air suspension Lexus GX470 2003 How To Use This Manual / LEXUS 2003 GX470 (OM60979U) User Guide

DRIVING TIPS
347
TRAILER TOWING
Your vehicle is designed primarily as a passenger−and−load
carrying vehicle. T owing a trailer will have an adverse ef fect on
handling, performance, braking, durability and driving
economy (fuel consumption, etc.). Y our 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 “LO” (low) mode and push the “HEIGHT CONTROL
OFF” 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
suspension” on page 315.
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
CAUTION
 The maximum gross trailer weight (trailer weight plus
cargo weight) must never exceed 2268 kg (5000 lb.)
for vehicle with equipped. If towing a trailer and
cargo weighing over 907 kg (2000 lb.), it is necessary
to use a sway control device with sufficient capacity.
The combination of the gross trailer weight added to
the total weight of the vehicle, occupants and vehicle
cargo must never exceed a total of 4764 kg (10500 lb.).
Exceeding the maximum weight of the trailer, the
vehicle, or the vehicle and trailer combination, can
cause an accident resulting in serious personal
injuries.

DRIVING TIPS
353
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 Maintenance”.
 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 “LO” (low)
mode. Turn the ignition switch off or push the “HEIGHT
CONTROL OFF” 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
OFF” switch to turn on the rear height control air suspension.
Select the “N” (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 “LO” (low)
mode. (Make sure the vehicle height is in the “LO” (low) mode
by pushing the height select switch on the “
” side.)
2. Turn the ignition switch off or push the “HEIGHT CONTROL
OFF” 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
OFF” 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 “LO” (low) mode where the
hitch does not touch anything in the “N” (normal) mode.
8. Put the rear height control air suspension in the “N” (normal)
mode.

IN CASE OF AN EMERGENCY
364B: 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 − well away from the
traffic. A void 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. Firmly set the parking brake and put the transmission in “P”.
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.
 Do not put any part of your body under a vehicle
supported by a jack. Personal injury may occur.
 Do not start or run the engine while your vehicle is
supported by the jack.
 Stop the vehicle on a level firm ground, firmly set the
parking brake and put the transmission in “P”. Block
the wheel diagonally opposite to the one being
changed if necessary.

IN CASE OF AN EMERGENCY
365
Make sure to set the jack properly in the jack point.
Raising the vehicle with jack improperly positioned
will damage the vehicle or may allow the vehicle to fall
off the jack and cause personal injury.
 Never get under the vehicle when the vehicle is
supported by the jack alone.
 Use the jack only for lifting your vehicle during wheel
changing.
 Do not raise the vehicle with someone in the vehicle.
 When raising the vehicle, do not place any objects on
top of or underneath the jack.
 Raise the vehicle only high enough to remove and
change the tire.
NOTICE
Do not continue driving with a deflated tire. Driving
even a short distance can damage a tire and wheel
beyond repair.
 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.
40PY040
 1 Jack

2 Spare tire

3 Tool tray
1. Get the tool, jack and spare tire.
To remove the tool tray, turn the knob counterclockwise and
open the cover, then pull the tray out.

IN CASE OF AN EMERGENCY
376
IF YOUR VEHICLE NEEDS TO BETOWED
If towing is necessary, we recommend you to have it done
by your Lexus dealer or a commercial tow truck service.
In consultation with them, have your vehicle towed using
either (a) or (b).
(a) Towing with a wheel lift type truck
(b) Using a flat bed truck
(c) Never tow with a sling type truck
Only when you cannot receive a towing service from a
Lexus dealer or commercial tow truck service, tow your
vehicle carefully in accordance with the instructions
given in “(d) Emergency towing” on page 380.
Proper equipment will help ensure that your vehicle is not
damaged while being towed. Commercial operators are
generally aware of the state/provincial and local laws
pertaining to towing.
Your vehicle can be damaged if it is towed incorrectly. Although
most operators know the correct procedure, it is possible to
make a mistake. To avoid damage to your vehicle, make sure
the following precautions are observed. If necessary, show
this page to the tow truck driver. TOWING PRECAUTIONS:
Use a safety chain system for all towing, and abide by the
state/provincial and local laws. The wheels and axle on the
ground must be in good condition. If they are damaged, use
a towing dolly.
CAUTION
When
your vehicle is towed, put the vehicle height in the
“N” (normal) mode and push the “HEIGHT CONTROL
OFF” 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
suspension” on page 315.

