Lexus LX 470 Owner's Manual page 242

STARTING AND DRIVING
You may hear a sound in the engine compartment for a few
seconds when the engine is started or just after the vehicle is
started. This means that the active traction control system is
in the self−check mode, and does not indicate malfunction.
When the active traction control system is operating, you may
feel vibration or noise of your vehicle, caused by operation of
the brakes. This indicates the system is functioning properly.
When getting the vehicle out of mud or new snow, etc., the
active traction control system will help operate to prevent the
wheels from spinning.
31X064b
"Active traction control system failure warning
This light warns when there is a problem somewhere in the
active traction control system or vehicle skid control system.
If the "VSC/TRAC" warning light comes on, have your vehicle
checked by your Lexus dealer as soon as possible.
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The brake actuator temperature increases during the active
traction control system or vehicle skid control system
operating. If the brake actuator temperature becomes too high
while the active traction control system or vehicle skid control
system is operating, a buzzer will start to sound intermittently
to indicate that the active traction control system can no longer
operate. In this case, immediately stop your vehicle at a safe
place. If the system continues to operate, the buzzer sound
changes from intermittent to continuous. (The continuous
buzzer sound will stop after about 3 seconds.) At the time the
"VSC/TRAC" warning light will come on and the active traction
control system temporarily stops operating in order to protect
the brake actuator. (Although the active traction control
system does not operate, there is no problem to continue your
driving.) The system will be automatically restored after a short
time and "VSC/TRAC" warning light goes off if the accelerator
pedal is released.
When the "ABS" warning light comes on, the active traction
control system is not operating.
The "VSC/TRAC" warning light will come on when the ignition
key is turned to "ON", and will go off after a few seconds.
The "VSC/TRAC" warning light may stay on for 60 seconds
after the ignition key is turned to the "ON" position. It is normal
if it goes off after a few seconds.
Depressing the brake pedal repeatedly may turn on the
"VSC/TRAC" warning light. It is normal if it goes off after a few
seconds.
When the "VSC/TRAC" warning light comes on, the active
traction control system is not operating, but there is no problem
if you continue to drive.