brake LEXUS GS300H 2019 Repair Manual

3324-6. Driving tips
GS450h_300h_OM_OM30F92E_(EE)
◆Delays
Repeated acceleration and deceleration, as well as long waits at traffic lights,
will lead to bad fuel economy. Check traffic reports before leaving and avoid
delays as much as possible. When driving in a traffic jam, gently release the
brake pedal to allow the vehicle to move forward slightly while avoiding over-
use of the accelerator pedal. Doing so can help control excessive gasoline
consumption.
◆Highway driving
Control and maintain the vehicle at a constant speed. Before stopping at a toll
booth or similar, allow plenty of time to release the accelerator and gently
apply the brakes. A greater amount of electrical energy can be regenerated
when slowing down.
◆Air conditioning
Use the air conditioning only when necessary. Doing so can help reduce
excessive gasoline consumption.
In summer: When the ambient temperature is high, use the recirculated air
mode. Doing so will help to reduce the burden on the air conditioning system
and reduce fuel consumption as well.
In winter: Because the gasoline engine will not automatically cut out until it
and the interior of the vehicle are warm, it will consume fuel. Also, fuel con-
sumption can be improved by avoiding overuse of the heater.
◆Checking tire inflation pressure
Make sure to check the tire inflation pressure frequently. Improper tire infla-
tion pressure can cause poor fuel economy.
Also, as snow tires can cause large amounts of friction, their use on dry roads
can lead to poor fuel economy. Use ti res that are appropriate for the season.

3344-6. Driving tips
GS450h_300h_OM_OM30F92E_(EE)
Winter driving tips
●Use fluids that are appropriate to the prevailing outside temperatures.
•Engine oil
• Engine/power control unit coolant
•Washer fluid
●Have a service technician inspect the condition of the 12-volt battery.
●Have the vehicle fitted with four snow tires or purchase a set of tire chains for
the rear tires.*
Ensure that all tires are the specified size and brand, and that chains match the size of the tires.
*: Tire chains cannot be mounted on vehicles with front and rear tires of differing
sizes and vehicles with LDH and 19 inch tires
Perform the following according to the driving conditions:
●Do not try to forcibly open a window or move a wiper that is frozen. Pour
warm water over the frozen area to melt the ice. Wipe away the water imme-
diately to prevent it from freezing.
●To ensure proper operation of the climate control system fan, remove any
snow that has accumulated on the air inlet vents in front of the windshield.
●Check for and remove any excess ice or snow that may have accumulated on
the exterior lights, vehicle’s roof, chassis, around the tires or on the brakes.
●Remove any snow or mud from the bottom of your shoes before getting in the
vehicle.
Carry out the necessary preparations an d inspections before driving the vehi-
cle in winter. Always drive the vehicle in a manner appropriate to the prevail-
ing weather conditions.
Preparation for winter
Before driving the vehicle

3354-6. Driving tips
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
Accelerate the vehicle slowly, keep a safe distance between you and the vehicle
ahead, and drive at a reduced speed suitable to road conditions.
●Park the vehicle and move the shift lever to P without setting the parking
brake. The parking brake may freeze up, preventing it from being released. If
the vehicle is parked without setting the parking brake, make sure to block the
wheels.
Failure to do so may be dangerous because it may cause the vehicle to move
unexpectedly, possibly leading to an accident.
●If the vehicle is parked without setting the parking brake, confirm that the shift
lever cannot be moved out of P*.
*: The shift lever will be locked if it is attemp ted to be shifted from P to any other position
without depressing the brake pedal. If the shift lever can be shifted from P, there may
be a problem with the shift lock system. Have the vehicle inspected by any authorized
Lexus retailer or Lexus authorized repair er, or any reliable repairer immediately.
When driving the vehicle
When parking the vehicle

