Toyota land cruiser prado Owner's Manual page 167

The slip indicator light and downhill assist
control system indicator light come on for
a few seconds when the engine switch is
turned to "ON". If any of the indicator
lights does not come on when the engine
switch is turned on, contact your Toyota
dealer.
158
Vehicles with 1GR−FE and 1KD−FTV en-
gines—
The brake actuator temperature increases
during continuous operation of the follow-
ing systems.
Active traction control system
D
Vehicle stability control system
D
Downhill assist control system
D
Hill−start assist control system
D
If the brake actuator temperature becomes
too high while any of the systems is oper-
ating, a buzzer will start to sound intermit-
tently to indicate that the downhill assist
control system can no longer operate. In
this case, stop your vehicle immediately at
a safe place.
If the system continues to operate, the
buzzer sound changes from intermittent to
continuous. (The continuous
sounds for about 3 seconds.)
At this time, the slip indicator light will
come on, the downhill assist control sys-
tem indicator light flash and the downhill
assist control system temporarily stops
operating in order to protect the brake
actuator. (Although the downhill assist
control system does not operate, it is no
problem to continue your driving.) The
system will be automatically restored after
a short time and the slip indicator light
and the downhill assist control system in-
dicator light go out.
buzzer