258
GS450h_U (OM30D01U)
4-5. Using the driving support systems
●When driving on winding roads or roads that are uneven
●When driving on rough or unpaved roads
■When changing the tires
Depending on the tires used, sufficient performance may not be maintainable.
■Warning messages for LKA
Warning messages are used to indicate a system malfunction or to inform the driver
of the need for caution while driving. (→P. 7 2 4 , 7 3 5 )
CAUTION
■Before using the LKA system
Do not rely solely on the LKA system. The LKA system does not drive the vehicle
automatically, nor does it reduce the amount of care you need to take. As such, the
driver must always assume full responsibility for understanding his/her surround-
ings, for operating the steering wheel to correct the driving line, and for driving
safely.
Inappropriate or negligent driving could lead to an accident.
■To avoid operating the LKA by mistake
Switch the LKA off using the “LKA” switch when not in use.
■Situations unsuitable for LKA
Do not use LKA in any of the following situations.
Otherwise, the system may not function correctly and could result in an accident.
●When driving with snow tires, tire chains, a spare tire, or similar equipment
●When the tires have been excessively worn, or when the tire inflation pressure is
low.
●When there are objects or structures along the roadside that might be misinter-
preted as lane markers (such as guardrails, curb, reflector posts, etc.)
●When driving on snowy roads
●When pavement lane markers are difficult to see due to rain, snow, fog, etc.
●When there are visible lines on the pavement from road repairs, or if the remains
of old lane markers are still visible on the road
●When driving on slippery roads, such as those covered with rain, ice or snow
●When driving in a lane other than the driving or passing lanes on a freeway or
highway
●When driving on a road with lane closures due to maintenance, or when driving
in a temporary lane
●When emergency towing
GS450h_U.book Page 258 Monday, January 23, 2012 10:20 AM
GS450h_U (OM30D01U)
2834-5. Using the driving support systems
4
Driving
CAUTION
■When using the rear view monitor system
When backing up, be sure to check visually behind and all around the vehicle
before proceeding.
Observe the following precautions to avoid an accident that could result in death
or serious injuries.
●The rear view monitor system is a supplemental device intended to assist the
driver when backing up. Never depend on the rear view monitor system entirely
when backing up. Always make sure your intended path is clear.
Use caution, just as you would when backing up any vehicle.
●Never back up while looking only at the screen.
The image shown on the screen may differ from the actual state, and you could
collide with another vehicle or obstacles if backing up looking only at the screen,
possibly causing an accident. When backing up, be sure to check in front of and
behind the vehicle, both directly and with mirrors.
●Be sure to back up slowly, depressing the brake pedal to control vehicle speed.
●The instructions given are only guidelines.
When and how much to turn the steering wheel will vary according to traffic con-
ditions, road surface conditions, vehicle condition, etc. when parking. It is neces-
sary to be fully aware of this before using the rear view monitor system.
●When parking, be sure to check that the parking space will accommodate your
vehicle before maneuvering into it.
●Do not use system in the following cases:
• On icy or slick road surfaces, or in snow
• When using tire chains or the compact spare tire
• When the trunk lid is not closed completely
• On roads that are not flat or straight, such as curves or slopes.
●In low temperatures, the screen may darken or the image may become faint. The
image could distort when the vehicle is moving, or you may become unable to
see the image on the screen. Be sure to check direct visually and with mirror all
around the vehicle before proceeding.
●If the tire sizes are changed, the position of the fixation guide lines displayed on
the screen may change.
●The camera uses a special lens. The distances between objects and pedestrians
that appear in the image displayed on the screen will differ from the actual dis-
tances. (→P. 277)
GS450h_U.book Page 283 Monday, January 23, 2012 10:20 AM
294
GS450h_U (OM30D01U)
4-5. Using the driving support systems
CAUTION
■The ABS does not operate effectively when
●Tires with inadequate gripping ability are used (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 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 uneven surfaces
■TRAC may not operate effectively when
Directional control and power may not be achievable while driving on slippery
road surfaces, even if the TRAC system is operating.
Do not drive the vehicle in conditions where stability and power may be lost.
■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 vehicle stability and driving force, do not turn the
TRAC/VSC systems off unless necessary.
GS450h_U.book Page 294 Monday, January 23, 2012 10:20 AM
319
GS450h_U (OM30D01U)4-6. Driving tips
4
Driving
Winter driving tips
●Use fluids that are appropriate to the prevailing outside temperatures.
