engine coolant Lexus GS450h 2008 Do-it-yourself maintenance / LEXUS 2008 GS450H OWNER'S MANUAL (OM30A96U)

148
GS_HV_U
December 12, 2007 3:50 pm
2-2. Instrument cluster
Gauges and meters
The units used on the speedometer may differ depending on the target
region.

The following gauges, meters and display illuminate when the
“POWER” switch is in ON mode.
Power meter
Displays the instantaneous output from the hybrid system is approximate
kilowatts.
Speedometer
Displays the vehicle speed.
Fuel gauge
Displays the quantity of fuel remaining in the tank.
Engine coolant temperature gauge
Displays the engine coolant temperature.
Multi-information display
 P. 1 5 5

151
2-2. Instrument cluster
2
When driving
GS_HV_U
December 12, 2007 3:50 pm
NOTICE
■To prevent damage to the engine and its components
The engine may be overheating if the engine coolant temperature gauge is in the
red zone (“H”). In this case, immediately stop the vehicle in a safe place. Check the
engine after it has cooled completely. ( P. 5 3 8 )
■To activate the light sensitivity function properly
Do not affix a sticker or window tint to the rear window glass, or put an object
behind the rear seat.

215
2-5. Driving information
2
When driving
GS_HV_U
December 12, 2007 3:50 pm
Winter driving tips
Carry out the necessary preparations and inspections before driving the
vehicle in winter. Always drive the vehicle in a manner appropriate to the
prevailing weather conditions.
■ Pre-winter preparations
●Use fluids that are appropria te to the prevailing outside tempera-
tures.
• Engine oil
• Engine/power control unit coolant
• Washer fluid
● Have a service technician inspect th e level and specific gravity of
battery electrolyte.
● 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 same si ze and brand, and that chains match
the size of the tires.
■ Before driving the vehicle
Perform the following according to the driving conditions.
● Do not try to forcibly open a w indow or move a wiper that is fro-
zen. Pour warm water over the frozen area to melt the ice. Wipe
away the water immediately to prevent it from freezing.
● To ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents in
front of the windshield.
● Remove any ice that has accumul ated on the vehicle chassis.
● Periodically check for and remove any excess ice or snow that
may have accumulated in the wheel well or on the brakes.

410
4-2. Maintenance
GS_HV_U
December 12, 2007 3:50 pm
General maintenance
Engine compartment
Luggage compartment
ItemsCheck points
Brake fluid• At the correct level? (P. 4 2 9 )
Engine/power control unit coolant• At the correct level? ( P. 4 2 7 )
Engine oil• At the correct level? ( P. 4 2 2 )
Exhaust system• No fumes or strange sounds?
Radiator/condenser/hoses• Not blocked with foreign matter? 
( P. 4 2 8 )
Wa s h e r f l u i d• At the correct level? ( P. 4 3 4 )
ItemsCheck points
12 volt battery• Maintenance-free ( P. 4 3 0 )
Listed below are the general maintenance items that should be performed
at the intervals specified in the “Warranty and Services Guide/Owner’s
Manual Supplement”. It is recommend ed that any problem you notice
should be brought to the attention of your Lexus dealer or qualified service
shop for advice.

414
GS_HV_U
December 27, 2007 1:38 pm
4-3. Do-it-yourself maintenance
Do-it-yourself service precautions
If you perform maintenance yourself, be sure to follow the correct proce-
dure given in these sections.
ItemsPa r t s a n d t o o l s
12 volt battery condition (P. 4 3 0)
•Grease
• Conventional wrench
(for terminal clamp bolts)
Brake fluid level ( P. 4 2 9 )
• FMVSS No.116 DOT 3 or SAE
J1703 brake fluid
•Rag or paper towel
• Funnel (used only for adding brake fluid)
Engine/power control unit coolant
level ( P. 4 2 7 )
• “Toyota Super Long Life Coolant”
or similar high quality ethylene gly-
col 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 Coolant”
is pre-mixed with 55% coolant and
45% deionized water.
• Funnel (used only for adding cool- ant)

416
4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
CAUTION
The engine compartment contains many mechanisms and fluids that may move sud-
denly, become hot, or become electrically energized. To avoid death or serious injury,
observe the following precautions.
■When working on the engine compartment
●Keep hands, clothing, and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, power control unit, radiator, exhaust manifold,
etc. right after driving as they may be hot. Oil and other fluids may also be hot.
●Do not leave anything that may burn easily , such as paper or rags, in the engine
compartment.
●Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes are flam-
mable.
■When working near the electric cooling fan or radiator grille
Be sure the “POWER” switch is OFF. 
With the “POWER” switch in ON mode, the electric cooling fan may automatically
start to run if the air conditioning is on and/or the coolant temperature is high. 
(  P. 4 2 8 )
■Safety glasses
Wear safety glasses to prevent flying or fall ing material, fluid spray, etc. from getting
in the eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine wear due to
dirt in the air. Also a backfire could cause a fire in the engine compartment.

420
4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
Engine compartment
■12 volt battery
P. 4 3 0
Engine oil level dipstick 
( P. 422)
Engine oil filler cap 
( P. 423)
Brake fluid reservoir 
( P. 4 2 9 )
Fuse box ( P. 4 5 6 )Washer fluid tank 
( P. 4 3 4 )
Gasoline engine/power 
control unit coolant 
reservoir ( P. 4 2 7 )
Electric cooling fans
Condenser ( P. 4 2 8 )
Radiator ( P. 4 2 8 )

488
5-1. Essential information
GS_HV_U
December 12, 2007 3:50 pm
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■ Visible symptoms
●Fluid leaks under the vehicle 
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temper ature gauge needle continually points
higher than normal
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the hybrid system
■ Operational symptoms
●Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, sp ongy feeling, pedal almost touches
the floor

538
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
If your vehicle overheats
If your hybrid system overheats:
Stop the vehicle in a safe place and turn off the air conditioning
system.
Check to see if steam is coming out from under the hood.
If you see steam: 
Stop the hybrid system and carefully lift the hood.
If you do not see steam: Leave the hybrid system running and carefully lift the hood.
Remove the engine compartment cover. ( P. 421)
Check to see if the cooling fan is operating.
If the fan is operating: 
Wait until the engine coolant temperature gauge begins to
fall and then stop the hybrid system.
If the fan is not operating: 
Stop the hybrid system immed iately and call your local
Lexus dealer.
After the hybrid system has
cooled down sufficiently, check
the coolant level and inspect the
radiator core (radiator) for any
leaks.STEP1
STEP2
STEP3
STEP4
STEP5

5
When trouble arises
539
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
■Overheating
In the following situations, your vehicle may be overheating.
●The engine coolant temperature gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
●The message “HYBRID SYSTEM OVERHEAT” is displayed on the multi-infor-
mation display.
CAUTION
■To prevent an accident or injury when in specting under the hood of your vehicle
●Keep hands and clothing away from the fan and engine drive belt while the hybrid
system is running.
●Do not loosen the radiator cap while the hybrid system and radiator are hot. 
Serious injury, such as burns, may resu lt from hot coolant and steam released
under pressure.
Add coolant if necessary.
Water can be used in an emer-
gency measure if coolant is
unavailable. ( P. 5 4 8 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP6