air suspension Lexus GX470 2005 Engine / LEXUS 2005 GX470 (OM60B11U) User Guide

SECTION 3 ± 1
392
STARTING AND DRIVING
Starting and driving
Three±way catalytic converters393
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Engine exhaust caution 396
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Before starting the engine 398
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Ignition switch 398
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Parking brake 400
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How to start the engine 401
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Automatic transmission 403
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Four±wheel drive system 411
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Rear view monitor system 415
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Cruise control 419
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Rear height control air suspension 422
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Electronic modulated suspension 429
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Active traction control system 430
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Vehicle stability control system 433
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Downhill assist control system 436
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Hill±start assist control 439
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Brake system 442
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Tire pressure warning system 446
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Brake pad wear limit indicators 456
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Limited±slip differential 457
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STARTING AND DRIVING
422
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 ªHIº (high), ªNº
(normal) and ªLOº (low) modes with the height select
switch.
(a) Vehicle height modes
ªNº (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. ªHIº
(high) mode: The vehicle height is about 40 mm (1.6 in.)
higher at the rear than the ªNº 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 ªHIº mode, the ªNº mode is automaticall\
y
selected.
CAUTION
The ªHIº 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.
ªLOº (low) mode: The vehicle height is about 20 mm (0.8 in.)
lower at the rear than the ªNº 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
425
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 ªLOº mode in the bumpy roads. Ifthe underbody of the vehicle touches the ruggedroad surface, the vehicle may be damaged.

STARTING AND DRIVING
426
(d) Turning off the rear height control airsuspension
To turn off the rear height control air suspension with the
vehicle stopped, push the ªHEIGHT CONTROL OFFº
switch. The height control ªOFFº 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 ªOFFº 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 ªHEIGHT CONTROL OFFº switch, if the vehicle speed
exceeds 30 km/h (19 mph), the rear height control air
suspension automatically selects the ªNº mode.
CAUTION
If you drive through deep water over about 700 mm (28
in.) in depth, put the vehicle height in the ªHIº mode with
the height select switch and then turn off the rear height
control air suspension by pushing the ªHEIGHT
CONTROL OFFº switch.

STARTING AND DRIVING
427
NOTICE
When jacking up or installing tire chains, be sure toturn off the rear height control air suspension withthe ªHEIGHT 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 ªNº 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 ªHEIGHT CONTROLOFFº switch. Otherwise, the vehicle height maychange because of the automatic leveling functionresulting in accident.

STARTING AND DRIVING
428
(e) Height control indicator lights

1Height control indicator lights
2Height control ªOFFº 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 ªNº mode to
ªHIº:
1. The ªNº mode indicator light goes off and the ªHIº mode
indicator light blinks.
2. After the vehicle height control reaches the ªHIº mode, the
ªHIº 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 ªOFFº indicator light: When the ignition
switch is t
urned 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 ªHEIGHT CONTROL OFFº switch,
the rear height control air suspension is turned off. The height
control ªOFFº 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 ªOFFº indicator light does not come on
when the ignition switch is turned on.
 The height control ªOFFº indicator light blinks.

STARTING AND DRIVING
429
(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 ªNº mode is automatically selected. If this
occurs, the height control ªOFFº 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
470
TRAILER TOWING
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 ªLOº (low) mode and push the ªHEIGHT 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 ªRear height control air
suspensionº on page 422.
Weight limits
Before towing, make sure the total trailer weight, gross
vehicle weight, gross axle weight and trailer tongue load
are all within the limits.
The total trailer weight and tongue load can be measured with
platform scales found at a highway weighing station, building
supply company, trucking company, junk yard, etc.

Certification label

DRIVING TIPS
479
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 ªLOº (low)
mode. Turn the ignition switch off or push the ªHEIGHT
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 ªHEIGHT CONTROL
OFFº switch to turn on the rear height control air suspension.
Select the ªNº (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 ªLOº (low)
mode. (Make sure the vehicle height is in the ªLOº (low) mode
by pushing the height select switch on the ª º side.)
2. Turn the ignition switch off or push the ªHEIGHT 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 ªHEIGHT 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.
6. 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 ªLOº (low) mode where the
hitch does not touch anything in the ªNº (normal) mode.
8. Put the rear height control air suspension in the ªNº (normal)
mode.
Pre±towing safety check

Check that your vehicle remains level when a loaded or
unloaded tra iler 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.

IN CASE OF AN EMERGENCY
497
B: If no steam is coming from your engine:
Leave the engine running and turn off the air conditioning.
Check the following.

Is the cooling fan operating?
 Is the coolant in the acceptable range?
 Is the engine drive belt O.K.?
CAUTION
When the engine is running, keep hands and clothing
away from the moving fan and engine drive belt.
 Do not attempt to remove the radiator cap when the
engine and radiator are hot. Serious injury could
result from scalding hot fluid and steam blown out
under pressure.
If the cooling fan is not operating or the coolant is not in the
acceptable range, turn off the engine and call your Lexus
dealer.
If both conditions are O.K., after the engine coolant
temperature has cooled to normal, continue driving your
vehicle.
If the engine coolant temperature does not cool down, or your
vehicle overheats again, have it checked as soon as possible
by your Lexus dealer.
IF YOU HAVE A FLAT TIRE
1. Reduce your speed gradually, keeping a straight
line. Move cautiously off the road to a safe place
Ð well away from the traffic. Avoid stopping on the
center divider of a highway. Park on a level spot with
firm ground.
2. Stop the engine and turn on your emergency
flashers.
3. F i r m l y s e t t h e p a r k i n g b r a k e a n d p u t t h e
transmission in ªPº.
4. Have everyone get out of the vehicle on the side
away from traffic.
5. Read the following instructions thoroughly.
CAUTION
When jacking, be sure to observe the following
to reduce the possibility of personal injury:
Turn off the active height control suspension
by pushing the active height control switch.
 Follow jacking instructions.