Page 637 of 860
637
GS450h_U (OM30D01U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Engine compartment
■12-volt battery
P. 6 4 7
Engine oil level dipstick
(P. 6 3 9 )
Engine coolant reservoir (P. 6 4 2 )
Engine oil filler cap (P. 640)
Power control unit coolant res-
ervoir ( P. 6 4 2 )Brake fluid reservoir
(P. 645)
Fuse box ( P. 670)
Washer fluid tank ( P. 646)
Electric cooling fans
Condenser ( P. 644)
Radiator ( P. 644)1
2
3
4
5
6
7
8
9
10
Page 642 of 860
642
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the hybrid system is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. ( P. 7 74 )
■Power control unit coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. ( P. 7 74 )
Coolant
1
2
3
1
2
3
Page 643 of 860

GS450h_U (OM30D01U)
6436-3. 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 un it coolant reservoir caps or the radia-
tor cap.( P. 777)
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 777 of 860

7777-2. Steps to take in an emergency
GS450h_U (OM30D01U)
7
When trouble arises
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.
●Keep hands and clothing away from the fans , etc. while the hybrid system is oper-
ating.
●For vehicles with a hybrid system, there are times when the gasoline engine auto-
matically starts to run or the cooling fans suddenly start to operate. Do not touch
or approach the rotating parts of the belt or fans. Doing so may lead to fingers,
clothes or tools getting caught, resulting in 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 commercially available coolant additives.
●Do not loosen the radiator cap or the cool-
ant reservoir caps while the hybrid system
and radiator are hot.
High temperature steam or coolant could
spray out.