3916-1. Maintenance and care
6
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
■High-pressure car washes
●Do not allow the nozzles of the car wash to come within close proximity of the windows.
●Before using the car wash, check that the fuel filler door on your vehicle is closed prop-
erly.
■Notes for a smart entry & start system (vehicles with entry function)
If the door handle becomes wet while the electronic key is within the effective range, the
door may lock and unlock repeatedly. In that case, follow the following correction proce- dures to wash the vehicle:
●Place the key in a position 2 m (6 ft.) or more separate from the vehicle while the vehi-
cle is being washed. (Take care to ensure that the key is not stolen.)
●Set the electronic key to battery-saving mode to disable the smart entry & start system. ( P. 155)
■Aluminum wheels
●Remove any dirt immediately by using a neutral detergent. Do not use hard brushes or abrasive cleaners. Do not use strong or harsh chemical cleaners.
Use the same mild detergent and wax as used on the paint.
●Do not use detergent on the wheels when they are hot, for example after driving for long distance in the hot weather.
●Wash detergent from the wheels immediately after use.
■Brake caliper coating (vehicles with orange brake calipers for F SPORT models)
●When using detergent, use neutral detergent.
Do not use hard brushes or abrasive clea ners, as they will damage the coating.
●Do not use detergent on the brake calipers when they are hot.
●Wash detergent off immediately after use.
■Bumpers
Do not scrub with abrasive cleaners.
■Front side windows water-repellent coating
●The following precautions can extend the effectiveness of the water-repellent coating.
• Remove any dirt, etc. from the front side windows regularly.
• Do not allow dirt and dust to accumulate on the windows for a long period. Clean the windows with a soft, damp cloth as soon as possible.• Do not use wax or glass cleaners that co ntain abrasives when cleaning the windows.
• Do not use any metallic objects to remove condensation build up.
●When the water-repellent performance has become insufficient, the coating can be
repaired. Contact any authorized Lexus reta iler or Lexus authorized repairer, or any reliable repairer.

3936-1. Maintenance and care
6
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
NOTICE
■To prevent paint deterioration and corrosion on the body and components (aluminum wheels etc.)
●Wash the vehicle immediately in the following cases:
• After driving near the sea coast • After driving on salted roads• If coal tar, pollen or tree sap is present on the paint surface
• If dead insects, insect droppings or bird droppings are present on the paint surface • After driving in an area contaminated wi th soot, oily smoke, mine dust, iron pow- der or chemical substances
• If the vehicle becomes heavily soiled with dust or mud • If liquids such as benzene and gaso line are spilled on the paint surface
●If the paint is chipped or scratched, have it repaired immediately.
●To prevent the wheels from corroding, remove any dirt and store in a place with low humidity when storing the wheels.
■Cleaning the exterior lights
●Wash carefully. Do not use organic subs tances or scrub with a hard brush. This may damage the surfaces of the lights.
●Do not apply wax to the surfaces of the lights.Wax may cause damage to the lenses.
■When using an automatic car wash (vehicle s with rain-sensing windshield wipers)
Turn off AUTO mode of the wiper to prevent the wiper from operating. (P. 251) If AUTO mode is selected, the wipers may operate and the wiper blades may be dam-aged.
■When using a high-pressure car wash
●When washing the vehicle, do not let water from the high-pressure washer directly hitthe camera or the area around the camera. Due to the shock from high-pressure
water, it is possible that the device may not operate normally.
●Do not bring the nozzle tip close to boots (rubber or resin manufactured cover), con- nectors or the following parts. The parts may be damaged if they come into contact
with high-pressure water.
• Traction related parts
•Suspension parts
•Steering parts
• Brake parts

