2015 Lexus GS350 cooling

GS350_OM_OM30E15U_(U)
4036-3. Do-it-yourself maintenance
6
Maintenance and care
CAUTION
■When the engine is hot
Do not remove the engine coolant reservoir cap or the coolant inlet cap.(P. 5 3 1 )
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.

GS350_OM_OM30E15U_(U)
4336-3. Do-it-yourself maintenance
6
Maintenance and care
9DOME7. 5
Personal lights, ornament lights, trunk light,
footwell lights, door courtesy lights, vanity
lights, rear door inside handle illuminations,
power trunk opener and closer
10EPS80EPS
11ARS80Dynamic rear steering
12HTR50Air conditioning system
13ABS NO.140VDIM
14LUG J/B ALT50Luggage compartment junction block
15PTC NO.150PTC heater
16PTC NO.250PTC heater
17ABS NO.250VDIM
18ST30Starting system
19H-LP LO30Headlights, H-LP RLY
20D/C CUT30DOME, MPX-B
21DCM7. 5DCM
22ECU-B7. 5VGRS, smart access system with push-but-
ton start
23ALT-S7. 5Charging system
24ETCS10Multiport fuel injection system/sequential
multiport fuel injection system
25HORN10Horn
26R/B-B20EPS-B, ODS, TV
27P/ I - B N O.150Headlights, daytime running lights
28EPB30Parking brake
29LUG J/B-B40Luggage compartment junction block
30FAN NO.180Electric cooling fans
31LH J/B ALT60Left-hand junction block
32H-LP CLN30Headlight cleaner
FuseAmpereCircuit

434
GS350_OM_OM30E15U_(U)
6-3. Do-it-yourself maintenance
■Engine compartment (type B fuse box)
33FAN NO.240Electric cooling fans
34A/C COMP7. 5Air conditioning system
35FILTER10Condenser
FuseAmpereCircuit
FuseAmpereCircuit
1IGN10Starting system
2INJ10Multiport fuel injection system/sequential
multiport fuel injection system
3EFI NO.210Fuel system, exhaust system
4IG2 MAIN20IGN, GAUGE, INJ, AIR BAG, IG2 NO.1,
LH-IG2
5EFI MAIN25Multiport fuel injection system/sequential
multiport fuel injection system, EFI NO.2
6A/F15Air intake system
7EDU20Multiport fuel injection system/sequential
multiport fuel injection system
8F/ P M P25Multiport fuel injection system/sequential
multiport fuel injection system
9SPARE30Spare fuse

5287-2. Steps to take in an emergency
GS350_OM_OM30E15U_(U)
CAUTION
■Battery precautions
The battery contains poisonous and corrosive acidic electrolyte, while related
parts contain lead and lead compounds. Observe the following precautions when
handling the battery:
●When working with the battery, always wear safety glasses and take care not to
allow any battery fluids (acid) to come into contact with skin, clothing or the vehi-
cle body.
●Do not lean over the 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 th e battery support, terminals, and other
battery-related parts.
●Do not allow children near the 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.

529
GS350_OM_OM30E15U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats
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. 81) enters
the red zone or a loss of engine power is expe rienced. (For example,
the vehicle speed does not increase.)
●Steam is coming from under the hood.
Correction procedures
1
2
3
1
2

5307-2. Steps to take in an emergency
GS350_OM_OM30E15U_(U)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.
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 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, tu rn 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 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

5317-2. Steps to take in an emergency
GS350_OM_OM30E15U_(U)
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 (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.
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.
●Do not loosen the cool ant inlet cap or the
coolant reservoir cap while the engine and
radiator are hot.
High temperature steam or coolant could
spray out.

540
GS350_OM_OM30E15U_(U)
8-1. Specifications
Cooling system
Capacity 10.3 qt. (9.7 L, 8.5 Imp.qt.)
Coolant typeUse either of the following:• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based non-silicate, non-amine, non-nitrite, and non-borate coolant with
long-life hybrid organic acid technology
Do not use plain water alone.
Ignition system
Spark plug
Make
GapDENSO FK20HBR11
0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.