
skid control system do/does not operate, but the brake system
still operates conventionally.
When the "ABS" warning light is on (and the brake system
warning light is off), the anti–lock brake system does not
operate so that the wheels could lock up during a sudden
braking or braking on slippery road surfaces.