coolant Lexus GS450h 2007 Hybrid system / LEXUS 2007 GS450H THROUGH JUNE 2006 PROD. (OM30727U) User Guide

5
When trouble arises
475
5-2. Steps to take in an emergency
If your vehicle overheats
■Electric motor (traction motor) and inverter
If the message “HYBRID SYSTEM OVERHEAT” is displayed on the
multi-information display.
■ Ga
soline engine
If the needle of the engine co olant temper
ature gauge enters the
red zone, the gasoline engine has probably overheated.
Observe the following steps: Stop the vehicle in a safe place and turn of
f the automatic 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. 362 )
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 s
ystem.
If the fan is not operating: 
Stop the hybrid system immed iately and call y
our local
Lexus dealer.
After the hybrid system has
cooled do
wn sufficiently, check
the coolant level and inspect the
radiator core (radiator) for any
leaks.
STEP1
STEP2
STEP3
STEP4
STEP5

476
5-2. Steps to take in an emergency
■Overheating
In the following situations, your vehicle may be overheating.
●The message “HYBRID SYSTEM OVERHEAT” is displayed on the multi-infor-
mation display.
●The engine coolant temperatur e gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
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 required.
Water can be used in an emer -
gency measure if coolant is
una
vailable. ( P. 4 8 4 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos -
sible.
STEP6

5
When trouble arises
477
5-2. Steps to take in an emergency
NOTICE
■When adding coolant
Wait until the hybrid system has cooled down before adding coolant.
When adding coolant, do so slowly. Adding cool coolant to a hot hybrid system too
quickly can cause damage to the hybrid system.

484
6-1. Specifications
Cooling system
Ignition system
Capacity
Gasoline engine
Inverter9.8 qt. (9.3 L, 8.1 lmp.qt.)
3.0 qt. (2.9 L, 2.5 lmp.qt.)
Coolant type
Use either of the following:• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based non-sili- cate, non-amine, non-nitrite, and non-borate cool-
ant with long-life organic acid technology
Do not use plain water alone.
Spark plug
Make DENSO 
NGK
GapFK20HBR11 
ILFR6D11T 
0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust gap when tuning engine.

497
6-1. Specifications
6
Vehicle specifications
Warning: The temperature grades for this tire are established for a tire that
is properly inflated and not overloaded.
Excessive speed, underinflation, or excess iv
e loading, either separately or in
combination, can cause heat build up and possible tire failure.
Glossary of tire terminology
Tire related termMeaning
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of automatic transmis-
sion, power steering, power brakes, power windows,
power seats, radio and heater, to the extent that these
items are available as factory-installed equipment
(whether installed or not)
Cold tire inflation pres-
sureTire pressure when the vehicle has been parked for
three hours or more, or has not been driven more
than 1 mile or 1.5 km under that condition
Curb weight
The weight of a motor vehicle with standard equip-
ment, including the maximum capacity of fuel, oil and
coolant, and if so equipped, air conditioning and
additional weight optional engine
Maximum inflation pres-
sureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
Maximum loaded vehicle
weight
The sum of: 
(a) Curb weight 
(b) Accessory weight 
(c) Vehicle capacity weight 
(d) Production options weight
Normal occupant weight150 lb. (68 kg) times the number of occupants speci-
fied in the second column of Table 1
* that follows

512
Alphabetical index
Emergency, in case ofIf a warning light turns on .............. 430
If a warning message is 
displayed ............................................ 436
If the hybrid system will not 
start........................................................ 466
If the shift lever cannot be 
shifted from P ................................... 467
If the 12 volt battery is 
discharged ......................................... 471
If you have a flat tire ............ 455, 456
If you lose your keys......................... 468
If you think something is 
wrong ....................................................427
If your vehicle becomes stuck..... 478
If your vehicle needs to be 
towed ................................................... 420
If your vehicle overheats ................ 475
When the electronic key battery 
is discharged .................................... 469
Energy monitor............................................ 6
Engine Compartment ....................................... 361
Hood........................................................ 358
How to start the hybrid system
.....101
If the hybrid system will not 
start........................................................ 466
Overheating......................................... 475
Power switch .......................................... 101
Engine compartment cover ............. 362
Engine coolant temperature 
gauge.........................................................110
Engine/inverter coolant Capacity ................................................. 484
Checking ............................................... 368
Preparing and checking 
before winter ...................................... 174 Engine oil
Capacity ................................................ 483
Checking............................................... 363
Preparing and checking  before winter...................................... 174
Engine oil maintenance data ........... 366
EPS (Electric Power Steering) ......... 162
Event data recorder ............................ 428
First-aid kit storage belt ..................... 332
Floor mats .................................................. 331
Fluid Brake ....................................................... 370
Washer.................................................... 374
Fog lights Switch ........................................................ 123
Wattage ................................................. 488
Foot light .................................................. 308
Front passenger's seat
belt 
reminder light ..................................... 433
Front seats Adjustment ............................................... 34
Driving position memory .................. 36
Front turn signal lights Wattage ................................................. 488
Fuel Capacity ................................................ 482
Fuel gauge ................................................ 110
Gas station information ................. 520
Information ........................................... 489
Refueling ................................................... 58
Messages .............................................. 450
Fuel filler door ........................................... 58
Fuses .......................................................... 395
F

518
What to do if...
What to do if...
A tire puncturesP. 4 5 5 /
456If you have a flat tire
The hybrid system does not start
P. 6 2Hybrid vehicle immobilizer system
P. 4 6 6If the hybrid system will not start
P. 4 7 1If the 12 volt battery is discharged
The shift lever cannot be 
moved outP. 4 6 7If the shift lever cannot be shifted 
from “P”
The engine coolant temperature
gauge enters the red zone
Steam can be seen coming 
from under the hood
P. 4 7 5If your vehicle overheats
The key is lostP. 4 6 8If you lose your keys
The battery runs outP. 4 7 1If the 12 volt battery is discharged
The doors cannot be lockedP. 2 6Doors
The horn begins to soundP. 6 4Alarm
The vehicle is stuck in mud or
sandP. 4 7 8If the vehicle becomes stuck