2006 Lexus GX470 suspension

OCCUPANT RESTRAINT SYSTEMS
165
Do not attach a microphone or any other device or
object around the area where the curtain shield
airbag activates such as on the windshield glass,
side door glass, front and rear pillars, roof side rail
and assist grips. When the curtain shield airbag
inflates, the microphone or other device or object will
be thrown away with great force or the curtain shield
airbag may not activate correctly, resulting in death
or serious injury.
 Do not hook a hanger , heavy or sharp pointed objects
on the coat hook. If the curtain shield airbag inflates,
those items will be thrown away with great force or
the curtain shield airbag may not activate correctly,
resulting in death or serious injury. When you hang
clothes, hang them on the coat hook directly.
 Do not use seat accessories which cover the parts
where the side airbags inflate. Such accessories may
prevent the side airbags from activating correctly,
causing death or serious injury.
 Do not modify or replace the seats or upholstery of
the seats with side airbags. Such changes may
prevent the side airbag system from activating
correctly, disable the system or cause the side
airbags to inflate accidentally, resulting in death or
serious injury.
 Do not disassemble or repair the front and rear pillars
and roof side rail containing the curtain shield
airbags. Such changes may disable the system or
cause the curtain shield airbags to inflate
accidentally, resulting in death or serious injury.
 Do not modify or change the suspension system.
Such changes may cause the curtain shield airbags
to inflate accidentally, which could result in death or
serious injury . Consult your Lexus dealer about any
repair and modification.
 Do not use tires or wheels other than the
manufacture’s recommended size. Such a use may
cause the curtain shield airbags and seat belt
pretensioners to inflate accidentally, which could
result in death or serious injury. For details, see
“Checking and replacing tires” on page 538.

OCCUPANT RESTRAINT SYSTEMS
166
Do not place luggage heavier than specified on the
roof luggage carrier. Such luggage may cause the
curtain shield airbags and seat belt pretensioners to
inflate accidentally, which could result in death or
serious injury. For details, see “Roof luggage
carrier” on page 107.
Failure to follow these instructions can result in death
or serious injury. Consult your Lexus dealer about any
repair and modification.
If you wish to modify your vehicle for a person with a
physical disability, consult your Lexus dealer. It may
dangerously interfere with the SRS side airbags and
curtain shield airbags operation.
NOTICE
Do not perform any of the following changes without
consulting your Lexus dealer. Such changes can
interfere with proper operation of the SRS side airbag
and curtain shield airbag system in some cases.
 Installation of electronic devices such as a mobile
twoway radio, cassette tape player or CD player
 Modification of the suspension system
 Modification of the structure of the passenger
compartment
 Repairs made on or near the console or front seat
The indicator comes on when the ignition key is turned to
the “ON” position. It goes off after about 6 seconds. This
means the SRS side airbags and curtain shield airbags are
operating properly.
This warning light system monitors the airbag sensor
assembly, front airbag sensors, side and curtain shield airbag
sensor assemblies, curtain shield airbag sensor assemblies,
driver’s seat position sensor, driver’s seat belt buckle switch,
front passenger occupant classification system, “AIRBAG ON”
indicator light, “AIRBAG OFF” indicator light, front passenger’s
seat belt buckle switch, front seat belt pretensioner
assemblies, inflators, warning light, “RSCA OFF” indicator
light, interconnecting wiring and power sources. (For details,
see “Service reminder indicators and warning buzzers” on
page 51 for instructions.)

