2012 Lexus GX460 stop start

318
2-4. Using other driving systems
GX460_U.S.A. (OM60J00U)
■When HI mode is selected
The vehicle height will change to N mode when driving at the speeds of 18 mph (30
km/h).
Even if vehicle speed is then reduced to under 18 mph (30 km/h), height will not
return to HI mode.
■When LO mode is selected
The vehicle height will change to N mode when vehicle speed exceeds 7 mph
(12 km/h).
Even if vehicle speed is then reduced to under 7 mph (12 km/h), height will not
return to LO mode.
■Automatic leveling function
Regardless of the number of occupants and the luggage load, vehicle height in any
mode is always adjusted to a fixed height by the automatic leveling function.
■The rear height control air suspension will not operate in the following cases:
●The underbody of the vehicle is touching the surface of the road.
●The area around the suspension is covered with ice.
■Even if you hear an operating noise
This does not indicate a problem in the rear height control air suspension.
■Parking and stopping tips
●If you immediately stop the engine after off-road driving, or park the vehicle for
a long time, the vehicle height may gradually lower. When parking, make sure
there is nothing under the vehicle that may come in contact with the underbody.
The vehicle will return to the set height when the engine is started.
●The vehicle height may change as the temperature changes when the engine is
stopped. The vehicle will return to the set height when the engine is started.

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2-4. Using other driving systems
2
When driving
GX460_U.S.A. (OM60J00U)
■When lowering the vehicle
In order to prevent the vehicle height from rising as occupants leave the vehicle,
lowering control will occur for a short while after the engine has been stopped.
■The rear height control air suspension failure warning
●If a malfunction occurs in the rear height control air suspension, N mode is auto-
matically selected. However, the system may not switch to N mode depending
on the location of the malfunction.
●The warning message is displayed on the multi-information display, and the rear
height control air suspension cannot be activated until the malfunction is cor-
rected.
Stop the engine and start it again. If the warning message turns off, the system is
operating correctly. If the warning message continues to be displayed, have
your vehicle inspected by your Lexus dealer as soon as possible.
CAUTION
■The rear height control air suspension must be turned off
Be sure to observe the following precautions. Otherwise, the automatic leveling
function may cause vehicle height to change, and you may catch part of your body
in the vehicle, resulting in an accident:
●When jacking up the vehicle, installing tire chains or tying the vehicle with chains/
wires for transportation via flat bed truck, turn off the rear height control air sus-
pension and stop the engine.
●When the vehicle must be towed or disconnecting a trailer, put the vehicle height
in N mode and turn off the rear height control air suspension.
●When the vehicle is stuck, turn off the rear height control air suspension.

325
2-4. Using other driving systems
2
When driving
GX460_U.S.A. (OM60J00U)
■When the four-wheel drive control switch can be operated
●The “ENGINE START STOP” switch is in IGNITION ON mode.
●The shift lever is in the N position.
●The vehicle is stopped completely.
■The low speed four-wheel drive indicator light
●The indicator light blinks while switching between H4 and L4.
●If the low speed four-wheel drive indicator light continues to blink when you
operate the four-wheel drive control switch to the H4 or L4 position, stop the
vehicle completely, shift the shift lever securely into N and then operate the
switch again.
●If the shift lever is moved before the low speed four-wheel drive indicator turns
on/off, the transfer mode may not be shifted completely. The transfer mode dis-
engages both the front and rear drive shafts from the powertrain and allows the
vehicle to move regardless of the shift position. (At this time, the indicator blinks
and the buzzer sounds.)
Therefore, the vehicle is free to roll even if the shift lever is in P. You or someone
else could be seriously injured. You must complete the shifting of the transfer
mode and confirm that the indicator light has turned off (H4) or turned on (L4).
●If the engine coolant temperature is too low, the four-wheel drive control system
may not be able to shift. When the engine is warmer operate the switch again.
If the indicator continue to blink even if doing so, have the vehicle inspected by your
Lexus dealer as soon as possible. There may be a trouble in the four-wheel drive
system.

326
2-4. Using other driving systems
GX460_U.S.A. (OM60J00U)
■When the center differential lock/unlock switch can be operated
The “ENGINE START STOP” switch is in IGNITION ON mode.
■The center differential lock indicator light
●The indicator light blinks while locking/unlocking the center differential.
●If the center differential lock indicator light blinks and the buzzer sounds when
the center differential is locked, stop the slipping or spinning and push the
switch again.
If the indicator continue to blink even if doing so, have the vehicle inspected by your
Lexus dealer as soon as possible. There may be a trouble in the four-wheel drive
system.
■Locking/unlocking the center differential
●When the four-wheel drive control switch is in L4 with the center differential
locked, VSC is automatically turned off. (The center differential lock and VSC
OFF indicator light will come on.)
●If the operation is not completed, the center differential lock indicator blinks. If
the indicator light does not turn off when unlocking the center differential, drive
straight ahead while accelerating or decelerating, or drive in reverse.
●Avoid turning suddenly while the center differential is locked. If you do turn sud-
denly, the difference in turning speeds between the front and rear wheels may
have a similar effect to braking, thus making driving difficult.

