brake Lexus GS300h 2017 Workshop Manual

3284-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
■Sounds and vibrations caused by the ABS, brake assist, VSC, Hill-start assist control,
TRC and VGRS systems
Any of the following conditions may occur when the above systems are operating. None
of these indicates that a malfunction has occurred.
●Vibrations may be felt through the vehicle body and steering.
●A motor sound may be heard after the vehicle comes to a stop.
■ECB operation sound
ECB operating sound may be heard in the follow ing cases, but it does not indicate that a
malfunction has occurred.
●Operating sound heard from the engine compartment when the brake pedal is oper-
ated.
●Motor sounds of the brake system heard from the front part of the vehicle when the
driver’s door is opened.
●Operating sound heard from the engine compartment when one or two minutes
passed after the stop of the hybrid system.
■EPS, VGRS and DRS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.
■Automatic reactivation of TRC and VSC systems
After turning the TRC and VSC systems off, the systems will be automatically re-enabled
in the following situations:
●When the power switch is turned off
●If only the TRC system is turned off, the TR C will turn on when vehicle speed increases
If both TRC and VSC systems are turned off, automatic re-enabling will not occur when
vehicle speed increases.
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating
when there is frequent steering input over an extended period of time. The steering
wheel may feel heavy as a result. Should this occur, refrain from excessive steering input
or stop the vehicle and turn the hybrid system off. The EPS system should return to nor-
mal within 10 minutes.
■Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate;
●The shift lever is in a position other than N or P (when starting off forward/backward on
an upward incline).
●The vehicle is stopped.
●The accelerator pedal is not depressed.
●The parking brake is not engaged.

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4-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■Automatic system cancelation of hill-start assist control
The hill-start assist control will be canc eled in any of the following situations;
●The shift lever is shifted to N or P.
●The accelerator pedal is depressed.
●The parking brake is engaged.
●Approximately 2 seconds elapse after the brake pedal is released.
■Operating conditions of emergency brake signal
When the following three conditions are me t, the emergency brake signal will operate:
●The emergency flashers are off.
●Actual vehicle speed is over 55 km/h (35 mph).
●The brake pedal is depressed in a manner that cause the system to judge from the vehi-
cle deceleration that this is a sudden braking operation.
■Automatic system cancelation of emergency brake signal
The emergency brake signal will turn off in any of the following situations:
●The emergency flashers are turned on.
●The brake pedal is released.
●The system judges from the vehicle deceleration that is not a sudden braking operation.
WARNING
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road).
●The vehicle hydroplanes while driving at high speed on wet or slick roads.
■Stopping distance when the ABS is operat ing may exceed that of normal conditions
The ABS is not designed to shorten the vehicle’s stopping distance. Always maintain a
safe distance from the vehicle in front of you, especially in the following situations:
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or uneven surfaces
■TRC may not operate effectively when
Directional control and power may not be achievable while driving on slippery road
surfaces, even if the TRC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
■Hill-start assist control does not operate effectively when
●Do not overly rely on the hill-start assist co ntrol. The hill-start assist control may not
operate effectively on steep inclines and roads covered with ice.
●Unlike the parking brake, hill-start assist co ntrol is not intended to hold the vehicle
stationary for an extended period of time. Do not attempt to use hill-start assist con-
trol to hold the vehicle on an incline, as doing so may lead to an accident.

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4
4-6. Driving tips
Driving
GS450h_300h_OM_OM30F92E_(EE)
Hybrid vehicle driving tips
◆Using Eco drive mode
When using Eco drive mode, the torque corresponding to the accelerator
pedal depression amount can be generated more smoothly than it is in normal
conditions. In addition, the operation of the air conditioning system (heating/
cooling) will be minimized, improving the fuel economy. ( P. 311)
◆Use of Hybrid System Indicator
The Eco-friendly driving is possible by keeping the indicate of Hybrid System
Indicator within Eco area. ( P. 108, 123)
◆Shift lever operation
Shift the shift lever to D when stopped at a traffic light, or driving in heavy traf-
fic etc. Shift the shift lever to P when parking. When using the N, there is no
positive effect on fuel consumption. In the N, the gasoline engine operates but
electricity cannot be generated. Also, when using the air conditioning system,
etc., the hybrid battery (traction battery) power is consumed.
◆Accelerator pedal/brake pedal operation ● Drive your vehicle smoothly. Avoid abrupt acceleration and deceleration.
Gradual acceleration and deceleration will make more effective use of the
electric motor (traction motor) without having to use gasoline engine
power.
● Avoid repeated acceleration. Repeated acceleration consumes hybrid bat-
tery (traction battery) power, resulting in poor fuel consumption. Battery
power can be restored by driving with the accelerator pedal slightly
released.
◆When braking
Make sure to operate the brakes gently and in a timely manner. A greater
amount of electrical energy can be regenerated when slowing down.
For economical and ecological driving, pay attention to the following points:

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.

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4-6. 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

391
6-1. 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.

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 mech anisms 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 engine
compartment.
●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 t he affected area with clean
water immediately. If you still experience 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