SECTION 3 – 1
341
STARTING AND DRIVING
Starting and driving
Three−way catalytic converters342
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Engine exhaust caution 343
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Before starting the engine 344
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Ignition switch 345
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Parking brake 347
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How to start the engine 348
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Automatic transmission 349
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Four−wheel drive system 356
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Rear view monitor system 358
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Cruise control 362
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Rear height control air suspension 366
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Electronic modulated suspension 371
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Active traction control system 372
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Vehicle stability control system 375
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Downhill assist control system 377
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Hill −start assist control 380
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Brake system 383
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Tire pressure warning system 387
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Brake pad wear limit indicators 394
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Limited −slip differential 395
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STARTING AND DRIVING
366
REAR HEIGHT CONTROL AIRSUSPENSION
This rear height control air suspension controls the
vehicle height depending on the vehicle driving condition.
Select your desired height among the “HI” (high), “N”
(normal) and “LO” (low) modes with the height select
switch.
(a) Vehicle height modes
“N” (normal) mode: The vehicle height in this mode is
standard. Regardless of the number of occupants or the
luggage loading condition, the vehicle height is always
automatically adjusted to a fixed height in any mode while the
engine is running.
This mode is suitable for ordinary driving. “HI”
(high) mode: The vehicle height is about 40 mm (1.6 in.)
higher at the rear than the “N” mode height.
This mode is suitable when driving on the bumpy roads and
through water.
However, when the vehicle speed exceeds about 30 km/h (19
mph) or over in the “HI” mode, the “N” mode is automaticall\
y
selected.
CAUTION
The “HI” mode should be used for severe offroad
driving condition only. As the vehicle’s center of gravity
is higher in this setting, the vehicle may become
unstable when turning abruptly resulting in accident.
“LO” (low) mode: The vehicle height is about 20 mm (0.8 in.)
lower at the rear than the “N” mode height.
This mode allows you easy access to the vehicle (getting in and
out) and easy loading and unloading operation.
This mode is available when the vehicle speed is under about
12 km/h (7 mph).

STARTING AND DRIVING
367
NOTICE
Use the “LO” mode when the vehicle is stopped.
Otherwise, when the vehicle speed exceeds about 12
km/h (7 mph), “N” mode is selected automatically. So
be careful when you drive in any place where the
overhead height is limited.
(b) Vehicle height mode changing condition
To change the vehicle height, it is necessary to meet the
following conditions.
The engine should be running.
 The height control “OFF” indicator light should go off.
 When selecting a mode, there is a vehicle speed limit. Refer
to the following table.
Yes = The mode can be selected.
No = The mode cannot be selected.
“LO”
mode“N”
mode“HI”
mode
Under about
12 km/h (7 mph)Ye sYe sYe s
Under about
30 km/h (19 mph)NoYe sYe s
About 30 km/h
(19 mph) or overNoYe sNo
In the following cases, the rear height control suspension
will not operate.
 The underbody of the vehicle has touched the surface on
bumpy roads.
 The area around the rear suspension is coated with ice.
If the vehicle is moved to its usual location or the ice is removed
and the height select switch is pressed, the vehicle height
control cannot be operated. In this case, turn off and restart the
engine, then push the control switches.
(c) Vehicle height adjustment
1Higher2Lower
To change the mode, push the height select switch on
either side of “ ” (higher) or “
” (lower).

STARTING AND DRIVING
368The height control indicator light indicates which mode is
selected. (See “(e) Height control indicator light” described
below.)

Selecting the “HI” mode
Push the height select switch on the “ ” side when the vehicle
speed is under about 30 km/h (19 mph).
To change the “N” mode to “HI”: Push the switch once.
To change the “LO” mode to “HI”: Push the switch twice. It
takes about 30 seconds until the “LO” mode changes to the “HI”
mode.
 Selecting the “N” mode
To change the “HI” mode to “N”: Push the height select
switch on the “
” side once.
To change the “LO” mode to “N”: Push the height select
switch on the “ ” side once.
 Selecting the “LO” mode
Push the height select switch on the “
” side while the vehicle
is stopped.
To change the “N” mode to “LO”: Push the switch once.
To change the “HI” mode to “LO”: Push the switch twice.
Even if the engine is stopped while the vehicle height is being
lowered, the operation continues for up to 25 seconds. If within
this 25 seconds, any of the side doors or the back door is
opened, operation will continue for a further 15 seconds.
NOTICE
 If the vehicle height is changed frequently when the
vehicle is heavily loaded, the compressor may
overheat causing the vehicle height adjustment
operation to stop.
 Before you lower the vehicle height with the height
select switch, check under the vehicle to make sure
nothing to damage the vehicle or no one to be injured
is there and that the underbody of the vehicle does
not touch the ground.
 After unloading, the height of a vehicl e equipped with
the rear height control air suspension becomes
slightly higher than the normal vehicle height. Take
sufficient care where the overhead height is
restricted.
 Do not select the “LO” mode in the bumpy roads. If
the underbody of the vehicle touches the rugged
road surface, the vehicle may be damaged.

