cooling Lexus GS450h 2010 Using The Audio System / LEXUS 2010 GS450H OWNERS MANUAL (OM30C81U)

27
1-1. Hybrid system
1
Before driving
GS_HV_U (OM30C81U)
February 12, 2010 8:52 am
■After the 12 volt battery has discharged or has been changed or removed
The gasoline engine may not stop even if the vehicle is running on the hybrid battery
(traction battery). If this continues for a few days, contact your Lexus dealer.
■Sounds and vibrations specific to a hybrid vehicle
There may be no engine sounds or vibration even though the vehicle is able to
move. Always put the shift lever in “P” when parked.
The following sounds or vibrations may occur when the hybrid system is operating,
and are not a malfunction.
●Motor sounds may be heard from the engine compartment.
●Sounds may be heard from the hybrid battery (traction battery) behind the rear
seat when the hybrid system starts or stops.
●Sounds from the hybrid system may be heard when the trunk lid is open.
●Sounds may be heard from the transmission when the hybrid system starts or
stops.
●Engine sounds may be heard when accelerating sharply.
●Sounds may be heard from the regenerative brake when you press the brake
pedal.
●Vibration may be felt when the gasoline engine starts or stops.
●You may hear cooling fan sounds coming from the air intake vents behind the
rear seat.
■Maintenance, repair, recycling, and disposal
Contact your Lexus dealer regarding maintenance, repair, recycling and disposal.
Do not dispose of the vehicle yourself.

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1-1. Hybrid system
1
Before driving
GS_HV_U (OM30C81U)
February 12, 2010 8:52 am
■Hybrid battery air vent
Hybrid battery air vent
There is an air intake vent on the
package tray for the purpose of
cooling the hybrid battery (trac-
tion battery). If the vent becomes
blocked, the hybrid battery may
overheat, leading to a reduction in
hybrid battery output.
Emergency shut off system
The emergency shut off system blocks off the high voltage current and
stops the fuel pump to minimize the risk of electrocution and fuel leakage
when a certain level of impact is detected by the impact sensor. If the
emergency shut off system activates, your vehicle will not restart. To
restart the hybrid system, contact your Lexus dealer.
Energy monitor/consumption screen
You can view the status of your hybrid system on the multi-information
display (P. 168) and the touch screen (P. 242). The following images
are examples only, and may vary slightly from actual conditions.
■Energy monitor
●How to display on the touch screen:
Press .
Touch “Fuel Consumption” on the “Information” screen.
If the “Energy Monitor” screen does not appear, touch “Energy”.
●How to display on the multi-information display:
Push the “DISP” switch on the steering wheel several times to
select the energy monitor display.
STEP1
STEP2
STEP1

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4-3. Do-it-yourself maintenance
GS_HV_U (OM30C81U)
October 13, 2015 12:41 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
●Make sure that the indicator on the “POWER” switch and the “READY” indicator
are both off.
●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 6 8 )
■Safety glasses
Wear safety glasses to prevent flying or falling 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.

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4-3. Do-it-yourself maintenance
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
Engine compartment
■12 volt battery
P. 4 7 0
Engine oil level dipstick
(P. 4 6 2 )
Engine oil filler cap
(P. 463)
Brake fluid reservoir
(P. 468)
Fuse box (P. 4 9 6 )Washer fluid tank
(P. 4 74 )
Gasoline engine/power 
control unit coolant 
reservoir (P. 466)
Electric cooling fans
Condenser (P. 468)
Radiator (P. 468)

466
4-3. Do-it-yourself maintenance
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
Coolant
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the hybrid system is cold.
Reservoir cap
“FULL”
“LOW”
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line.
■If the coolant level drops within a short time after replenishing
Visually check the radiator, hoses, reservoir cap, radiator cap, drain cock and water
pump. 
If you cannot find a leak, have your Lexus dealer pressure test the cap and check for
leaks in the cooling system.
■Coolant selection
Only use “Toyota Super Long Life Coolant” or similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.: “Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50%
deionized water. (Enabled: -31F [-35C])
Canada: “Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45%
deionized water. (Enabled: -44F [-42C])
For more details about coolant, contact your Lexus dealer.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
CAUTION
■When the hybrid system is hot
Do not remove the radiator and reservoir cap.
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing burns or other injuries.
NOTICE
■When adding the coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water
and antifreeze must be used to provide proper lubrication, corrosion protection
and cooling. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.

