air suspension Lexus GX470 2004 Audio System / LEXUS 2004 GX470 FROM JAN. 2004 THROUGH JUL. 2004 PROD. (OM60A87U) User Guide

SECTION 3 ± 1
368
STARTING AND DRIVING
Starting and driving
Three-way catalytic converters369
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Engine exhaust caution 372
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Before starting the engine 374
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Ignition switch with steering lock 374
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Parking brake 376
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How to start the engine 377
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Automatic transmission 378
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Four-wheel drive system 386
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Rear view monitor system 390
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Cruise control 394
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Rear height control air suspension 397
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Electronic modulated suspension 404
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Active traction control system 405
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Vehicle stability control system 407
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Downhill assist control system 410
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Hill-start assist control system 413
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Brake system 415
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Tire pressure warning system 419
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Brake pad wear limit indicators 428
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Limited-slip differential 429
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STARTING AND DRIVING
397
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 HIº (high), Nº
(normal) and LOº (low) modes with the height select
switch.
(a) Vehicle height modes
Nº (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. HIº
(high) mode: The vehicle height is about 40 mm (1.6 in.)
higher at the rear than the Nº 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 HIº mode, the Nº mode is automatically
selected.
CAUTION
The HIº mode should be used for severe off-road
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.
LOº (low) mode: The vehicle height is about 20 mm (0.8 in.)
lower at the rear than the Nº 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
400
NOTICE
If the vehicle height is changed frequently when thevehicle is heavily loaded, the compressor mayoverheat causing the vehicle height adjustmentoperation to stop.
Before you lower the vehicle height with the heightselect switch, check under the vehicle to make surenothing to dam age 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 vehicle equipped with
the rear height control air suspension becomes
slightly higher than the normal vehicle height. Takesufficient care where the overhead height isrestricted.
Do not select the LOº mode in the bumpy roads. Ifthe underbody of the vehicle touches the ruggedroad surface, the vehicle may be damaged.

STARTING AND DRIVING
401
(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 OFFº
switch. The height control OFFº 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 OFFº 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 OFFº switch, if the vehicle speed
exceeds 30 km/h (19 mph), the rear height control air
suspension automatically selects the Nº mode.
CAUTION
If you drive through deep water over about 700 mm (28
in.) in depth, put the vehicle height in the HIº mode with
the height select switch and then turn off the rear height
control air suspension by pushing the HEIGHT
CONTROL OFFº switch.

STARTING AND DRIVING
402
NOTICE
When jacking up or installing tire chains, be sure toturn off the rear height control air suspension withthe HEIGHT CONTROL OFFº switch and stop theengine. Otherwise, the vehicle height may changebecause of the automatic leveling function resultingin accident.
If your vehicle must be towed, put the vehicle heightin the Nº mode and turn off the rear height control airsuspension. Otherwise, the vehicle height may
change because of the automatic leveling functionresulting in accident.
If your vehicle gets ditched, turn off the rear heightcontrol air suspension with the HEIGHT CONTROLOFFº switch. Otherwise, the vehicle height maychange because of the automatic leveling functionresulting in accident.

STARTING AND DRIVING
403
(e) Height control indicator lights

1Height control indicator lights
2Height control OFFº 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 Nº mode to
HIº:
1. The Nº mode indicator light goes off and the HIº mode
indicator light blinks.
2. After the vehicle height control reaches the HIº mode, the
HIº 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 OFFº 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 OFFº switch,
the rear height control air suspension is turned off. The height
control OFFº 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 OFFº indicator light does not come on
when the ignition switch is turned on.
 The height control OFFº indicator light blinks.

STARTING AND DRIVING
404
(f) Parking and stopping tips
If you immediately stop the engine to park the vehicle after
off-road driving, the vehicle height is lowered slightly as the
vehicle becomes cool. When parking, make sure there is
nothing that will be in contact with the underbody of the vehicle.
When you start the engine, the vehicle returns to the previous
height.
If you park the vehicle for a long time, the vehicle height may
be gradually lowered. When parking for a long time, make sure
there is nothing that will be in contact with the underbody of the
vehicle. When you start the engine, the vehicle returns to the
previous height.
If you stop the engine, the vehicle height may change in
accordance with the change in the temperature. When you
start the engine, the vehicle returns to the previous height.
(g) Rear height control failure warning
If there is a problem somewhere in the rear height control air
suspension, the Nº mode is automatically selected. If this
occurs, the height control OFFº indicator light blinks and the
vehicle height control cannot be activated until the malfunction
is corrected. If this is the case, bring your vehicle to your Lexus
dealer as soon as possible and have it checked.
ELECTRONIC MODULATED SUSPENSION
This electronic modulated suspension adjusts the
damping effect on the shock absorbers with the control
switch. Select one of the 4 modes which is suited to the
driving conditions with the control switch to provide good
riding comfort and stability.
1For driving on a bumpy road
2For ordinary driving such as in the city traffic
3For moderate high speed driving
4For sporty type driving such as on winding mountain
roads and high speed driving
5Soft
6Firm

