traction control LEXUS RX400H 2008 Owners Manual

RX400h_U
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CAUTION
■General precautions while driving
Driving under the influence: Never drive your vehicle when under the influence of
alcohol or drugs that have impaired your ability to operate your vehicle. Alcohol
and certain drugs delay reaction time, impair judgment and reduce coordination,
which could lead to an accident that will hurt or kill you, your occupants or others.
Defensive driving: Always drive defensively. Anticipate mistakes that other drivers
or pedestrians might make and be ready to avoid accidents.
Driver distraction: Always give your full attention to driving. Anything that distracts
the driver, such as adjusting controls, talking on a cellular phone or reading can
result in a collision with resulting death or serious injury to you, your occupants or
others.
■General precaution regarding children’s safety
Never leave children unattended in the vehicle, and never allow children to have or
use the key.
Children may be able to start the vehicle or shift the vehicle into neutral. There is
also a danger that children may injure themselves by playing with the cigarette
lighter, the windows, the moon roof, or other features of the vehicle. In addition, heat
build-up or extremely cold temperatures inside the vehicle can be fatal to children.
■Dispose of the hybrid battery (traction battery)
If your vehicle is disposed of without the hybrid battery having been removed, there
is a danger of serious electric shock if high voltage parts, cables and their connec-
tors are touched. In the event of that your vehicle must be disposed of, the hybrid
battery must be disposed of your Lexus dealer or a qualified service shop. If the
hybrid battery is not disposed of properly, they may cause electric shock that can
result in death or serious injury.

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1-1. Hybrid system
1
Before driving
RX400h_U
High voltage components*: With AWD models only
Take care when handling the hybrid system, as it contains a high voltage
system (about 650V at maximum) as well as parts that become
extremely hot when the hybrid system is operating. Obey the caution
labels attached to the vehicle. Air conditioning compressor
High voltage cables (orange
color)
Power control unit
Hybrid battery (traction bat-
tery)
Service plug
DC/DC converter
Rear electric motor (traction
motor)*
Front electric motor (traction
motor)
Caution label

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2-1. Driving procedures
2
When driving
RX400h_U
CAUTION
■When driving the vehicle
●Do not drive if you are unfamiliar with the location of the brake and accelerator
pedals to avoid depressing the wrong pedal.
• Accidentally depressing the accelerator pedal instead of the brake pedal willresult in sudden acceleration that may lead to an accident that could result in
death or serious injury.
• When backing up, you may twist your body around, leading to a difficulty in operating the pedals. Make sure to operate the pedals properly.
• Make sure to keep a correct driving posture even when moving the vehicle
only slightly, allowing you to depress the brake and accelerator pedals prop-
erly.
• Depress the brake pedal using your right foot. Depressing the brake pedal using your left foot may delay response in an emergency, resulting in an acci-
dent.
●The driver should pay attention to pedestrians when the vehicle is powered only
by the electric motor (traction motor). Because there is no engine noise, the
pedestrians may misjudge the vehicle’s movement.
●Do not drive the vehicle over or stop the vehicle near flammable materials.
●Do not let the vehicle roll backwards while th e shift lever is in a driving position, or
roll forward while the shift lever is in R.
Doing so may cause the hybrid system to stall or lead to poor brake and steering
performance, resulting in an accident or damage to the vehicle.
●If the smell of exhaust is noticed inside the vehicle, open the windows and check
that the back door is closed. Large amounts of exhaust in the vehicle can cause
driver drowsiness and an accident, resulting in death or a serious health hazard.
Have the vehicle inspected by your Lexus dealer immediately.
●Do not under any circumstances shift the shift lever to P, R or N while the vehicle
is moving.
Doing so can cause significant damage to the transmission system and may result
in a loss of vehicle control.
●Do not shift the shift lever to N while the vehicle is moving.
Doing so may cause the engine brake to not operate properly and lead to an
accident.

169
2-4. Using other driving systems
2
When driving
RX400h_U
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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2-4. Using other driving systems
RX400h_U
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.

171
2-4. Using other driving systems
2
When driving
RX400h_U
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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5-2. Steps to take in an emergency
RX400h_U
(Flashing and then
continuously on)
Indicates a malfunction in the tire pressure warning
system. (→P. 3 3 2 )
(Flashing)
Malfunction in the traction control system or VSC
system.
(Flashing)
Indicates a malfunction in the dynamic laser cruise
control system.
Wa r n i n g m e s s a g eDetails

5
When trouble arises
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5-2. Steps to take in an emergency
RX400h_U
Have the vehicle inspected by your Lexus dealer immediately.
Failing to investigate the cause of the following warning may lead to the
system operating abnormally and possibly cause an accident. Have the
vehicle inspected by your Lexus dealer immediately.
Wa r n i n g m e s s a g eDetails
Indicates a malfunction in the traction control, VSC
systems.

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6-1. Specifications
6
Vehicle specifications
RX400h_U
Uniform tire quality gradingThis information has been prepared in accordance with regulations
issued by the National Highway Traffic Safety Administration of the
U.S.A. Department of Transportation.
It provides the purchasers and/or prospective purchasers of Lexus vehi-
cles with information on uniform tire quality grading.
Your Lexus dealer will help answer any questions you may have as you read
this information.
■ DOT quality grades
All passenger vehicle tires must conform to Federal Safety Require-
ments in addition to these grades. Quality grades can be found where
applicable on the tire sidewall between tread shoulder and maximum
section width.
For example: Treadwear 200 Traction AA Temperature A
■Treadwear
The treadwear grade is a comparative rating based on the wear rate of
the tire when tested under controlled conditions on a specified gov-
ernment test course.
For example, a tire graded 150 would wear one and a half (1 - 1 /2) times as
well on the government course as a tire graded 100.
The relative performance of tires depends upon the actual conditions of
their use, however, and may depart sign ificantly from the norm due to varia-
tions in driving habits, service practices and differences in road characteris-
tics and climate.

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6-1. Specifications
RX400h_U■
Traction AA, A, B, C
The traction grades, from highest to lowest, are AA, A, B and C, and
they represent the tire's ability to stop on wet pavement as measured
under controlled conditions on specified government test surfaces of
asphalt and concrete.
A tire marked C may have poor traction performance.
Warning: The traction grade assigned to this tire is based on braking
(straight ahead) traction tests and does not include cornering (turning) trac-
tion.
■ Temperature A, B, C
The temperature grades are A (the highest), B, and C, representing
the tire's resistance to the generation of heat and its ability to dissipate
heat when tested under controlled conditions on a specified indoor
laboratory test wheel.
Sustained high temperature can cause the material of the tire to degenerate
and reduce tire life, and excessive temperature can lead to sudden tire fail-
ure.
The grade C corresponds to a level of performance which all passenger car
tires must meet under the Federal Motor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels of performance on the laboratory
test wheel than the minimum required by law.
Warning: The temperature grades for this tire are established for a tire that
is properly inflated and not overloaded.
Excessive speed, underinflation, or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.