LEXUS RX400H 2008 Owners Manual

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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.
■Traction Control
Maintains drive power and prevents the front wheels (2WD models) or all
wheels (AWD models) from spinning wh en starting the vehicle or acceler-
ating on slippery roads.
■ EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel.
■VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, VSC, traction control
and EPS systems.
Maintains vehicle stability when swerving on slippery road surfaces by
controlling the brakes, engine output, and the movement of the front
wheels.

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When the VSC/traction control are operatingIf the vehicle is in danger of slip-
ping, or if the front wheels (2WD
models) or all wheels (AWD mod-
els) spin, the slip indicator light
flashes to indicate that the VSC/
traction control have been
engaged.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
■Sounds and vibrations caused by the ABS, brake assist, VSC and traction control
●A sound may be heard from the engine compartment when the hybrid system 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.
■Reduced effectiveness of EPS
The effectiveness of EPS is reduced to prevent the system from overheating when
there is frequent steering input over an extended period of time. The steering wheel
may feel heavy as a result. Should this occur, refrain from excessive steering input or
stop the vehicle and turn the hybrid system OFF. The system should return to nor-
mal within 10 minutes.

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CAUTION
Any of the following conditions may result in an accident which could cause death or
serious injury:
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded.
●The vehicle hydroplanes while driving at high speed on the wet or slick road.
■Stopping distance when the ABS is operating will exceed that of normal condi-
tions
The ABS is not designed to shorten the vehicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you in the following situations.
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or roads with uneven roads
■Traction control may not operate effectively when
Directional control and power may not be achievable while driving on slippery road
surfaces, even if the traction control system is operating.
Do not drive the vehicle in conditions where stability and power may be lost.

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CAUTION
■When the slip indicator flashes and a warning buzzer sounds
This situation occurs immediately while VSC is activated. Always drive carefully.
Reckless driving may cause an accident. Exercise particular care when the indica-
tor light flashes and a buzzer sounds.
■Replacing tires
Make sure that all tires are of the same size, brand, tread pattern and total load
capacity. In addition, make sure that the tires are inflated to the recommended tire
pressure level.
The ABS and VSC systems will not function correctly if different tires are fitted on
the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels.
■Handling of tires and suspension
Using tires with any kind of problem or modifying the suspension will affect the
VDIM, and may cause the system to malfunction.

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2-5. Driving information
Utility vehicle precautions
Utility vehicle feature● Specific design characteristics give it a higher center of gravity than
ordinary passenger cars. This vehicle design feature causes this type of
vehicle to be more likely to rollover. And, utility vehicles have a signifi-
cantly higher rollover rate than other types of vehicles.
● It is not designed for cornering at the same speeds as ordinary passen-
ger cars any more than low-slung sports cars designed to perform sat-
isfactorily under off-road conditions. Therefore, sharp turns at
excessive speeds may cause rollover.
This vehicle belongs to the utility vehicle class, which has higher ground
clearance and narrower tread in relation to the height of its center of grav-
ity.

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CAUTION
■Utility vehicle precautions
Always observe the following precautions to minimize the risk of serious personal
injury or damage to your vehicle:
●In a rollover crash, an unbelted person is significantly more likely to die than a
person wearing a seat belt. Therefore, the driver and all passengers should fasten
their seat belts whenever the vehicle is moving.
●Avoid sharp turns or abrupt maneuvers, if at all possible.
Failure to operate this vehicle correctly may result in loss of control or vehicle roll-
over causing death or serious injury.
●Loading cargo on the roof luggage carrier will make the center of the vehicle
gravity higher. Avoid high speeds, sudden starts, sharp turns, sudden braking or
abrupt maneuvers, otherwise it may result in loss of control or vehicle rollover
due to failure to operate this vehicle correctly.
●Always slow down in gusty crosswinds. Because of its profile and higher center of
gravity, your vehicle is more sensitive to side winds than an ordinary passenger
car. Slowing down will allow you to have better control.
●Do not drive horizontally across steep slopes. Driving straight up or straight down
is preferred. Your vehicle (or any similar off-road vehicle) can tip over sideways
much more easily than forward or backward.

