2019 LEXUS GS300H engine

411 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.
If any washer does not work or the
warning message appears on the multi-
information display, the washer tank
may be empty. Add washer fluid.
Radiator and condenser
WARNING
■When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause serious injuries, such as burns.
Washer fluid
WARNING
■When adding washer fluid
Do not add washer fluid when the hybrid sy stem is hot or operating as washer fluid contains alcohol and may catch fi re if spilled on the engine etc.
NOTICE
■Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid.
Doing so may cause streaking on the vehicle’s painted surfaces.
■Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the label of the washer fluid bottle.

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6
6-3. Do-it-yourself maintenance
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
Checking and replacing fuses
Turn the power switch off.
Open the fuse box cover.
Engine compartment:
Remove the engine compartment
cover ( P. 405) and remove all of the
clips.
Push the tabs on either side to detach
the lock and lift the lid off while pulling
the lock plate.
When installing the lid, check that the lock plate and the tabs on either side are
connected correctly.
If any of the electrical components do not operate, a fuse may have blown. If
this happens, check and repl ace the fuses as necessary.
1
2

4426-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
Light bulbs
Check the wattage of the light bulb to be replaced. ( P. 558)
 P. 405
Front turn signal light (vehicles with single-beam headlights)
Outer foot light
You may replace the following bulbs by yourself. The difficulty level of replace-
ment varies depending on the bulb. As there is a danger that components may
be damaged, we recommend that replacement is carried out by any autho-
rized Lexus retailer or Lexus authorized repairer, or any reliable repairer.
Preparing for light bulb replacement
Removing the engine compartment covers
Bulb locations
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2

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7
7-2. Steps to take in an emergency
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
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 hybrid system
●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 sy mptoms, your vehicle probably needs
adjustment or repair. Contact any authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

4607-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
If a warning light turns on or a warning buzzer
sounds
Calmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, but then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspected by any authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
Brake system warning light (warning buzzer)
•Low brake fluid • Malfunction in the electronically controlled brake system Immediately stop the vehicle in a safe place and contact any
authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer. Continuing to drive the vehicle may be dan-gerous.
(If equipped)
Charging system warning light
Indicates a malfunction in the vehicle’s charging system  Immediately stop the vehicle in a safe place and contact any authorized Lexus retailer or Lexus authorized repairer, or any
reliable repairer.
Malfunction indicator lamp Indicates a malfunction in:• The hybrid system;
• The emission control system (if equipped); • The electronic engine control system; • The electronic throttle control system; or
• The electronic hybrid transmission control system (if equipped)  Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.
SRS warning light
Indicates a malfunction in: • The SRS airbag system; or• The seat belt pretensioner system
 Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.

4687-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
Indicates a malfunction in the gasoline engine or that the
shift lever is in N for a long period of time A buzzer also sounds. Release the accelerator pedal and change the shift
position to D, S or R.
Indicates that the driver’s door was opened with the shift position in any position other than PA buzzer also sounds.
 Shift the shift position to P.
Indicates a malfunction in the hybrid system A buzzer also sounds.
 Immediately stop the vehicle in a safe place and contact any authorized Lexus retailer or Lexusauthorized repairer, or any reliable repairer.
Indicates that hood or one or more of the doors or trunkare not fully closed
The system also indicates which hood or doors or trunk are not fully closed.If the vehicle reaches a speed of 5 km/h (3 mph),
flashes and a buzzer sounds to indicate that
the hood or door(s) or trunk are not yet fully closed.
 Make sure that hood or all doors or trunk are closed.
Warning messageDetails/Actions
(Flashes)
(Flashes)

4747-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
(If equipped)
Indicates that steering control function is temporarily canceled due to the LKA (L ane-Keeping Assist) system determining that the driver does not have their hands on
the steering wheel while the steering control function is onA buzzer also sounds.
 Firmly hold the steering wheel.
Indicates that the parking brake system is overheating A buzzer also sounds.
 Do not use the parking brake until the message dis- appears.
Indicates an engine malfunction
A buzzer also sounds.  Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer.
Indicates an engine malfunction A buzzer also sounds. Have the vehicle inspected by any authorized Lexus
retailer or Lexus authorized repairer, or any reliable repairer.
Warning messageDetails/Actions

4757-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
Indicates a malfunction in:
• The SRS airbag system; or • The seat belt pretensioner systemA buzzer also sounds.
 Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliablerepairer.
Indicates a malfunction in:•The ABS; or• The brake assist system
A buzzer also sounds.  Immediately stop the vehicle in a safe place and contact any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.
Indicates that the engine coolant temperature is too high
A buzzer also sounds.  P. 535
Indicates a malfunction in the vehicle’s charging system.  Immediately stop the vehicle in a safe place and contact any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.
Warning messageDetails/Actions