STARTING AND DRIVING
369
(d) Turning off the rear height control airsuspension
To turn off the rear height control air suspension with the
vehicle stopped, push the “HEIGHT CONTROL OFF”
switch. The height control “OFF” indicator light comes on
and the vehicle height is fixed in the same mode as the
height control switch is pushed.
This status is memorized in the system even after the engine
is stopped.
If you push the switch again, the height control “OFF” indicator
light goes out and the rear height control air suspension is
turned on.
Even after the rear height control air suspension is turned off
with the “HEIGHT CONTROL OFF” switch, if the vehicle speed
exceeds 30 km/h (19 mph), the rear height control air
suspension automatically selects the “N” mode.
CAUTION
If you drive through deep water over about 700 mm (28
in.) in depth, put the vehicle height in the “HI” mode with
the height select switch and then turn off the rear height
control air suspension by pushing the “HEIGHT
CONTROL OFF” switch.
NOTICE
 When jacking up or installing tire chains, be sure to
turn off the rear height control air suspension with
the “HEIGHT CONTROL OFF” switch and stop the
engine. Otherwise, the vehicle height may change
because of the automatic leveling function resulting
in accident.
 If your vehicle must be towed, put the vehicle height
in the “N” mode and turn off the rear height control air
suspension. Otherwise, the vehicle height may
change because of the automatic leveling function
resulting in accident.
 If your vehicle gets ditched, turn off the rear height
control air suspension with the “HEIGHT CONTROL
OFF” switch. Otherwise, the vehicle height may
change because of the automatic leveling function
resulting in accident.

STARTING AND DRIVING
370
(e) Height control indicator lights
1Height control indicator lights
2Height control “OFF” indicator light
When the ignition switch is turned on, all the indicator lights
come on. Only the indicator light showing the present mode
remains on and all other lights go off after a few seconds. This
means the system operates correctly.
When you change the vehicle height mode, the indicator lights
change as follows:
When changing the vehicle height from the “N” mode to
“HI”:
1. The “N” mode indicator light goes off and the “HI” mode
indicator light blinks.
2. After the vehicle height control reaches the “HI” mode, the
“HI” mode indicator light remains on. If the underbody of the vehicle has touched the surface on
bumpy roads or the area around the rear suspension is
coated with ice, the height control suspension will not
operate and the indicator lights change as follows:
1. The present mode indicator light goes off and the selected
mode indicator light blinks.
2. The selected mode indicator light goes off. (The vehicle
height does not change.) The present mode indicator light
comes on again.
Height control “OFF” indicator light:
When the ignition
switch is turned on, this light comes on. If it goes out after a few
seconds, the rear height control air suspension operates
correctly. If you push the “HEIGHT CONTROL OFF” switch,
the rear height control air suspension is turned off. The height
control “OFF” indicator light comes on.
In the following cases, there is a problem somewhere in the
rear height control air suspension. Although there is no
problem to continue normal driving, have the rear height
control air suspension checked by your Lexus dealer as soon
as possible.
 The height control “OFF” indicator light does not come on
when the ignition switch is turned on.
 The height control “OFF” indicator light blinks.