MAINTENANCE
399
Brake fluid level
Make sure the brake fluid level is correct. See page 430 for
additional information.
Engine oil level
Check the level on the dipstick with the engine turned off and
the vehicle parked on a level spot. See page 419 for
additional
information.
Power steering fluid level
Check the level through the reservoir. The level should be in
the “HOT” or “COLD” range depending on the fluid
temperature. See page 431 for additional information.
Exhaust system
If you notice any change in the sound of the exhaust or smell
exhaust fumes, have the cause located and corrected
immediately. (See “Engine exhaust caution” on page 298.)
DOES YOUR VEHICLE NEED REPAIRING?
Be on the alert for changes in performance and sounds, and
visual tip −offs that indicate service is needed. Some important
clues are:
 Engine missing, stumbling, or pinging
 Appreciable loss of power
 Strange engine noises
 A fluid leak under the vehicle (However, water dripping from
the air conditioning after use is normal.)
 Change in exhaust sound (This may indicate a dangerous
carbon monoxide leak. Drive with the windows open and
have the exhaust system checked immediately.)
 Flat−looking tires, excessive tire squeal when cornering,
uneven tire wear
 Vehicle pulls to one side when driving straight on a level
road
 Strange noises related to suspension movement
 Loss of brake effectiveness, spongy feeling brake pedal,
pedal almost touches floors, vehicle pulls to one side when
braking
 Engine coolant temperature continually higher than normal

CHASSIS
439
Chain installation
Install the chains on the rear tires as tightly as possible.
Do not use tire chains on the front tires. Retighten chains
after driving 0.5 1.0 km (1/4 1/2 mile).
When installing chains on your tires, carefully follow the
instructions of the chain manufacturer.
CAUTION
Do not exceed 50 km/h (30 mph) or the chain
manufacturer’s recommended speed limit,
whichever is lower.
 Drive carefully avoiding bumps, holes, and sharp
turns, which may cause the vehicle to bounce.
 Avoid sharp turns or lockedwheel braking, as use of
chains may adversely affect vehicle handling.
 When driving with chains installed, be sure to drive
carefully. Slow down before entering the curves to
avoid losing control of the vehicle. Otherwise an
accident may occur.
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.
REPLACING WHEELS
When to replace your wheels
If you have wheel damage such as bending, cracks or
heavy corrosion, the wheel should be replaced.
If you fail to replace damaged wheels, the tire may slip off the
wheel or cause loss of handling control.
Replacement with used wheels is not recommended as they
may have been subjected to rough treatment or high mileage
and could fail without warning. Also, bent wheels which have
been straightened may have hidden structural damage and
therefore should not be used. Never use an inner tube in a
leaking wheel which is designed for a tubeless tire.
Wheel selection
When replacing wheels, care should be taken to ensure
that they are equivalent to those removed in load capacity,
diameter, rim width, and offset.
Correct replacement wheels are available at your Lexus
dealer.
A wheel of a different size or type may adversely affect
handling, wheel and bearing life, brake cooling,
speedometer/odometer calibration, stopping ability, headlight
aim, bumper height, vehicle ground clearance, and tire or snow
chain clearance to the body and chassis.

ELECTRICAL COMPONENTS
445
No.FUSEAMPERECIRCUIT
13 MIR
HEATER10Outside rear view mirror defog-
ger
14 STOP10
Stop lights, high m ounted
stoplight, shift lock control
system, vehicle skid control
system, electronic m odulated
suspension, rear height control
air suspension, multiport fuel
injection system/sequential
multiport fuel injection system
15 AC115V
INV15Power outlet (115 VAC)
16 FR FOG15Front fog lights
17 OBD7.5On −board diagnosis system
18 HEAD
(LO RH)10Right− hand headlight (low beam)
19 HEAD
(LO LH)10Left− hand headlight (low beam)
20 HEAD
(HI RH)10Right− hand headlight (high
beam)
21 HEAD
(HI LH)10Left− hand headlight (high beam)
22 EFI NO.210Multiport fuel injection system/
sequential multiport fuel injection
system
23 HEATER
NO.27.5Air conditioning system
24 DEFOG30Rear window defogger
No.FUSEAMPERECIRCUIT
25 AIRSUSNO.210Rear height control air suspen-
sion
26 SEAT
HEATER20Seat heaters
27 DOME10
Ignition switch light, interior
lights, personal lights, foot
lights, running board lights,
door courtesy lights, inside
door handle lights,
multi− information display
28 RADIO
NO.120Car audio system, navigation
system
29 ECUB10
Multiplex communication
system, vehicle skid control
system, wireless remote
control system, inside rear
view mirror, air conditioning
system, electronic modulated
suspension, driving position
memory system, power
windows, moon roof
30 ECUB NO.210Theft deterrent system
31 ABS
MTR40
Anti −lock brake system,
vehicle skid control system,
active traction control system,
brake assist system
32 AM230Starting system, all components
in “IGN”, “SRS”, “GAUGE” and
“ST2” fuses