
GS450h_OM_OM30G62U_(U)
2414-5. Using the driving support systems
4
Driving
■Hands off steering wheel alert
When the system determines that the driver has removed the hands from the steering
wheel while the steering assist function or lane centering function is operating, a warning
message is displayed on th e multi-information display.
If the driver continues to keep the hands off of the steering wheel, a buzzer sounds, a
warning message is displayed. This alert also operates in the same way when the driver
continuously operates the steering wheel only a small amount. However, depending on
the road conditions, etc., the function may not cancel.
■White (yellow) lines are only on one side of road
The LKA system will not operate for the side on which white (yellow) lines could not be
recognized.
■Conditions in which functions may not operate properly
In the following situations, the camera sensor may not detect white (yellow) lines and var-
ious functions may not operate normally.
●There are shadows on the road that run parallel with, or cover, the white (yellow) lines.
●The vehicle is driven in an ar ea without white (yellow) lines, such as in front of a tollgate
or checkpoint, or at an intersection, etc.
●The white (yellow) lines are cracked, “Botts ’ dots”, “Raised pavement marker” or stones
are present.
●The white (yellow) lines cannot be seen or are difficult to see due to sand, etc.
●The vehicle is driven on a road surface that is wet due to rain, puddles, etc.
●The traffic lines are yellow (which may be more difficult to recognize than lines that are
white).
●The white (yellow) lines cross over a curb, etc.
●The vehicle is driven on a bright surface, such as concrete.
●The vehicle is driven on a surface that is bright due to reflected light, etc.
●The vehicle is driven in an area where the brightness changes suddenly, such as at the
entrances and exits of tunnels, etc.
●Light from the headlights of an oncoming vehicle, the sun, etc. enters the camera.
●The vehicle is driven where the road diverges, merges, etc.
●The vehicle is driven on a slope.
●The vehicle is driven on a road which tilts 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 carry ing 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 am ount due to road conditions during driv-
ing (poor roads or road seams).

GS450h_OM_OM30G62U_(U)
2734-5. Using the driving support systems
4
Driving
WARNING
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded. (such as excessively
worn tires on a snow covered road).
●The vehicle hydroplanes while driving at high speed on wet or slick roads.
■Stopping distance when the ABS is operating may exceed that of normal conditions
The ABS is not designed to shorten the vehi cle’s stopping distance. Always maintain a
safe distance from the vehicle in front of you, especially in the following situations:
●When driving on dirt, grav el or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or uneven surfaces
■TRAC may not operate effectively when
Directional control and power may not be achievable wh ile driving on slippery road
surfaces, even if the TRAC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
■Hill-start assist control does not operate effectively when
●Do not overly rely on the hill-start assist control. The hill-start assist control may not
operate effectively on steep inclines and roads covered with ice.
●Unlike the parking brake, hill-start assist co ntrol is not intended to hold the vehicle
stationary for an exte nded period of time. Do not atte mpt to use hill-start assist con-
trol to hold the vehicle on an incline, as doing so may lead to an accident.
■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 TRAC/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 stab ility and driving force, do not turn the
TRAC/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 tire s are inflated to the recommended tire infla-
tion pressure level.
The ABS, TRAC and VSC systems will not function correctly if different tires are
installed on the vehicle.
Contact your Lexus dealer for further in formation 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.

GS450h_OM_OM30G62U_(U)
2754-6. Driving tips
4
Driving
◆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 drivin g 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 co nstant speed. Before stopping at a toll
booth or similar, allow plenty of ti me 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 av oiding overuse of the heater.
◆Checking tire inflation pressure
Make sure to check the tire inflation pr essure frequently. Improper tire infla-
tion pressure can cause poor fuel economy.
Also, as snow tires can cause large amou nts of friction, their use on dry roads
can lead to poor fuel economy. Use tires that are appropriate for the season.
◆Luggage
Carrying heavy luggage will lead to poor fuel economy. Avoid carrying
unnecessary luggage. Installing a large roof rack will also cause poor fuel
economy.
◆Warming up before driving
Since the gasoline engine starts up an d cuts out automatically when cold,
warming up the engine is unnecessary. Moreover, frequently driving short dis-
tances will cause the engine to repeated ly warm up, which can lead to excess
fuel consumption.