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4-3. Do-it-yourself maintenance
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
FuseAmpereCircuit
23A/F15Fuel system
24INV W/P10Hybrid system
25IGCT No.120Hybrid system, IGCT No.2, 
IGCT No.3
26FR FOG15Fog light
27FR TAIL10Tail light, rear side marker light
28WA S H20Windshield wipers and washer
29HORN10Horn
30H-LP UPR20Headlight high beam
31DC/DC140Charging system
32RAD FAN60Electric cooling fans
33LH J/B AM80
S/ROOF, FR P/SEAT LH, TV, A/C,
FUEL OPN, FR WIP, H-LP LVL, 
FR S/HTR LH, A/C W/P
34E/G AM60H-LP CLN, FR CTRL-AM, DEICER,
STB AM
35HEATER50Air conditioning system
36DEFOG50Rear window defogger
37ABS230Enhanced VSC, ABS
38RH J/B-AM80
AM1, OBD, STOP SW, TI & TE, 
FR P/SEAT RH, STR LOCK, 
SECURITY, ECU-IG R, RH-IG, 
F S/HTR RH, CIG, PWR OUTLET, 
AIR SUS

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4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
FuseAmpereCircuit
39RR J/B80STOP LP R, STOP LP L, RR TAIL,
PSB, RR FOG, RR-IG1
40OIL PMP60Tr a n s m i s s i o n
41EPS80EPS
42P/ I - B 160EFI, F/PMP, INJ
43E/G-B30EM-VLV, FR CTRL-B, ETCS
44MAIN30H-LP R LWR, H-LP L LWR
45VGRS40VGRS
46ABS150ABS MOTOR, ABS MAIN1, 
ABS MAIN2
47P/ I - B 260A/F, BATT FAN, IGCT, INV W/P
48BATT FAN20Electric cooling fans
49RAD No.130Audio system
50RAD No.230Audio system
51IG2 MAIN20IG2, GAUGE, IGN
52TURN-HAZ15Front turn signal lights, rear turn 
signal lights
53ABS MAIN310Electronically controlled brake sys-
tem
54ECU-B10VGRS, EPS

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4-3. Do-it-yourself maintenance
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
■Left side instrument panel
FuseAmpereCircuit
1FR WIP30Windshield wipers and washers
2RR-IG7. 5RR-IG1
3LH-IG10
Emergency flashers, seat belt preten-
sioners, headlight cleaners, exhaust
system, rear window defogger, elec-
tric cooling fans, front left door con-
trol system, rear left door control
system
4H-LP LVL7. 5Adaptive front lighting system
5A/C W/P7. 5Air conditioning system
6RAD NO.310Audio system
7FR DOOR LH20Front left door control system
8RR DOOR LH20Rear left door control system
9FR S/HTR LH15Seat heaters, seat heaters and venti-
lators

580
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
CAUTION
■Avoiding battery fires or explosions
Observe the following precautions to prevent accidentally igniting the flammable
gas that may be emitted from the battery.
●Make sure the jumper cable is connected to the correct terminal and that it is not
unintentionally in contact with any part other than the intended terminal.
●Do not allow the jumper cables to come into contact with the “+” and “-” termi-
nals.
●Do not allow open flame or use matches, cigarette lighters or smoke near the
battery.
■Battery precautions
The battery contains poisonous and corrosive acidic electrolyte, while related parts
contain lead and lead compounds. Observe the following precautions when han-
dling the battery:
●When working with the battery, always wear safety glasses and take care not to
allow any battery fluids (acid) to come into contact with skin, clothing or the vehi-
cle body.
●Do not lean over the battery.
●If the battery fluid comes into contact with the skin or eyes, immediately wash the
affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medical attention can be
received.
●Always wash your hands after handling the battery support, terminals, and other
battery-related parts.
●Do not allow children near the battery.
NOTICE
■When handling jumper cables
Be careful that the jumper cables do not become tangled in the cooling fan or any
of the belts when connecting or disconnecting them.