Lexus ES300 Owner's Manual page 259

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 the vehicle skid
control system do 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.
If either of the following conditions occurs, this indicates
a malfunction somewhere in the parts monitored by the
warning light. Contact your Lexus dealer as soon as
possible to service the vehicle.
D The light does not come on when the ignition key is turned
to the "ON" position, or remains on.
D The light comes on while you are driving.
A warning light turning on briefly during operation does not
indicate a problem.
CAUTION
If the "ABS" warning light remains on together with the
brake system warning light, immediately stop your
vehicle at a safe place and contact your Lexus dealer.
In this case, not only the anti lock brake system will fail
but also the vehicle will become extremely unstable
during braking.
STARTING AND DRIVING
Drum in disc type parking brake system
Your vehicle has a drum in disc type parking brake system.
This type of brake system needs bedding down of the brake
shoes periodically or whenever the parking brake shoes
and/or drums are replaced.
Have your Lexus dealer perform the bedding down.
Brake assist system (vehicles with vehicle
skid control system)
When you slam the brakes on, the brake assist system
judges as an emergency stop and provides more powerful
braking for a driver who cannot hold down the brake pedal
firmly.
When you slam the brakes on, more powerful braking will be
applied. At this time, you may hear a sound in the engine
compartment and feel the vibrations of the brake pedal. This
does not indicate a malfunction.
The brake assist system becomes operative after the vehicle
has accelerated to a speed in excess of approximately 10 km/h
(6 mph). It stops operating when the vehicle decelerates to a
speed below approximately 5 km/h (3 mph).
For an explanation of this system's warning light, see "ABS
warning light" on page 55.
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