330
2-4. Using other driving systems
GX460_U.S.A. (OM60J00U)
■Automatic system cancelation
In the following situations, the system is canceled automatically:
At that time, the buzzer will sound, the slip indicator turns off, and the Crawl Con-
trol indicator flashes.
A notification will be displayed on the multi-information display for several seconds.
(→ P. 700)
●When the shift lever is moved to P or N.
●When the four-wheel drive control switch is in H4.
●When the driver’s door is opened.
When turning off Crawl Control while traveling, stop the vehicle before the Crawl
Control indicator turns off, or drive extremely carefully.
■Function limit
●In the following situations, you will be able to use brake control to drive downhill
at a fixed low speed, but you will be unable to use engine control to drive uphill
at a fixed low speed.
• When the driving mode is set to second start mode.
• When the vehicle speed is higher than 6 mph (10 km/h).
●In the following situation, engine control and brake control will stop temporarily:
At that time, the Crawl Control indicator flashes.
When the vehicle speed is higher than 15 mph (25 km/h).
■When the Crawl Control system is operated continuously
This may cause the brake actuator to overheat. In this case, the Crawl Control sys-
tem will stop operating, a buzzer will sound, the Crawl Control indicator will turn off
after flashing and the TRAC OFF will be shown on the multi-information display. In
this case, quickly stop the vehicle in a safe place and give the actuator adequate
time to cool off. Refrain from using the system until the message goes off. (The vehi-
cle can be driven normally during this time.)

331
2-4. Using other driving systems
2
When driving
GX460_U.S.A. (OM60J00U)
■If the automatic transmission system overheats
The system will cease operation, a buzzer will sound and a warning message will be
displayed to alert the driver. Stop the vehicle in a safe place until the warning mes-
sage turns off. (→P. 700)
■Sounds and vibrations caused by the Crawl Control system
●A sound may be heard from the engine compartment when the engine is
started or just after the vehicle begins to move. This sound does not indicate that
a malfunction has occurred in Crawl Control system.
●Either of the following conditions may occur when the Crawl Control system is
operating. None of these are indicators that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
■If the slip indicator comes on...
It may indicate a malfunction in the system. Consult your Lexus dealer.
CAUTION
■When using Crawl Control
Do not rely solely on the Crawl Control. This function does not extend the vehicle’s
performance limitations. Always thoroughly check the road conditions, and drive
safely.
■These conditions may cause the system not to operate properly
When driving on the following surfaces, the system may not be able to maintain a
fixed low speed, which may result in an accident:
●Extremely steep inclines.
●Extremely uneven surfaces.
●Snow-covered roads, or other slippery surfaces.

332
2-4. Using other driving systems
GX460_U.S.A. (OM60J00U)
DAC (Downhill Assist Control system)∗
∗: If equipped
The DAC helps to prevent excessive speed on steep downhill slopes.
The system will operate when the vehicle is traveling under 15 mph
(25 km/h) and the four-wheel drive control switch is in the L4 position.
■System operation
Shift the “DAC” switch to ON.
The downhill assist control indi-
cator light comes on and the
system will operate.
When the system is in operation,
the slip indicator light will flash,
and the stop lights/high
mounted stop lights will be lit.
■Turning off the system
Shift the “DAC” switch to OFF while the system is in operation. The
downhill assist control indicator will flash as the system gradually
ceases operation, and will turn off when the system is fully off.
Shift the “DAC” switch to ON while the downhill assist control indi-
cator is flashing to start the system again.

333
2-4. Using other driving systems
2
When driving
GX460_U.S.A. (OM60J00U)
■Operating tips
The system will operate when the shift lever is in a position other than P, however to
make effective use of the system it is recommended that the shift lever be shifted to
2 or 1 range of S mode.
■If the four-wheel drive control switch is in H4
The system does not operate.
■When the downhill assist control system is operated continuously
This may cause the brake actuator to overheat. In this case, the downhill assist con-
trol system will stop operating, a buzzer will sound and the DAC indicator will start
flashing, and the TRAC OFF will be shown on the multi-information display. Refrain
from using the system until the DAC indicator stays on and the message goes off.
(The vehicle can be driven normally during this time.)
■Sounds and vibrations caused by the DAC
●A sound may be heard from the engine compartment when the engine is
started or just after the vehicle begins to move. This sound does not indicate that
a malfunction has occurred in DAC.
●Either of the following conditions may occur when the DAC is operating. None
of these are indicators that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
■System malfunction
●The DAC indicator does not come on when the “ENGINE START STOP”
switch is turned to IGNITION ON mode.
●The “DAC” indicator does not come on when the “DAC” switch is pressed.
●The slip indicator comes on.
In the above cases, have your vehicle checked by your Lexus dealer.