3986-2. Maintenance
GS450h_300h_OM_OM30F92E_(EE)
■Does your vehicle need repairs?
Be on the alert for changes in performance and sounds, and visual tip-offs that indicate service is needed. Some important clues are:
●Engine missing, stumbling or pinging
●Appreciable loss of power
●Strange engine noises
●A fluid leak under the vehicle (However, water dripping from the air conditioning sys-tem after use is normal.)
●Change in exhaust sound (This may indicate a dangerous carbon monoxide leak. Drive
with the windows open and have the exhaust system checked immediately.)
●Flat-looking tires, excessive tire sque al when cornering, uneven tire wear
●Vehicle pulls to one side when driven straight on a level road
●Strange noises related to suspension movement
●Loss of brake effectiveness, spongy feeling brake pedal, pedal almost touches the floor, vehicle pulls to one side when braking
●Engine coolant temperature continually higher than normal ( P. 105)
If you notice any of these clues, take your vehicle to any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer as soon as possible. Your vehicle may
need adjustment or repair.
WARNING
■If your vehicle is not properly maintained
Improper maintenance could result in serious damage to the vehicle and possible death or serious injury.
■Handling of the 12-volt battery
12-volt battery posts, terminals and related accessories contain lead and lead com- pounds which are known to cause brain damage. Wash your hands after handling.
( P. 412)

4006-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
WARNING
The engine compartment contains many mechanisms and fluids that may move suddenly, become hot, or become electrically energize d. 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 co ntrol 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 enginecompartment.
●Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes are flamma-
ble.
●Take care because brake fluid can harm your hands or eyes and damage painted sur- faces. If fluid gets on your hands or in your eyes, flush the affected area with clean
water immediately. If you still experi ence discomfort, consult a doctor.
■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. 411)
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from getting 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.
■If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear or when the fluid level in the accumulator is high.
If the reservoir needs frequent refillin g, it may indicate a serious problem.

451
7When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
7-1. Essential information
Emergency flashers ..................452
If your vehicle has to be
stopped in an
emergency.................................453
7-2. Steps to take in an
emergency
If your vehicle needs
to be towed................................ 454
If you think something
is wrong....................................... 459
If a warning light turns on
or a warning buzzer
sounds..........................................460
If a warning message
is displayed ................................ 466
If you have a flat tire
(vehicles with spare tire) ......498
If you have a flat tire
(vehicles without spare
tire)................................................509
If the hybrid system
will not start................................ 523
If the parking brake
cannot be released................. 525
If the electronic key does
not operate properly ............. 527
If the 12-volt battery is
discharged .................................530
If your vehicle overheats .........535
If the vehicle becomes
stuck ............................................. 542

453
7
7-1. Essential information
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
If your vehicle has to be stopped in an emergency
Steadily step on the brake pedal with both feet and firmly depress it.
Do not pump the brake pedal repeatedly as this will increase the effort required to
slow the vehicle.
Shift the shift lever to N.
If the shift lever is shifted to N
After slowing down, stop the vehicle in a safe place by the road.
Stop the hybrid system.
If the shift lever cannot be shifted to N
Keep depressing the brake pedal with both feet to reduce vehicle speed as
much as possible.
To stop the hybrid system, press and
hold the power switch for 2 consec-
utive seconds or more, or press it
briefly 3 times or more in succes-
sion.
Stop the vehicle in a safe place by the road.
Only in an emergency, such as if it becomes impossible to stop the vehicle in
the normal way, stop the vehicl e using the following procedure:
1
2
3
4
3
Press and hold for 2 seconds or more
or press briefly 3 times or more
4
WARNING
■If the hybrid system has to be turned off while driving
Power assist for the steering wheel will be lost, making the steering wheel heavier to turn. Decelerate as much as possible before turning off the hybrid system.
5

4567-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
If a tow truck is not available in an emergency, your vehicle may be temporarily
towed using cables or chains secured to the emergency towing eyelets. This
should only be attempted on hard surfaced roads for short distances at under
30 km/h (18 mph).
A driver must be in the vehicle to steer and operate the brakes. The vehicle’s
wheels, drive train, axles, steering and brakes must be in good condition.
Take out the towing eyelet. ( P. 499, 511)
Remove the eyelet cover using a flathead screwdriver.
To protect the bodywork, place a rag between the screwdriver and the vehicle body
as shown in the illustration.
Insert the towing eyelet into the hole
and tighten partially by hand.
Emergency towing
Emergency towing procedure
1
2
Except F SPORT modelsF SPORT models
3