Page 429 of 652
429
GS450h_OM_OM30E26U_(U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Engine compartment
■12-volt battery
P. 4 3 9
Engine oil level dipstick
(P. 4 3 1 )
Engine coolant reservoir (P. 4 3 4 )
Engine oil filler cap ( P. 4 3 2 )
Power control unit coolant
reservoir ( P. 4 3 4 ) Brake fluid reservoir
(P. 4 3 7 )
Fuse box ( P. 4 6 2 )
Washer fluid tank ( P. 4 3 8 )
Electric cooling fans
Condenser ( P. 436)
Radiator ( P. 436)1
2
3
4
5
6
7
8
9
10
Page 435 of 652

GS450h_OM_OM30E26U_(U)
4356-3. Do-it-yourself maintenance
6
Maintenance and care
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a 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. (Minimum temperature: -31 F [-35C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deionized
water. (Minimum temperature: -44 F [-42C])
For more details about coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/power control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in
the cooling system.
CAUTION
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or the cool-
ant inlet cap. ( P. 5 7 0 )
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding 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.
Page 567 of 652

5677-2. Steps to take in an emergency
GS450h_OM_OM30E26U_(U)
7
When trouble arises
The coolant level is satisfactory if it is between the “FULL” and
“LOW” lines on the reservoir.
Reservoir
“FULL”
“LOW”
Coolant inlet cap
Add coolant if necessary.
( P. 569)
Water can be used in an emer-
gency if engine coolant is unavail-
able.
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fa ns operate and to check for coolant
leaks from the radiator or hoses.
The fans operate when the air conditioning system is turned on immediately
after a cold start. Confirm that the fans are operating by checking the fan
sound and air flow. If it is difficult to check these, turn the air conditioning sys-
tem on and off repeatedly. (The fans may not operate in freezing tempera-
tures.)
If the fans are not operating:
Stop the hybrid system immediately and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
4
1
2
3
4
5
6
7
Page 570 of 652

5707-2. Steps to take in an emergency
GS450h_OM_OM30E26U_(U)
CAUTION
■When inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
●If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartment may be very hot.
●After the hybrid system has been turned off, check that the indicator on the
power switch and the “READY” indicator are off.
When the hybrid system is operating, the gasoline engine may automatically
start, or the cooling fan may suddenly oper ate even if the gasoline engine stops.
Do not touch or approach rotating parts such as the fan, which may lead to fin-
gers or clothing (especially a tie, a scarf or a muffler) getting caught, resulting in
serious injury.
NOTICE
■When adding engine/power control unit coolant
Add coolant slowly after the hybrid syst em has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too quickly can cause da mage to the hybrid
system.
■To prevent damage to the cooling system
Observe the following precautions:
●Avoid contaminating the coolant with foreign matter (such as sand or dust etc.).
●Do not use any coolant additives.
●Do not loosen the cool ant inlet cap or the
coolant reservoir cap while the hybrid sys-
tem and radiator are hot.
High temperature steam or coolant could
spray out.
Page 645 of 652

645Alphabetical index
GS450h_OM_OM30E26U_(U)
Pre-Collision System (PCS) ..............291Function ................................................... 291
PCS OFF switch ................................293
Warning light ...................................... 505
Warning message .......................515, 526, 532
Radar cruise control (dynamic radar cruise control) ........................ 240
Radiator .................................................... 436
Radio
*
RBDS (Radio Broadcast Data Systems)
*
Rear air conditioning system ........... 355
Rear door sunshades ..........................388
Rear personal lights............................. 364
Rear side marker lights ........................ 217 Light switch ............................................. 217
Replacing light bulbs ....................... 489
Welcome light illumination cont rol ..........................123
Rear seat heaters.................................. 382
Rear sunshade ....................................... 387 Operation ..............................................387
Reverse operation feature............ 388 Rear turn signal lights ......................... 209
Replacing light bulbs ....................... 487
Turn signal lever ................................. 209
Wattage .................................................583
Rear view mirror Inside rear view mirror...................... 162
Outside rear view mirrors ..............164
Rear view monitor system
*
Rear window defoggers .................... 360
Refueling.................................................... 231 Capacity................................................. 576
Fuel types............................................... 576
Opening the fuel tank cap ............ 233
When the fuel filler door cannot be opened ......................... 234
Regenerative braking............................. 74
Remote Touch
*.....................................326
Replacing Electronic key battery .....................460
Fuses ........................................................ 462
Light bulbs............................................. 479
Tires ............................................................541
Reporting safety defects for U.S. owners .................................... 612
Resetting the message indicating maintenance is required .................. 416
Road accident cautions ......................... 79
R
*: Refer to the “NAVIGATION AND MULTIMEDIA SYSTEM OWNER’S MANUAL”.