2015 Lexus GS450h cooling

GS450h_OM_OM30F70U_(U)
4256-3. Do-it-yourself maintenance
6
Maintenance and care
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 “POWER ON” on the multi-information display 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 and 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 fans or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the electric cooling fans may automatically
start to run if the air conditioning is on and/or the coolant temperature is high.
(→ P. 4 3 6 )
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from get-
ting in your 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.
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429
GS450h_OM_OM30F70U_(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. 4 3 6 )
Radiator ( →P. 4 3 6 )1
2
3
4
5
6
7
8
9
10
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GS450h_OM_OM30F70U_(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 [-35 °C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deionized
water. (Minimum temperature: -44 °F [-42 °C])
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.
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468
GS450h_OM_OM30F70U_(U)
6-3. Do-it-yourself maintenance
34DOME7. 5
Personal lights, ornament lights, trunk light,
footwell lights, door courtesy lights, vanity
lights, rear door inside handle illuminations,
power trunk opener and closer
35MPX-B10
Body ECU, smart access system with push-
button start, electric tilt and telescopic steer-
ing column, power seats, head-up display,
front door ECU, gauges and meters, steer-
ing sensor, yaw rate and G sensor, overhead
module, RR CTRL SW, power trunk opener
and closer, clock, CAN gateway ECU
36IGCT NO.410Power control unit
37IGCT NO.37. 5Hybrid battery (traction battery), DC/DC
converter
38IGCT NO.25Hybrid system
39IG2 NO.15DCM, CAN gateway ECU
40GAUGE5Gauges and meters
41DC/DC150RH-J/B DC/DC, P/I DC/DC,
LH-J/B DC/DC, LUG-J/B DC/DC
42P/ I D C / D C100RR S/SHADE, DEFOG, FOG, TAIL,
PA N E L
43RH J/B DC/DC80Right-hand junction block
44LH J/B DC/DC50Left-hand junction block
45H-LP CLN30No circuit
46FA N N O. 240Electric cooling fans
47LUG J/B DC/DC80Luggage compartment junction block
48FA N N O.180Electric cooling fans
49PTC NO.150PTC heater
50PTC NO.250PTC heater
51HTR50Air conditioning system
FuseAmpereCircuit
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470
GS450h_OM_OM30F70U_(U)
6-3. Do-it-yourself maintenance
■Driver’s side instrument panel
FuseAmpereCircuit
1STOP7. 5Stop lights, high mounted stoplight
2P/ W- B5Power window master switch
3P/ S E AT 1 F/ L30Po w e r s e a t s
4D/L NO.125Po w e r d o o r l o c k s y s t e m
5NV-IR10Lexus night view
6FL S/HTR10Seat heaters/ventilators
7WIPER30Windshield wipers
8WIPER-IG5Windshield wipers
9LH-IG10
Seat belts, body ECU, AFS, overhead mod-
ule, raindrop sensor, inside rear view mirror,
lane camera sensor (LKA), head-up display,
shift lock system, intuitive parking assist, front
left-hand door ECU, driver monitor system,
Remote Touch screen, electric tilt and tele-
scopic steering column, power seats, moon
roof, windshield wiper de-icer, intuitive park-
ing assist switch, PTC heater, Blind Spot
Monitor buzzer
10LH ECU-IG10
VDIM, brake system, D-SW MODULE
(Blind Spot Monitor, heated steering wheel),
driver support system, AFS, electric cooling
fans, EPB, air conditioning system, steering
sensor
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474
GS450h_OM_OM30F70U_(U)
6-3. Do-it-yourself maintenance
■Tr u n k
FuseAmpereCircuit
1PSB30Pre-collision seat belts
2PTL25Power trunk opener and closer
3RR J/B-B10Smart access system with push-button start
4RR S/HTR20Seat heaters (rear)
5FR S/HTR10Seat heaters/ventilators (front)
6RR FOG10No circuit
7DC/DC-S (HV)7. 5DC/DC converter
8BATT FAN (HV)20Hybrid battery (traction battery) cooling fan
system
9SECURITY7. 5SECURITY
10ECU-B NO.37. 5Pa r k i n g b r a ke
11TRK OPN7. 5Power trunk opener and closer, trunk open
motor
12DCM (HV)7. 5DCM
13AC INV (HV)20Po w e r o u t l e t ( 1 2 0 V AC )
14RR-IG15Radar sensor, Blind Spot Monitor
15RR ECU-IG10
Power trunk opener and closer, parking
brake, tension reducer (rear left-hand), RR
CTRL SW, tire pressure warning system
16EPS-IG5Electric power steering system
17BACK UP7. 5Back-up lights, Remote Touch screen
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5337-2. Steps to take in an emergency
GS450h_OM_OM30F70U_(U)
7
When trouble arises
Carrying out the corresponding action turns the messages off.
*: For the EV drive mode operating conditions: →P. 2 0 0
Other displayed messages
Displayed messageDetailsCorrection procedure
Maintenance of the
hybrid system (traction
battery) cooling compo-
nent is required
The filter may be
clogged, the air vent
may be blocked or
there may be a gap in
the duct.
Have maintenance per-
formed on the hybrid sys-
tem (traction battery)
cooling component at
your Lexus dealer.
Indicates that the EV
drive mode is not avail-
able
*
The reason the EV
drive mode is not avail-
able (the vehicle is
idling, battery charge is
low, speed is higher
than the EV drive
mode operating speed
range, accelerator
pedal is depressed too
much) may be dis-
played.
Use the EV drive mode
when it becomes avail-
able.
Indicates that the EV
drive mode has been
automatically canceled
*
The reason the EV
drive mode is not avail-
able (the battery
charge is low, speed is
higher than the EV
drive mode operating
speed range, accelera-
tor pedal is depressed
too much) may be dis-
played.
Drive the vehicle for a
while.
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566
GS450h_OM_OM30F70U_(U)
7-2. Steps to take in an emergency
If your vehicle overheats
■If the needle of the engine coolant temperature gauge enters the red
zone
Stop the vehicle in a safe place and turn off the air conditioning sys-
tem, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has cooled down sufficiently, inspect the
hoses and cooling system for leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact your
Lexus dealer.
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( →P. 91) enters
the red zone or a loss of hybrid system power is experienced. (For
example, the vehicle speed does not increase.)
●“Hybrid System Overheat” ( →P. 527) is shown on the multi-informa-
tion display.
●Steam comes out from under the hood.
Correction procedures
1
2
3
1
2
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