280
GS450h_OM_OM30G62U_(U)
4-6. Driving tips
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 vehi cle control and cause death or serious injury.
●Use tires of the specified size.
●Maintain the recommended level of air pressure.
●Do not drive in excess of 75 mph (120 km/h ), regardless of the type of 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 specified for the ti re chains being used, or 30
mph (50 km/h), whichever is lower.
●Avoid driving on bumpy road surfaces or over potholes.
●Avoid sudden acceleration, abrupt steering, sudden braking and shifting operations
that cause sudden engine braking.
●Slow down sufficiently before entering a cu rve 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 an d 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 valv es 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. 279)
Failure to do so may result in dama ge to the wipers and/or the hood.

335
GS450h_OM_OM30G62U_(U)
6Maintenance and care
6-1. Maintenance and care Cleaning and protecting the vehicle exterior ................ 336
Cleaning and protecting the vehicle interior..................340
6-2. Maintenance Maintenance requirements ... 343
General maintenance.............. 345
Emission inspection and maintenance (I/M)
programs ....................................348
6-3. Do-it-yourself maintenance Do-it-yourself service precautions................................ 349
Hood ................................................ 351
Positioning a floor jack ............ 352
Engine compartment ...............353
12-volt battery ............................. 362
Tires ................................................. 365
Tire inflation pressure............... 375
Wheels ........................................... 378
Air conditioning filter .............. 380
Electronic key battery ..............382
Checking and replacing fuses ..............................................384
Headlight aim (vehicles with single-beam headlights).......389
Light bulbs...................................... 391

GS450h_OM_OM30G62U_(U)
3476-2. Maintenance
6
Maintenance and care
Vehicle exterior
ItemsCheck points
Doors/trunk• Do the doors/trunk operate smoothly?
Engine hood• Does the engine hood lock system work prop-erly?
Fluid leaks•There should not be an y signs of fluid leakage
after the vehicle has been parked.
Tires
• Is the tire inflation pressure correct?
• The tires should not be damaged or excessively
worn.
• Have the tires been rotated according to the
maintenance schedule?
• The wheel nuts should not be loose.
Windshield wipers
•The wiper blades should not show any signs of
cracking, splitting, wear , contamination or defor-
mation.
• The wiper blades should clear the windshield without streaking or skipping.
WARNING
■If the hybrid system is operating
Turn the hybrid system off and ensure that there is adequate ventilation before per-
forming maintenance checks.

349
GS450h_OM_OM30G62U_(U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Do-it-yourself service precautions
*: Vehicles with sing le-beam headlights
If you perform maintenance by yourself, be sure to follow the correct proce-
dure as given in these sections.
ItemsParts and tools
12-volt battery con-
dition (→P. 362)•Grease
• Conventional wrench (for terminal clamp bolts)
Brake fluid level
(→ P. 360)
• FMVSS No.116 DOT 3 or SAE J1703 brake fluid
• Rag or paper towel
• Funnel (used only for adding brake fluid)
Engine/power con-
trol unit coolant level
(→ P. 358)
•“Toyota Super Long Life Coolant” or a similar high quality
ethylene glycol-based non-silicate, non-amine, non-nitrite
and non-borate coolant with long-life hybrid organic acid
technology
For the U.S.A.:
“Toyota Super Long Life Coolant” is pre-mixed with 50%
coolant and 50% deionized water.
For Canada:
“Toyota Super Long Life Cool ant” is pre-mixed with 55%
coolant and 45% deionized water.
• Funnel (used only for adding coolant)
Engine oil level
( → P. 355)
• “Toyota Genuine Motor Oil” or equivalent
• Rag or paper towel
• Funnel (used only for adding engine oil)
Fuses ( →P. 384)• Fuse with same amperage rating as original
Headlight aim*
( → P. 389)• Phillips-head screwdriver
Light bulbs
(→ P. 391)
• Bulb with same number and wattage rating as original
• Phillips-head screwdriver•Flathead sc rewdriver
•Wrench
Radiator and con-
denser (→P. 359)⎯
Tire inflation pres-
sure (→P. 375)• Tire pressure gauge• Compressed air source
Washer fluid
(→ P. 361)• Water or washer fluid containing antifreeze (for winter use)
• Funnel (used only for adding water or washer fluid)

365
GS450h_OM_OM30G62U_(U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Tires
Check if the treadwear indicators are showing 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 indicato rs is shown by a “TWI” or “Δ” 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 tread-
wear.
Checking tires
1
2
3