2018 Lexus GS450h check engine

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GS450h_OM_OM30G62U_(U)
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6-3. Do-it-yourself maintenanceDo-it-yourself service precautions................................ 349
Hood ................................................ 351
Positioning a floor jack ............ 352
Engine compartment ............... 353
12-volt battery ............................. 362
Tires ................................................. 365
Tire inflation pressure .............. 375
Wheels ........................................... 378
Air conditioning filter ...............380
Electronic key battery.............. 382
Checking and replacing fuses.............................................. 384
Headlight aim (vehicles with single-beam head lights) ...... 389
Light bulbs ......................................391
7-1. Essential information Emergency flashers .................. 396
If your vehicle has to be stopped in an emergency.... 397 7-2. Steps to take in an emergency
If your vehicle needs to be towed ............................... 398
If you think something is wrong................ 403
If a warning light turns on or a warning buzzer sounds .... 404
If a warning message is displayed ................................. 410
If you have a flat tire ....................441
If the hybrid system will not start ............................... 450
If the parking brake cannot be released................................ 452
If the electronic key does not operate properly..................... 454
If the 12-volt battery is discharged............................. 457
If your vehicle overheats...........461
If the vehicle becomes stuck ............................................. 466
7When trouble arises

15Pictorial index
GS450h_OM_OM30G62U_(U)
Windshield wipers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 207
Precautions against winter season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 276
To prevent freezing (windshield wiper de-icer)
*. . . . . . . . . . . . . . . . . . . . . . . P. 293
Precautions against car wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 338
Fuel filler door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 213
Refueling method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 213
Fuel type/fuel tank capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 472
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 365
Tire size/inflation pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 477
Winter tires/tire chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 27 6
Checking/rotation/tire pressure warning system . . . . . . . . . . . . . . . . . . . . . . P. 365
Coping with flat tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P . 441
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 351
Opening. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 351
Engine compartment cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 354
Engine oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 473
Coping with overheat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 46 1
Warning messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 4 12
Headlights/front side marker lights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 200
Front turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 195
Parking lights/daytime running lights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 200
Side turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 195
Tail lights/rear side marker lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 200
Rear turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 195
Stop lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 168
Back-up light
Shifting the shift lever to R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 189
License plate lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 200
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Light bulbs of the exte rior lights for driving
(Replacing method: P. 391, Watts: P. 480)
*: If equipped
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GS450h_OM_OM30G62U_(U)
2. Instrument cluster
WARNING
■The information display at low temperatures
Allow the interior of the vehicle to warm up before using the liquid crystal information
display. At extremely low temperatures, th e information display monitor may respond
slowly, and display changes may be delayed.
For example, there is a lag between the dr iver’s shifting and the new gear number
appearing on the display. This lag could ca use the driver to downshift again, causing
rapid and excessive engine braking and possibly an accident resulting in death or
injury.
NOTICE
■To prevent damage to the hybr id system and its components
●While the tachometer is displayed, do not let the indicator needle of the tachometer
enter the red zone, which indicates the maximum engine speed.
●The engine may be overheating if the engine coolant temperature gauge is in the red
zone (H). In this case, immediately stop the vehicle in a safe place, and check the
engine after it has cooled completely. (→ P. 461)

