2010 Lexus GS450h coolant level

450
4-2. Maintenance
GS_HV_U (OM30C81U)
January 28, 2010 10:42 am
General maintenance
Engine compartment
Luggage compartment
ItemsCheck points
Brake fluid• At the correct level? (P. 4 6 8 )
Engine/power control unit coolant• At the correct level? (P. 4 6 6 )
Engine oil• At the correct level? (P. 4 6 2 )
Exhaust system• No fumes or strange sounds?
Radiator/condenser/hoses• Not blocked with foreign matter? 
(P. 4 6 8 )
Wa s h e r f l u i d• At the correct level? (P. 4 74 )
ItemsCheck points
12 volt battery• Maintenance-free (P. 4 7 0 )
Listed below are the general maintenance items that should be performed
at the intervals specified in the “Warranty and Services Guide/Owner’s
Manual Supplement”. It is recommended that any problem you notice
should be brought to the attention of your Lexus dealer or qualified service
shop for advice.

454
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
4-3. Do-it-yourself maintenance
Do-it-yourself service precautions
If you perform maintenance yourself, be sure to follow the correct proce-
dure given in these sections.
ItemsPa r t s a n d t o o l s
12 volt battery condition (P. 4 7 0)
•Grease
• Conventional wrench
(for terminal clamp bolts)
Brake fluid level (P. 4 6 8 )
• FMVSS No.116 DOT 3 or SAE
J1703 brake fluid
•Rag or paper towel
• Funnel (used only for adding brake
fluid)
Engine/power control unit coolant
level (P. 4 6 6 )
• “Toyota Super Long Life Coolant”
or similar high quality ethylene gly-
col based non-silicate, non-amine,
non-nitrite and non-borate coolant
with long-life hybrid organic acid
technology.
For the U.S.A.:
“Toyota Super Long Life Coolant”
is pre-mixed with 50% coolant and
50% deionized water.
For Canada:
“Toyota Super Long Life Coolant”
is pre-mixed with 55% coolant and
45% deionized water.
• Funnel (used only for adding cool-
ant)

460
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.

5
When trouble arises
531
5-1. Essential information
GS_HV_U (OM30C81U)
January 28, 2010 10:42 am
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■Visible symptoms
●Fluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
●Flat-looking tires or uneven tire wear
●Engine coolant temperature gauge needle continually points
higher than normal
■Audible symptoms
●Changes in exhaust sound
●Excessive tire squeal when cornering
●Strange noises related to the suspension system
●Pinging or other noises related to the hybrid system
■Operational symptoms
●Engine missing, stumbling or running rough
●Appreciable loss of power
●Vehicle pulls heavily to one side when braking
●Vehicle pulls heavily to one side when driving on a level road
●Loss of brake effectiveness, spongy feeling, pedal almost touches
the floor

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