2008 Lexus GX470 Operating the lights and windshield wipers / LEXUS 2008 GX470 OWNER'S MANUAL (OM60D82U)

153
2-4. Using other driving systems
2
When driving
■If the vehicle height does not change
If the area around the rear suspension is coated with ice, or the undercarriage has
come into contact with the road surface, the rear height control suspension will not
operate. In this case, the indicator lights will change as follows:
●The current mode indicator light will turn off, and the target mode indicator light
will begin flashing.
●The target mode indicator light will turn off, and the original mode indicator light
will be lit once more. (The vehicle height does not change.)
If the rear height control air suspension cannot be operated even after removing
the ice or progressing to a smooth driving surface, turn off and restart the engine.
■ Parking and stopping tips
●If you immediately stop the engine after of f-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.
■When lowering the vehicle
Even if the engine is stopped while the ve hicle height is being lowered, operation
will continue for up to 25 seconds. If any of the side doors or the back door is
opened within this 25 seconds, operatio n will continue for a further 15 seconds.
■ Rear height control failure warning
●If a malfunction occurs in the rear height control air suspension, normal mode is
automatically selected.
The height control “OFF” indicator will blink, and the vehicle height control can-
not be activated until the malfunction is corrected. Have the vehicle checked at
your Lexus dealer as soon as possible.
●If the height control “OFF” indicator li ght does not come on when the engine
switch is turned to the “ON” position, there is a malfunction in the rear height
control air suspension. You can continue normal driving, however have the vehi-
cle checked by your Lexus dealer as soon as possible.

154
2-4. Using other driving systems
CAUTION
Failure to observe the following precautions may result in an accident.
■ Using the “HI” (high) mode
This mode should only be used for rough off-road conditions. Because the vehicle’s
center of gravity is higher when in the high mode, the vehicle may become unstable
when turning abruptly.
■When loading cargo on the roof luggage carrier
Do not select the “HI” (high) mode. Because the vehicle’s center of gravity is higher
when in the high mode, the vehicle may become unstable when turning abruptly
and unexpected loss of control or vehicle rollover may occur.
■When jacking up the vehicle or installing tire chains
Turn off the rear height control air suspension and stop the engine, otherwise the
vehicle height may change due to the automatic leveling function.
■ When driving through water deeper than 28 in. (700 mm)
Select the “HI” (high) mode, turn off the re ar height control air suspension and drive
at 19 mph (30 km/h) or slower. Otherwise, the vehicle height may change due to
the automatic leveling function.
■If your vehicle must be towed
Put the vehicle height in the normal mode and turn off the rear height control air
suspension, otherwise the vehicle height may change due to the automatic leveling
function.
■If your vehicle becomes stuck in a ditch
Turn off the rear height control air susp ension, otherwise the vehicle height may
change due to the automatic leveling function.

155
2-4. Using other driving systems
2
When driving
NOTICE
■To avoid damage to the vehicle
●If in the low mode, the vehicle automatically shifts to the normal mode (vehicle
height is raised) when the engine is started. Take care when overhead height is
limited.
●After unloading, the vehicle height may be slightly higher than normal. Take care
when overhead height is limited.
●Before lowering the vehicle height, check that no-one is under the vehicle and
the area is free of obstructions. Also check that the underbody of the vehicle will
not touch the ground.
●Do not select the low mode when drivin g on bumpy roads, as the underbody of
the vehicle may contact the road surface.
■ Avoid rapid changes to the vehicle height when the vehicle is heavily loaded
As the compressor may overheat, causing the vehicle height adjustment operation
to stop.

156
2-4. Using other driving systems
Electronic modulated suspension
■Driving mode
●Mode is suitable for ordinary driving.
●Mode or is suitable for heavy load or driving on a unpaved road.
●With the four-wheel drive control lever at “L”, the damping effect suitable for off-
road driving will be provided.
The electronic modulated suspension controls the suspension according to
the road and driving conditions. Selected driving mode allows for good
riding comfort and stability.
For driving on a bumpy road
For ordinary driving such as
in the city traffic
For moderate high speed
driving
For sporty type driving such
as on winding mountain
roads and high speed driving.
Soft Hard

157
2-4. Using other driving systems
2
When driving
DAC (Downhill Assist Control system)
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 lever is in the “L” position.
■System operation
Press the “DAC” switch. The
indicator will come 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
Press the “DAC” switch while the system is in operation. The indica-
tor will flash as the system gradua lly ceases operation, and will turn
off when the system is fully off.
Press the “DAC” switch while the indicator is flashing to start the
system again.

158
2-4. Using other driving systems
■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 “L”.
■If the four wheel drive control lever is in “H”
The system will not operate.
■If the brake system overheats
The system will cease operation and a bu zzer will sound to alert the driver.
Stop the vehicle in a safe place. (There is no problem with continuing normal driv-
ing.)
■System malfunction
●The “DAC” indicator does not come on when the engine switch is turned to the
“ON” position.
●The “DAC” indicator does not come on when the “DAC” switch is pressed.
In the above cases have your vehicle checked by your Lexus dealer.
CAUTION
■The system may not operate on the following surfaces, which may lead to an acci-
dent causing death or serious injury.
●Slippery surfaces such as wet or muddy roads
●Icy surfaces
●Unpaved roads

159
2-4. Using other driving systems
2
When driving
Driving assist systems
To help enhance driving safety and performance, the following systems
operate automatically in response to various driving situations. Be aware,
however, that these systems are supplementary and should not be relied
upon too heavily when operating the vehicle.
■ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if
the brakes are applied while driving on a slippery road surface.
■Brake Assist
Generates an increased level of braking force after the brake pedal is
depressed, when the system detects a panic stop situation.
■VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or turning on
slippery road surfaces.
■ Active traction control
Maintains drive power and prevents the 4 wheels from spinning when
starting the vehicle or accelerating on slippery roads.
■Hill-start assist control
Helps prevent the vehicle from rolling backwards when starting on an
incline or slippery slope. It operates for approximately 5 seconds at maxi-
mum.
■ Limited Slip Differential
Transfers drive power to the rear tires when front tires spin, and vice versa,
in order to improve traction.
■Kinetic Dynamic Suspension System (if equipped)
Kinetic Dynamic Suspension System helps to significantly enhance han-
dling response by reducing roll stiffn ess of the suspension stabilizer bars
through means of a hydraulic control system.

160
2-4. Using other driving systems
When the VSC/TRAC/hill-start assist control systems are operatingIf the vehicle is in danger of slip-
ping, rolling backwards when
starting on an incline, or if the rear
wheels spin, the slip indicator light
flashes to indicate that the VSC/
TRAC/hill-start assist control sys-
tems have been engaged.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
The stop lights and high mounted
stoplight turn on when the hill-start
assist control system is operating.
The slip indicator light flashes as
well when ABS is operating.
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC and hill-start
assist control systems
●A sound may be heard from the engi ne 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 any of these systems.
●Any of the following conditions may occur when the above systems are operat-
ing. None of these indicates 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.
• The brake pedal may pulsate slightly after the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.
■Hill-start assist control is operational when
●The shift lever is in any of the positions “D”, “4”, “3”, “2” or “L”.
●The brake pedal is not depressed.