2010 Lexus GS450h cooling

504
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.

5
When trouble arises
581
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 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. Carefully lift the hood after the
steam subsides and then restart the hybrid system.
If you do not see steam:
Leave the hybrid system operating and carefully lift the
hood.
Remove the engine compartment cover. (P. 4 6 1 )
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 immediately and call your 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

593
6-1. Specifications
6
Vehicle specifications
GS_HV_U (OM30C81U)
February 1, 2010 11:10 am
Cooling system
Ignition system
Capacity
Gasoline engine
Power control unit9.8 qt. (9.3 L, 8.1 Imp.qt.)
3.0 qt. (2.9 L, 2.5 Imp.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 hybrid organic acid technology
Do not use plain water alone.
Spark plug
Make DENSOFK20HBR11
Gap0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust gap when tuning engine.

631
Alphabetical index
GS_HV_U (OM30C81U)
February 1, 2010 11:29 am
Back-up lights
Wattage ................................................. 597
Battery
12 volt battery ...................................... 470
Checking ............................................... 470
Hybrid battery 
(Traction battery) .............................. 28
If the 12 volt battery is 
discharged ........................................ 578
Preparing and checking 
before winter .................................... 233
Bluetooth
® audio ................................... 321
Bluetooth® phone ............................... 345
Brake
Fluid .......................................................... 468
Parking brake ........................................159
Brake assist ............................................... 214
Care
Exterior ....................................................442
Interior..................................................... 445
Seat belts ............................................... 446
Cargo capacity ..................................... 228
Cargo hooks ............................................ 421
CD player/changer ............................ 282
Chains........................................................234
Child-protectors ......................................56
Child restraint system
Definition.................................................. 124
Installation................................................ 128
Installing CRS with lower 
anchors ................................................. 129
Installing CRS with seatbelts ...........131
Installing CRS with top straps .......135Child safety
Airbag precautions .............................. 114
Battery precautions ............. 472, 580
Child restraint system ........................124
Child-protectors ...................................56
How your child should wear 
the seatbelt............................................ 78
Installing child restraints................... 128
Moon roof precautions...................... 93
Power window lock switch .............. 87
Power window precautions ............89
Removed electronic key battery 
precautions....................................... 495
Seat belt comfort guide ..................... 76
Seat belt precautions .......................... 79
Seat heater precautions.................. 414
Trunk precautions................................. 62
Cigarette lighter....................................... 411
Cleaning
Exterior.................................................... 442
Interior .....................................................445
Seat belts ................................................446
Clock ........................................................ 408
Coin holder .............................................403
Compass .................................................. 429
Condenser ..............................................468
Console box ............................................ 401
Cooling system
Engine overheating............................ 581
Cruise control
Cruise control......................................... 181
Dynamic radar cruise control....... 185
Cup holders ............................................404
Curtain shield airbags.......................... 107
Customizable features ........................ 615
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