
285
4-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■Before using LKA system
Do not rely solely upon the LKA system. Th e LKA system does not automatically drive
the vehicle or reduce the amount of attention that must be paid to the area in front of
the vehicle. The driver must always assume full responsibility for driving safely by pay-
ing careful attention to the surrounding conditions and operating the steering wheel to
correct the path of the vehicle. Also, the driver must take adequate breaks when
fatigued, such as from driving for a long period of time.
Failure to perform appropriate driving operat ions and pay careful attention may lead to
an accident, resulting in death or serious injury.
■To avoid operating LKA system by mistake
When not using the LKA system, use the LKA switch to turn the system off.
■Situations unsuitable for LKA system
Do not use the LKA system in the following situations.
The system may not operate properly and le ad to an accident, resulting in death or
serious injury.
●A spare tire, tire chains, etc. are equipped.
●When the tires have been excessively worn, or when the tire inflation pressure is low.
●Tires which differ by structure, manufacturer, brand or tread pattern are used.
●Objects or patterns that could be mistaken for white (yellow) lines are present on the
side of the road (guardrails, cu rbs, reflective poles, etc.).
●Vehicle is driven on a snow-covered road.
●White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.
●Asphalt repair marks, white (yellow) line ma rks, etc. are present due to road repair.
●Vehicle is driven in a temporary lane or restricted lane due to construction work.
●Vehicle is driven on a road surface which is slippery due to rainy weather, fallen snow,
freezing, etc.
●Vehicle is driven in traffic lanes other than on highways and freeways.
●Vehicle is driven in a construction zone.
●Vehicle is towing a trailer or another vehicle. (vehicles with towing package)
■Preventing LKA system malfunctions and operations performed by mistake
●Do not modify the headlights or place stickers, etc. on the surface of the lights.
●Do not modify the suspension etc. If the suspension etc. needs to be replaced, con-
tact any authorized Lexus retailer or Le xus authorized repairer, or any reliable
repairer.
●Do not install or place anything on the hood or grille. Also, do not install a grille guard
(bull bars, kangaroo bar, etc.).
●If your windshield needs repairs, contac t any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.

2904-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
●The vehicle is driven on a road which t ilts left or right, or a winding road.
●The vehicle is driven on an unpaved or rough road.
●The vehicle is driven around a sharp curve.
●The traffic lane is excessively narrow or wide.
●The vehicle is extremely tilted due to carrying heavy luggage or having improper tire
pressure.
●The distance to the preceding vehicle is extremely short.
●The vehicle is moving up and down a large amount due to road conditions during driv-
ing (poor roads or road seams).
●The headlight lenses are dirty and emit a faint amount of light at night, or the beam axis
has deviated.
●The vehicle is struck by a crosswind.
●The vehicle has just changed lanes or crossed an intersection.
●Snow tires, etc. are equipped.
■Warning message
Warning messages are used to indicate a syst em malfunction or to inform the driver of
the need for caution while driving. ( P. 466)
■Customization
The following settings can be changed.
For how to change settings, refer to P. 561.
FunctionSetting details
Lane departure alert functionAdjust alert sensitivity
Adjust alert type
Steering assist functionTurn steering wheel assistance on and off
Vehicle sway warning functionTurn function on and off
Adjust alert sensitivity
Lane centering functionTurn function on and off

3304-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■When the VSC is activated
The slip indicator light flashes. Always drive carefully. Reckless driving may cause an
accident. Exercise particular care when the indicator light flashes.
■When the TRC/VSC systems are turned off
Be especially careful and drive at a speed appropriate to the road conditions. As these
are the systems to help ensure vehicle stability and driving force, do not turn the TRC/
VSC systems off unless necessary.
■Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and total load
capacity. In addition, make sure that the tires are inflated to the recommended tire infla-
tion pressure level.
The ABS, TRC and VSC systems will not function correctly if different tires are installed
on the vehicle.
Contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer for further information when replacing tires or wheels.
■Handling of tires and the suspension
Using tires with any kind of problem or modi fying the suspension will affect the driving
assist systems, and may cause a system to malfunction.

