cooling Lexus ES300h 2015 User Guide

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ES350_300h_OM_OM33B36U_(U)
7-3. Do-it-yourself maintenance
■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 engine is hot
Do not remove the engine/power control unit coolant reservoir cap or the radiator
cap.
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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ES350_300h_OM_OM33B36U_(U)
7-3. Do-it-yourself maintenance
FuseAmpereCircuit
1WIP-S5Driver support system, windshield wipers
2FA N50Electric cooling fan
3H-LP CLN30No circuit
4ENG W/PMP*130Cooling system
5PTC HTR NO.250PTC heater
6PTC HTR NO.150PTC heater
7HTR50Air conditioning system
8ALT*2140Charging system
DC/DC*1120Hybrid system
9ABS NO.2*230VSC, ABS
10ST/AM2*230Starting system
ABS NO.1*130VSC, ABS
11H-LP-MAIN30H-LP RH-LO, H-LP LH-LO
12ABS MTR NO.2*150VSC, ABS
13ABS NO.1*250VSC, ABS
ABS MTR NO.1*150VSC, ABS
14R/B NO.2*150IGCT MAIN, INV W/PMP
15EPS80Electric power steering
16S-HORN7. 5S-HORN
17DEICER15Windshield wiper de-icer
18HORN10Horn
19TV15
Multi-information display, audio display,
Remote Touch, audio system, gauges and
meters
20AMP NO.230Audio system
21EFI NO.215
Multiport fuel injection system, sequential
multiport fuel system, electronic controlled
transmission

ES350_300h_OM_OM33B36U_(U)
5937-3. Do-it-yourself maintenance
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Maintenance and care
■Engine compartment (type B fuse box) (hybrid vehicles only)
FuseAmpereCircuit
1BATT FAN7. 5Battery cooling fan
2INV W/PMP RLY7. 5INV W/PMP RLY
3DC/DC IGCT10Hybrid system
4INV7. 5Hybrid system
5BATT VL SSR10Hybrid system
6PM IGCT7. 5Power management system, hybrid system
7IGCT-MAIN25INV W/PMP RLY, INV, DC/DC IGCT,
BATT VL SSR, PM IGCT, BATT FAN
8INV W/PMP15Hybrid system

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ES350_300h_OM_OM33B36U_(U)
7-3. Do-it-yourself maintenance
■Driver’s side instrument panel
FuseAmpereCircuit
1ECU-IG1 NO.210
Main body ECU, audio system, shift lock sys-
tem, outside mirror control ECU, tension
reducer, windshield wipers, heated steering
wheel, multi-information display, audio dis-
play, intuitive parking assist, tire pressure
warning system, moon roof, auto anti-glare
inside rear view mirror, raindrop sensor, rear
sunshade, wireless door lock system, power
trunk opener and closer ECU
2ECU-IG1 NO.110
Electric cooling fan, windshield wiper de-
icer, VSC, ABS, charging system, steering
sensor, electronic controlled transmission,
electric power steering, gateway ECU, elec-
tric tilt and telescopic steering column
3PA N E L N O. 25Clock
4TA I L15Parking lights, side marker lights, license
plate lights
5DOOR F/R20Power window, outside mirror control ECU
6DOOR R/R20Po w e r w i n d o w
7DOOR F/L20Power window, outside mirror control ECU
8DOOR R/L20Po w e r w i n d o w
9H-LP LVL7. 5Automatic headlight leveling system
10WA S H E R10Windshield washer
11A/C-IG17. 5Air conditioning system, PTC heater, gauges
and meters, seat heaters and ventilators

6838-2. Steps to take in an emergency
ES350_300h_OM_OM33B36U_(U)
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When trouble arises
CAUTION
■12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic electrolyte, while
related parts contain lead and lead compounds. Observe the following precau-
tions when handling the 12-volt battery:
●When working with the 12-volt battery, always wear safety glasses and take care
not to allow any battery fluids (acid) to come into contact with skin, clothing or the
vehicle body.
●Do not lean over the 12-volt battery.
●In the event that battery fluid comes into contact with the skin or eyes, immedi-
ately 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 12-volt battery.
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in
the cooling fans or engine drive belt.

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ES350_300h_OM_OM33B36U_(U)
8-2. Steps to take in an emergency
If your vehicle overheats (gasoline vehicles)
Stop the vehicle in a safe place and turn off the air conditioning system,
and then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down sufficiently, inspect the hoses and
radiator core (radiator) for any 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. 97) enters
the red zone or a loss of engine power is experienced. (For example,
the vehicle speed does not increase.)
●Steam comes out from under the hood.
Correction procedures
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6898-2. Steps to take in an emergency
ES350_300h_OM_OM33B36U_(U)
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When trouble arises
The coolant level is satisfactory if it is between the “FULL” and “LOW”
line on the reservoir.Reservoir
“FULL”
“LOW”
Radiator cap
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Start the engine and turn the air conditioning system on to check that
the radiator cooling fans 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 system on and off
repeatedly. (The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately an d contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
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6908-2. Steps to take in an emergency
ES350_300h_OM_OM33B36U_(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.
●Keep hands and clothing (especially a tie, a scarf or a muffler) away from the fans
and belts. Failure to do so may cause the hands or clothing to be caught, resulting
in serious injury.
●Do not loosen the radiator cap or the coolant reservoir cap while the engine and
radiator are hot. High temperature steam or coolant could spray out.
NOTICE
■When adding engine coolant
Add coolant slowly after the engine has cooled down sufficiently. Adding cool
coolant to a hot engine too quickly can cause damage to the engine.
■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.

6928-2. Steps to take in an emergency
ES350_300h_OM_OM33B36U_(U)
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 coolant level is satisfactory if it is between the “FULL” and
“LOW” line on the reservoir.Reservoir
“FULL”
“LOW”
Radiator cap
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
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6938-2. Steps to take in an emergency
ES350_300h_OM_OM33B36U_(U)
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When trouble arises
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fans 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.
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