GS450h_OM_OM30G62U_(U)
1714-1. Before driving
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Driving
WARNING
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When starting the vehicle
Always keep your foot on the brake pedal while stopped with the “READY” indicator is
illuminated. This prevents the vehicle from creeping.
■When driving the vehicle
●Do not drive if you are unfamiliar with the location of the brake and accelerator ped-
als to avoid depressing the wrong pedal.
• Accidentally depressing the accelerator pedal instead of the brake pedal will
result in sudden acceleration that may lead to an accident.
• When backing up, you may twist your body around, leading to a difficulty in oper-
ating the pedals. Make sure to operate the pedals properly.
• Make sure to keep a correct driving po sture even when moving the vehicle only
slightly. This allows you to depress th e brake and accelerator pedals properly.
• Depress the brake pedal using your right foot. Depressing the brake pedal using your left foot may delay re sponse in an emergency, resulting in an accident.
●The driver should pay extra attention to pedestrians when the vehicle is powered only
by the electric motor (traction motor). As there is no engine noise, the pedestrians
may misjudge the vehicle’s movement. Even though the vehicle is equipped with the
vehicle proximity notification system, drive wi th care as pedestrians in the vicinity may
still not notice the vehicle if the surrounding area is noisy.
●Do not drive the vehicle over or stop the vehicle near flammable materials.
The exhaust system and exhaust gases can be extremely hot. These hot parts may
cause a fire if there is any flammable material nearby.
●During normal driving, do not turn off the hybrid system. Turning the hybrid system off
while driving will not cause loss of steering or braking control, however, power assist
to the steering will be lost. This will make it more difficult to steer smoothly, so you
should pull over and stop the vehicle as soon as it is safe to do so.
In the event of an emergency, such as if it becomes impossible to stop the vehicle in
the normal way: → P. 397
●Use engine braking (downshift) to maintain a safe speed when driving down a steep
hill.
Using the brakes continuously may cause th e brakes to overheat and lose effective-
ness. ( →P. 189)
●Do not adjust the positions of the steering wheel, the seat, or the inside or outside rear
view mirrors while driving.
Doing so may result in a loss of vehicle control.
●Always check that all passengers’ arms, heads or other parts of their body are not
outside the vehicle.
●Do not drive in excess of the speed limit. Even if the legal speed limit permits it, do not
drive over 85 mph (140 km/h) unless your vehicle has high-speed capability tires.
Driving over 85 mph (140 km/h ) may result in tire failure, loss of control and possible
injury. Be sure to consult a tire dealer to determine whether the tires on your vehicle
are high-speed capability tires or no t before driving at such speeds.

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GS450h_OM_OM30G62U_(U)
4-1. Before driving
WARNING
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When driving on slippery road surfaces
●Sudden braking, acceleration and steering may cause tire slippage and reduce your
ability to control the vehicle.
●Sudden acceleration, engine braking due to shifting, or changes in engine speed
could cause the vehicle to skid, resulting in an accident.
●After driving through a puddle , lightly depress the brake pedal to make sure that the
brakes are functioning properly. Wet brake pads may prevent the brakes from func-
tioning properly. If the brakes on only on e side are wet and not functioning properly,
steering control may be affected.
■When shifting the shift lever
●Do not let the vehicle roll backward while the shift lever is in a driving position, or roll
forward while the shift lever is in R.
Doing so may result in an acci dent or damage to the vehicle.
●Do not shift the shift lever to P while the vehicle is moving.
Doing so can damage the transmission and may result in a loss of vehicle control.
●Do not shift the shift lever to R while the vehicle is moving forward.
Doing so can damage the transmission and may result in a loss of vehicle control.
●Do not shift the shift lever to a driving position while the vehicle is moving backward.
Doing so can damage the transmission and may result in a loss of vehicle control.
●Shifting the shift lever to N while the vehicle is moving will disengage the hybrid sys-
tem. Engine braking is not available with the hybrid system disengaged.
●Be careful not to shift the shift lever with the accelerator pedal depressed. Shifting the
shift lever to any position other than P or N may lead to unexpected rapid accelera-
tion of the vehicle that may cause an accide nt and result in death or serious injury.
■If you hear a squealing or scraping noise (brake pad wear limit indicators)
Have the brake pads checked and replaced by your Lexus dealer as soon as possible.
Rotor damage may result if the pads are not replaced when needed.
Front brakes of F SPORT models: Moderate levels of brake pad and disc wear allow
enhanced front braking power. As a result, the discs may wear more quickly than con-
ventional brake discs. Therefore, when replacing the brake pads, Lexus recommends
that you also have the thic kness of the discs measured.
It is dangerous to drive the vehicle when the wear limits of the brake pads and/or those
of the brake discs are exceeded.