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Off-road drivingYour vehicle is not designed to be driven off-road. However, in the event
that off-road driving cannot be avoided, please observe the following
precautions to help avoid the areas prohibited to vehicles.
● Drive your vehicle only in areas where off-road vehicles are permitted
to travel.
● Respect private property. Get owner’s permission before entering pri-
vate property.
● Do not enter areas that are closed. Honor gates, barriers and signs
that restrict travel.
● Stay on established roads. When conditions are wet, driving tech-
niques should be changed or travel delayed to prevent damage to
roads.
● Avoid driving on very steep, slippery roads and other surfaces, such as
sand, where the tires are liable to lose traction. Your vehicle may not
perform as well as conventional AWD on-road vehicles on these sur-
faces.
■Additional information for off-road driving
For owners in U.S. mainland, Hawaii and Puerto Rico:
To obtain additional information pertaining to driving your vehicle off-road, consult
the following organizations.
●State and Local Parks and Recreation Departments
●State Motor Vehicle Bureau
●Recreational Vehicle Clubs
●U.S. Forest Service and Bureau of Land Management

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CAUTION
■Off-road driving precautions
Always observe the following precautions to minimize the risk of serious personal
injury or damage to your vehicle:
●Drive carefully when off the road. Do not take unnecessary risks by driving in
dangerous places.
●Do not grip the steering wheel spokes when driving off-road. A bad bump could
jerk the wheel and injure your hands. Keep both hands and especially your
thumbs on the outside of the rim.
●Always check your brakes for effectiveness immediately after driving in sand,
mud, water or snow.
●After driving through tall grass, mud, rock, sand, rivers, etc., check that there is no
grass, bush, paper, rags, stone, sand, etc. adhering or trapped on the underbody.
Clear off any such matter from the underbody. If the vehicle is used with these
materials trapped or adhering to the underbody, a breakdown or fire could occur.
●When driving off-road or in rugged terrain, do not drive at excessive speeds,
jump, make sharp turns, strike objects, etc. This may cause loss of control or vehi-
cle rollover causing death or serious injury. You are also risking expensive dam-
age to your vehicle’s suspension and chassis.
NOTICE
■To prevent the water damage
Take all necessary safety measures to ensure that water damage to the hybrid bat-
tery, hybrid system or other components does not occur.
●Water entering the engine compartment may cause severe damage to the hybrid
system. Water entering the interior may cause the hybrid battery stowed under
the rear seats to short circuit.
●Water entering the hybrid transaxle will cause deterioration in transmission qual-
ity. The malfunction indicator may come on, and the vehicle may not be drivable.
●Water can wash the grease from wheel bearings, causing rusting and premature
failure, and may also enter the transaxle case, reducing the gear oil’s lubricating
qualities.

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NOTICE
■When you drive through water
If driving through water, such as when crossing shallow streams, first check the
depth of the water and the bottom of the river bed for firmness. Drive slowly and
avoid deep water.
■Inspection after off-road driving
●Sand and mud that has accumulated in brake drums and around brake discs may
affect braking efficiency and may damage brake system components.
●Always perform a maintenance inspection after each day of off-road driving that
has taken you through rough terrain, sand, mud, or water. For scheduled mainte-
nance information, refer to the “Warranty and Services Guide/Owner’s Manual
Supplement/Scheduled Maintenance”.

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Cargo and luggage
Capacity and distributionCargo capacity depends on the total weight of the occupants.
(Cargo capacity) = (Total load cap acity) — (Total weight of occupants)
Steps for Determining Correct Load Limit 
(1) Locate the statement “The combined weight of occupants and cargo should never exceed XXX kg or XXX lbs.” on your vehicle’s placard.
(2) Determine the combined weight of the driver and passengers that will be riding in your vehicle.
(3)Subtract the combined weight of the driver and passengers from XXX kg or XXX lbs.
(4) The resulting figure equals the available amount of cargo and luggage load capacity.
For example, if the “XXX” amount equals 1400 lbs. and there will be
five 150 lb passengers in your vehicle, the amount of available cargo
and luggage load capacity is 650 lbs. (1400 − 750 (5 × 150) = 650
lbs.)
(5)Determine the combined weight of luggage and cargo being loaded on the vehicle. That weight may not safely exceed the available cargo
and luggage load capacity calculated in Step 4.
Take notice of the following information about storage precautions, cargo
capacity and load.
●Stow cargo and luggage in the luggage compartment whenever
possible. Be sure all items are secured in place.
● Be careful to keep the vehicle level. Placing the weight as far for-
ward as possible helps maintain vehicle balance.
● For better fuel economy, do not carry unnecessary weight.