2020 Lexus GS350 coolant temperature

388
GS350_GS F_OM_OM30J07U_(U)6-3. Do-it-yourself maintenance
The coolant level is satisfactory if it
is between the “FULL”/“F” and “LOW”/“L”
lines on the reservoir when the engine is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” lin e, add coolant up to the “FULL” line.
(  P. 509)
■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 mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -31 F [-35 C])
Canada:
“Toyota Super Long Life Cool ant” 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 coolant reservoir caps, drain cock and water
pump.
If you cannot find a leak, have your Lexus de aler test the cap and check for leaks in the
cooling system.
Coolant
1
2
3
GS350GS F

433
GS350_GS F_OM_OM30J07U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If you think something is wrong
●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 nor-
mal.
●Changes in exhaust sound
●Excessive tire squeal when cornering
●Strange noises related to the suspension system
●Pinging or other noises related to the engine
●Engine missing, stumbling or running roughly
●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
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
Audible symptoms
Operational symptoms

4507-2. Steps to take in an emergency
GS350_GS F_OM_OM30J07U_(U)
Indicates that the engine coolant temperature is too highA buzzer also sounds.
 P. 509
(GS350 only)
Indicates a malfunction in the vehicle’s charging system.
Immediately stop the vehicle in a safe place and
contact your Lexus dealer. Continuing to drive the
vehicle may be dangerous.
(If equipped)
Indicates that the radar sensor is dirty or covered with
ice A buzzer also sounds.
 Clean the sensor.
Warning messageDetails/Actions

509
GS350_GS F_OM_OM30J07U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge (P. 92, 98) enters the
red zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display.
●Steam is coming from under the hood.
Stop the vehicle in a safe place and tu rn 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 cooling
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.
Correction procedures
1
2
3
1
2

5107-2. Steps to take in an emergency
GS350_GS F_OM_OM30J07U_(U)
The coolant level is satisfactory if it is between the “FULL”/“F” and “LOW”/“L”
lines on the reservoir.
Engine coolant reservoir
“FULL”/“F”
“LOW”/“L”
Coolant inlet cap
Add coolant if necessary.
Water can be used in an emerge ncy if coolant is unavailable.
Start the engine and turn the air conditio ning system on to check that the radi-
ator 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.)
4
1
2
3
4
GS350GS F
5
GS350GS F
6

5127-2. Steps to take in an emergency
GS350_GS F_OM_OM30J07U_(U)
WARNING
■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 h ood, 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 seri-
ous 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 foreig n matter (such as sand or dust etc.).
●Do not use any coolant additive.
●GS350: Do not loosen the coolant inlet capor the engine coolant reservoir cap while the
engine and radiator are hot.
High temperature steam or coolant could
spray out.
●GS F: Do not loosen the engine coolant res-
ervoir cap while the engine and radiator are
hot.
High temperature steam or coolant could
spray out.

GS350_GS F_OM_OM30J07U_(U)
5378-1. Specifications
8
Vehicle specifications
■Temperature A, B, C
The temperature grades are A (the highest), B, and C, representing the tire’s
resistance to the generation of heat and its ability to dissipate heat when
tested under controlled conditions on a specified indoor laboratory test
wheel.
Sustained high temperature can cause the ma terial of the tire to degenerate and
reduce tire life, and excessive temperature can lead to sudden tire failure.
Grade C corresponds to a level of perfor mance which all passenger car tires must
meet under the Federal Motor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels of performance on the laboratory test
wheel than the minimum required by law.
Warning: The temperature grades of a tire assume that it is properly inflated and
not overloaded.
Excessive speed, underi nflation, or excessive loading, either separately or in com-
bination, can cause heat buildup and possible tire failure.
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pressure
Tire pressure when the vehicle has been parked for
three hours or more, or has not been driven more than 1
mile or 1.5 km un der that condition
Maximum inflation pres-
sureThe maximum cold inflated pr essure to which a tire may
be inflated, shown on the sidewall of the tire
Recommended inflation
pressureCold tire inflation pressure recommended by a manu-
facturer
Accessory weight
The combined weight (in exce ss of those standard items
which may be replaced) of automatic transmission,
power steering, power brakes, power windows, power
seats, radio and heater, to the extent that these items are
available as factory-installed equipment (whether
installed or not)
Curb weight
The weight of a motor vehicle with standard equipment,
including the maximum capacity of fuel, oil and coolant,
and if so equipped, air co nditioning and additional
weight optional engine
Maximum loaded vehicle
weight
The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant weight150 lb. (68 kg) times the numb er of occupants specified
in the second column of Table 1
* that follows

582Alphabetical index
GS350_GS F_OM_OM30J07U_(U)
Eco drive mode ...................................... 281
Eco Driving Indicator...............................91
Eco driving meter .................................... 98
EDR (Event data recorder) ...................10
Electric Power Steering (EPS) ....... 298Function ................................................. 298
Warning light .......................................436
Warning message ............................. 442
Electronic key ......................................... 138 Battery-saving function .................... 158
If the electronic key does not operate properly............................ 502
Replacing the battery .......................... 411
Emergency, in case of If a warning buzzer sounds...........435
If a warning light turns on...............435
If a warning message is displayed ........................................ 442
If the electronic key does not operate properly ....... 502
If the engine will not start............... 498
If the vehicle is trapped in rising water ........................................426
If the parking brake cannot be released ....................... 500
If the vehicle battery is discharged ........................................ 505
If you have a flat tire ..............473, 484
If you think something is wrong...............................................433
If your vehicle becomes stuck ...... 513
If your vehicle has to be stopped in an emergency .............................425
If your vehicle needs to be towed ....................................... 427
If your vehicle overheats ............... 509 Emergency flashers .............................424
Emergency tire puncture repair
kit ............................................................. 484
Engine Accessory mode ............................... 204
Compartment ...................................... 381
Engine switch ...................................... 203
Hood........................................................ 378
How to start the engine.................. 203
Identification number........................ 518
Ignition switch (engine switch.................................. 203
Overheating........................................ 509
Engine compartment cover............. 383
Engine coolant ...................................... 388 Capacity................................................. 522
Checking .............................................. 388
Preparing and checking before winter ....................................305
Engine coolant temperature gauge .............................................. 92, 100
Engine immobilizer system .................. 77
Engine oil ................................................. 385 Capacity...................................................519
Checking ...............................................385
Oil level warning message ........... 442
Oil pressure warning message........................... 442
Preparing and checking before winter ....................................305
E