GS450h_OM_OM30G62U_(U)
1754-1. Before driving
4
Driving
NOTICE
■If you get a flat tire while driving
A flat or damaged tire may cause the following situations . Hold the steering wheel
firmly and gradually depress the brake pedal to slow down the vehicle.
●It may be difficult to control your vehicle.
●The vehicle will make abnormal sounds or vibrations.
●The vehicle will lean abnormally.
Information on what to do in case of a flat tire ( →P. 441)
■When encountering flooded roads
Do not drive on a road that has flooded af ter heavy rain etc. Doing so may cause the
following serious damage to the vehicle:
●Engine stalling
●Short in electrical components
●Engine damage caused by water immersion
In the event that you drive on a flooded road and the vehicle is flooded, be sure to have
your Lexus dealer check the following:
●Brake function
●Changes in quantity and quality of oil and fluid used for the engine, hybrid transmis-
sion, differential, etc.
●Lubricant condition for the propeller shaft, bearings and suspension joints (where
possible), and the function of all joints, bearings, etc.

GS450h_OM_OM30G62U_(U)
1934-2. Driving procedures
4
Driving
■Automatic deactivation of shift range selection in the D position
Shift range selection in the D position will be deactivated in the following situations:
●When the vehicle comes to a stop
●If the accelerator pedal is depressed fo r more than a certain period of time
●When the shift lever is shifted to other than D
■Downshifting restrictions warning buzzer
To help ensure safety and driving performance, downshifti ng operation may sometimes
be restricted. In some circum stances, downshifting may not be possible even when the
shift lever or paddle shif t switch is operated. (A buzzer will sound twice.)
■Snow mode automatic deactivation
Snow mode is automatically deactivated if th e power switch is turned off after driving in
snow mode.
■When driving with cruise control or dynamic radar cruise control with full-speed range
activated
Even when performing the following actions with the intent of enabling engine braking,
engine braking will not activate because crui se control, dynamic radar cruise control or
dynamic radar cruise control with full-speed range will not be canceled.
●While driving in the D position or S mode, downshifting to 7, 6, 5 or 4. ( →P. 243, 255)
●When switching the driving mode to spor t mode while driving in D position. (→P. 258)
■Restraining sudden start (Drive-Start Control)
●When the following unusual operation is pe rformed, the hybrid system output may be
restrained.
• When the shift lever is shifted from R to D, D to R, N to R, P to D, or P to R (D
includes S) with the acce lerator pedal depressed, a warning message appears on
the multi-information display. ( →P. 410)
• When the accelerator pedal is depressed t oo much while the vehicle is in reverse.
■Shift lock system
The shift lock system is a system to prevent ac cidental operation of the shift lever in start-
ing.
The shift lever can be shifted from P only wh en the power switch is in ON mode and the
brake pedal is being depressed.
■If the shift lever cannot be shifted from P
First, check whether the brak e pedal is being depressed.
If the shift lever cannot be shifted with your foot on the brake pedal, there may be a prob-
lem with the shift lock system. Have the vehi cle inspected by your Lexus dealer immedi-
ately.
The following steps may be used as an emergency measure to ensure that the shift lever
can be shifted.
Releasing the shift lock:
Press the parking brake switch to chec k that the parking brake is set. (→P. 196)
Parking brake indicator will come on.
Turn the power switch to off.
Depress the brake pedal.
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GS450h_OM_OM30G62U_(U)
2754-6. Driving tips
4
Driving
◆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 drivin g 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 co nstant speed. Before stopping at a toll
booth or similar, allow plenty of ti me 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 av oiding overuse of the heater.
◆Checking tire inflation pressure
Make sure to check the tire inflation pr essure frequently. Improper tire infla-
tion pressure can cause poor fuel economy.
Also, as snow tires can cause large amou nts of friction, their use on dry roads
can lead to poor fuel economy. Use tires that are appropriate for the season.
◆Luggage
Carrying heavy luggage will lead to poor fuel economy. Avoid carrying
unnecessary luggage. Installing a large roof rack will also cause poor fuel
economy.
◆Warming up before driving
Since the gasoline engine starts up an d cuts out automatically when cold,
warming up the engine is unnecessary. Moreover, frequently driving short dis-
tances will cause the engine to repeated ly warm up, which can lead to excess
fuel consumption.