3324-6. Driving tips
GS450h_300h_OM_OM30F92E_(EE)
◆Delays
Repeated acceleration and deceleration, as well as long waits at traffic lights,
will lead to bad fuel economy. Check traffic reports before leaving and avoid
delays as much as possible. When driving in a traffic jam, gently release the
brake pedal to allow the vehicle to move forward slightly while avoiding over-
use of the accelerator pedal. Doing so can help control excessive gasoline
consumption.
◆Highway driving
Control and maintain the vehicle at a constant speed. Before stopping at a toll
booth or similar, allow plenty of time to release the accelerator and gently
apply the brakes. A greater amount of electrical energy can be regenerated
when slowing down.
◆Air conditioning
Use the air conditioning only when necessary. Doing so can help reduce
excessive gasoline consumption.
In summer: When the ambient temperature is high, use the recirculated air
mode. Doing so will help to reduce the burden on the air conditioning system
and reduce fuel consumption as well.
In winter: Because the gasoline engine will not automatically cut out until it
and the interior of the vehicle are warm, it will consume fuel. Also, fuel con-
sumption can be improved by avoiding overuse of the heater.
◆Checking tire inflation pressure
Make sure to check the tire inflation pressure frequently. Improper tire infla-
tion pressure can cause poor fuel economy.
Also, as snow tires can cause large amounts of friction, their use on dry roads
can lead to poor fuel economy. Use ti res that are appropriate for the season.

3384-6. Driving tips
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■Driving with snow tires
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in a loss of vehicle control and cause death or serious injury.
●Use tires of the specified size.
●Maintain the recommended level of air pressure.
●Do not drive at speeds in excess of the speed limit or the speed limit specified for the
snow tires being used.
●Use snow tires on all, not just some wheels.
■Driving with tire chains (vehicles with front and rear tires of the same size except for
the vehicles with LDH and 19 inch tires)
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in the vehicle being unable to be driven safely, and may
cause death or serious injury.
●Do not drive in excess of the speed limit sp ecified for the tire chains being used, or
50 km/h (30 mph), whichever is lower.
●Avoid driving on bumpy road surfaces or over potholes.
●Avoid sudden acceleration, abrupt steerin g, sudden braking and shifting operations
that cause sudden engine braking.
●Slow down sufficiently before entering a curve to ensure that vehicle control is main-
tained.
●Do not use LKA (Lane-Keeping Assist) system. (if equipped)
NOTICE
■Repairing or replacing snow tires
Request repairs or replacement of snow ti res from Lexus dealers or legitimate tire
retailers.
This is because the removal and attachment of snow tires affects the operation of the
tire pressure warning va lves and transmitters.
■Fitting tire chains (vehicles with front and rear tires of the same size except for the
vehicles with LDH and 19 inch tires)
The tire pressure warning valves and transmitters may not function correctly when tire
chains are fitted.
■When standing the windshield wipers up
Raise the wipers in line with the windshield. ( P. 337)
Failure to do so may result in damage to the wipers and/or the hood.

389
6Maintenance and care
GS450h_300h_OM_OM30F92E_(EE) 6-1. Maintenance and care
Cleaning and protecting the vehicle exterior ................390
Cleaning and protecting the vehicle interior.................. 394
6-2. Maintenance Maintenance requirements ............................ 397
6-3. Do-it-yourself maintenance Do-it-yourself service precautions................................ 399
Hood ................................................ 401
Positioning a floor jack ............ 402
Engine compartment ...............403
12-volt battery ...............................412
Tires ...................................................416
Tire inflation pressure .............. 429
Wheels ............................................ 431
Air conditioning filter ............... 433
Electronic key battery.............. 435
Checking and replacing fuses.............................................. 437
Light bulbs..................................... 442

4166-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
Tires
Check if the treadwear indicators are show ing on the tires. Also check the tires
for uneven wear, such as excessive wear on one side of the tread.
Check the spare tire condition and pressure if not rotated.
New tread
Worn tread
Treadwear indicator
The location of treadwear indicators is shown by the “TWI” or “ ” mark, etc., molded
into the sidewall of each tire.
Replace the tires if the treadwear indicators are showing on a tire.
Replace or rotate tires in accordance with maintenance schedules and trea d-
wear.
Checking tires
1
2
3

417
6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE) Rotate the tires in the order shown.
To equalize tire wear and help extend tire life, Lexus recommends that tire rota-
tion is carried out approximately every 10000 km (6000 miles).
Do not fail to initialize the tire pressure warning system after tire rotation
. (vehicle
with the tire pressure warning system)
Your vehicle is equipped with a tire pressu re warning system that uses tire pres-
sure warning valves and transmitters to detect low tire inflation pressure bef ore
serious problems arise.
Vehicles without the tire inflation pressure display function
If the tire pressure drops below a predetermined level, the driver is warned by a
warning light. ( P. 463)
Vehicles with the tire inflation pressure display function
● If the tire pressure drops below a predetermined level, the driver is warned b y
the multi-information display and a warning light. ( P. 460, 466)
● The tire pressure detected by the
tire pressure warning system can be
displayed on the multi-information
display. ( P. 111)
The illustration used is intended as an
example, and may differ from the image
that is actually displayed on the multi-
information display.
Tire rotation
Vehicles with front and rear tires of
the same sizeVehicles with front and rear tires of
differing sizes
FrontFront
Tire pressure warning system (if equipped)