• Engine oil
• Engine/power control unit coolant
•Washer fluid
●Have a service technician inspect the condition of the 12-volt battery.
●Have the vehicle fitted with four snow tires or purchase a set of tire
chains for the rear tires.
Ensure that all tires are the specified size and brand, and that chains match the
size of the tires.
Carry out the necessary preparatio ns and inspections before driving
the vehicle in winter. Always drive the vehicle in a manner appropriate
to the prevailing weather conditions.
Preparation for winter
GS450h_U.book Page 319 Monday, January 23, 2012 10:20 AM
322
GS450h_U (OM30D01U)
4-6. Driving tips
If heavy snow or icy condition is expected, shift the rest position manually.
Grip the hook section of the wiper arm firmly when shifting the wiper
position.
■To rest position
Raise the wiper in line with the
windshield.
You can stand the wipers up for the
rest position.
★ : More than 3.9 in. (10 cm)
■To retract position
Lower the wipers by pressing on
the upper part of the hook sec-
tion.
■Tire chain installation
Observe the following precautions when installing and removing chains:
●Install and remove tire chains in a safe location.
●Install tire chains on the rear tires. Do not install tire chains on the front tires.
●Install tire chains on rear tires as tightly as possible. Retighten chains after driving
1/4 1/2 mile (0.5 1.0 km).
●Install tire chains following the instructions provided with the tire chains.
Shifting the windshield wiper position
GS450h_U.book Page 322 Monday, January 23, 2012 10:20 AM
GS450h_U (OM30D01U)
3234-6. Driving tips
4
Driving
CAUTION
■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 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.
●Do not use LKA (Lane-Keeping Assist) system.
■Driving with tire chains
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 tire 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, as well as sudden braking and shift-
ing operation to engine braking.
●Slow down sufficiently before entering a curve to ensure that vehicle control is
maintained.
●Do not use LKA (Lane-Keeping Assist) system.
GS450h_U.book Page 323 Monday, January 23, 2012 10:20 AM
324
GS450h_U (OM30D01U)
4-6. Driving tips
NOTICE
■Repairing or replacing snow tires
Request repairs or replacement of snow tires 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 valves and transmitters.
■Fitting tire chains
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. 3 2 2 )
Failure to do so may result in damage to the wipers and/or the hood.
GS450h_U.book Page 324 Monday, January 23, 2012 10:20 AM
656
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
■Low profile tires (except 225/50R17 tires)
Generally, low profile tires will wear more rapidly and tire grip performance will be
reduced on snowy and/or icy roads when compared to standard tires. Be sure to use
snow tires or tire chains on snowy and/or icy roads and drive carefully at a speed
appropriate for road and weather conditions.
■Maximum load of tire
Check that the maximum load of the replacement tire is greater than 1 /2 of the
Gross Axle Weight Ratings (GAWR) of either the front axle or the rear axle, which-
ever is greater.
■Tire types
●Summer tires
Summer tires are high-speed performance tires best suited to highway driving
under dry conditions. Since summer tires do not have the same traction perfor-
mance as snow tires, summer tires are inadequate for driving on snow-covered or
icy roads. For driving on snow-covered roads or icy roads, the use of snow tires is
recommended. When installing snow tires, be sure to replace all four tires.
●All season tires
All season tires are designed to provide better traction in snow and to be ade-
quate for driving in most winter conditions as well as for use year-round. All season
tires, however, do not have adequate traction performance compared with snow
tires in heavy or loose snow. Also, all season tires fall short in acceleration and han-
dling performance compared with summer tires in highway driving.
●Snow tires
For driving on snow-covered roads or icy roads, we recommend using snow tires.
If you need snow tires, select tires of the same size, construction and load capacity
as the originally installed tires. Since your vehicle has radial tires as original equip-
ment, make sure your snow tires also have radial construction. Do not install stud-
ded tires without first checking local regulations for possible restrictions. Snow
tires should be installed on all wheels. (→P. 3 1 9 )
For the GAWR, see the Certification Label.
For the maximum load of the tire, see the load
limit at maximum cold tire inflation pressure
mentioned on the sidewall of the tire.
(
→ P. 7 9 5 )
GS450h_U.book Page 656 Monday, January 23, 2012 10:20 AM