2018 Lexus GS450h engine

GS450h_OM_OM30G62U_(U)
3596-3. Do-it-yourself maintenance
6
Maintenance and care
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 your Lexus dealer.
WARNING
■When the hybrid system is hot
Do not remove the engine/power control un it coolant reservoir caps or the coolant
inlet cap. ( →P. 465)
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water and
antifreeze must be used to provide proper lubrication, corrosion protection and cool-
ing. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
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.

GS450h_OM_OM30G62U_(U)
3616-3. Do-it-yourself maintenance
6
Maintenance and care
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.
Washer fluid
WARNING
■When adding washer fluid
Do not add washer fluid when the hybrid system is hot or operating as washer fluid
contains alcohol and may catch fire 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, as well as damaging
the pump leading to problems of the washer fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the label of the washer fluid bottle.

384
GS450h_OM_OM30G62U_(U)
6-3. Do-it-yourself maintenance
Checking and replacing fuses
Turn the power switch off.
Open the fuse box cover.
Engine compartment
Remove the engine compartment
cover (→P. 354) 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

391
GS450h_OM_OM30G62U_(U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Light bulbs
Check the wattage of the light bulb to be replaced. ( →P. 480)
→ P. 354
Front turn signal light (vehicles with single-beam headlights)
You may replace the following bulbs by yo urself. The difficulty level of replace-
ment varies depending on the bulb. If necessary bulb replacement seems diffi-
cult to perform, contact your Lexus dealer.
For more information about replacing other light bulbs, contact your Lexus
dealer.
Preparing for light bulb replacement
Removing the engine compartment covers
Bulb locations
1

403
GS450h_OM_OM30G62U_(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 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 symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

404
GS450h_OM_OM30G62U_(U)
7-2. Steps to take in an emergency
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 inspecte d by your Lexus dealer.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
(U.S.A.)
(Canada)
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 your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
(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 your
Lexus dealer.
(U.S.A.)
(Canada)
Malfunction indicator lamp Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The electronic hybrid transmission control system
→ Have the vehicle inspected by your Lexus dealer immediately.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
→ Have the vehicle inspected by your Lexus dealer immediately.
(U.S.A.)
(Canada)
ABS warning light Indicates a malfunction in:
• The ABS; or
• The brake assist system
→ Have the vehicle inspected by your Lexus dealer immediately.

4127-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
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 stop the vehicle
in a safe place and shift the shift lever to P.
Indicates that the driver’s door was opened with the shift
position in any position other than P
A 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 your Lexus dealer.
Indicates that hood or one or more of the doors or trunk
are not fully closed
The system also indicates which hood or doors or
trunk are not fully closed.
If the vehicle reaches a speed of 3 mph (5 km/h),
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)

4187-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
Indicates that the parking brake system is overheatingA 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 your Lexus dealer.
Indicates an engine malfunction
A buzzer also sounds.
→ Have the vehicle inspected by your Lexus dealer.
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupa nt classification system;
or,
• The seat belt pretensioner system
A buzzer also sounds.
→ Have the vehicle inspected by your Lexus dealer.
Warning messageDetails/Actions
(U.S.A.) (Canada)
(U.S.A.) (Canada)
(U.S.A.) (Canada)