DRIVING TIPS
442
TRAILER TOWING
(vehicles with kinetic dynamic suspension system)
Lexus does not recommend towing a trailer with your vehicle.
It is not designed for a towing hitch receiver.
TRAILER TOWING
(vehicles without kinetic dynamic suspension system)
Your vehicle is designed primarily as a passenger-and-load
carrying vehicle. Towing a trailer will have an adverse ef fect on
handling, performance, braking, durability and driving
economy (fuel consumption, etc.). Your safety and satisfaction
depend on the proper use of correct equipment and cautious
driving habits. For your safety and the safety of others, you
must not overload your vehicle or trailer. Lexus warranties do
not apply to damage or malfunction caused by towing a trailer
for commercial purposes. Ask your local Lexus dealer for
further details before towing.
CAUTION
When disconnecting a trailer, put the vehicle height in
the LOº (low) mode and push the HEIGHT CONTROL
OFFº switch to turn off the rear height control air
suspension. Otherwise, the vehicle height may be
changed in the automatic leveling function, resulting in
accident. For details see Rear height control air
suspensionº on page 397.

DRIVING TIPS
451
Trailer lights
Your vehicle is equipped with a wire harness stored in the rear
end underbody. Use either of them to connect and operate the
trailer lights. However, the trailer lights must comply with
federal, state/provincial and local regulations. See your local
recreational vehicle dealer or rental agency for the correct type
of wiring and relays for your trailer. Check for correct operation
of the turn signals and stop lights each time you hitch up. Direct
splicing may damage your vehicle's electrical system and
cause a malfunction of your lights.
Break-in schedule
Lexus recommends that you do not tow a trailer with a new
vehicle or a vehicle with any new power train component
(engine, transmission, differential, wheel bearing, etc.) for the
first 800 km (500 miles) of driving.
Maintenance
 If you tow a trailer, your vehicle will require more frequent
maintenance due to the additional load. For this
information, please refer to the scheduled maintenance
information in the Owner's Manual Supplement/Scheduled
Maintenanceº.
 Retighten all fixing bolts of the towing ball and bracket after
approximately 1000 km (600 miles) of trailer driving.
Connecting a trailer
Stop your vehicle and a trailer in line and perform the following:
1. Put the rear height control air suspension in the LOº (low)
mode. Turn the ignition switch off or push the HEIGHT
CONTROL OFFº switch to turn off the rear height control air
suspension.
2. Connect a trailer.
3. Turn the ignition switch on or push the HEIGHT CONTROL
OFFº switch to turn on the rear height control air suspension.
Select the Nº (normal) mode with the height select switch.
Disconnecting a trailer
Stop your vehicle and a trailer in line and perform the following:
1. Put the rear height control air suspension in the LOº (low)
mode. (Make sure the vehicle height is in the LOº (low) mode
by pushing the height select switch on the  º side.)
2. Turn the ignition switch off or push the HEIGHT CONTROL
OFFº switch to turn off the rear height control air suspension.
3. Set the supporting leg of a trailer on the ground and raise the
hitch by 100 mm (4 in.).
4. Turn the ignition switch on or push the HEIGHT CONTROL
OFFº switch to turn on the rear height control air suspension.
5. Wait for about 20 seconds until the rear vehicle height is
lowered by the automatic leveling function.

DRIVING TIPS
4526. Make sure the hitch is disconnected. If not, raise the hitch
higher and repeat steps 2 through 5.
7. Move the vehicle forward in the LOº (low) mode where the
hitch does not touch anything in the Nº (normal) mode.
8. Put the rear height control air suspension in the Nº (normal)
mode.
Pre-towing safety check

Check that your vehicle remains level when a loaded or
unloaded trailer is hitched. Do not drive if the vehicle has an
abnormal nose-up or nose-down condition, and check for
improper tongue load, overload, worn suspension or other
possible causes.
 Make sure the trailer cargo is securely loaded so that it
cannot shift.
 Check that your rear view mirrors conform to any federal,
state/provincial or local regulations. If they do not, install
required rear view mirrors appropriate for towing purposes.
Trailer towing tips
When towing a trailer, your vehicle will handle differently
than when not towing. The three main causes of
vehicle-trailer accidents are driver error, excessive speed
and improper trailer loading. Keep these in mind when
towing:
 Before starting out, check the operation of the lights and all
vehicle-trailer connections. After driving a short distance,
stop and recheck the lights and connections. Practice
turning, stopping and backing with a trailer in an area away
from traffic until you learn the feel.
 Backing with a trailer is difficult and requires practice. Grip
the bottom of the steering wheel and move your hand to the
left to move the trailer to the left. Move your hand to the right
to move the trailer to the right. (This procedure is generally
opposite to that when backing without a trailer.) Also, just
turn the steering wheel a little at a time, avoiding sharp or
prolonged turning. Have someone guide you when backing
to reduce the risk of an accident.
 Because stopping distance may be increased,
vehicle-to-vehicle distance should be increased when
towing a trailer. For each 16 km/h (10 mph) of speed, allow
at least one vehicle and trailer length between you and the
vehicle ahead. Avoid sudden braking as you may skid,
resulting in jackknifing and loss of control. This is especially
true on wet or slippery surfaces.