engine Lexus HS250h 2010 Basic Information Before Operation / LEXUS 2010 HS250H (OM75006U) Service Manual

430
4-3. Do-it-yourself maintenance
Radiator and condenser
Check the radiator and condenser and clear away any foreign objects. 
If either of the above parts is extremely dir
ty or you are not sure of their
condition, have your vehicle inspected by your Lexus dealer.
CAUTION
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps. 
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing burns or other injuries.
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 cooling. 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.
CAUTION
■When the hybrid system is hot
Do not touch the radiators or condense r as they may be hot and cause burns.

432
4-3. Do-it-yourself maintenance
Washer fluid
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.
NOTICE
■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 out or
when the fluid level in the accumulator is high. 
If the reservoir needs frequent refilling, there may be a serious problem.
CAUTION
■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.
■Diluting washer fluid
Dilute washer fluid with water as necessary. 
Refer to the freezing temperatures listed on the washer fluid tank.

455
4-3. Do-it-yourself maintenance
4
Maintenance and care
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may have blown.
If this happens, check and replace the fuses as necessary.
Turn the “POWER” switch off.
Open the fuse box cover.
Engine compartment
Push the tab in and lift the lid off.
Driver’s side instrument panel Remove the lid.
After a system failure, see “Fuse la y
out and amperage ratings”
( P. 4 5 8 ) for details about which fuse to check.

458
4-3. Do-it-yourself maintenance
Fuse layout and amperage ratings
Engine compartment
FuseAmpereCircuit
1HTR50 AAir conditioning system
2RDI40 AElectric cooling fans
3OIL PMP10 AHybrid system, transmission
4S-HORN10 ANo circuit
5ABS MAIN NO.27. 5 AElectronically controlled brake system
6H-LP CLN30 AHeadlight cleaner
7AMP NO.130 AAudio system, back door opener
8IGCT30 APCU, IGCT NO.2, IGCT NO.3,
hybrid system
9P CON MAIN7. 5 A
P position control system, hybrid sys-
tem, smart access system with push-
button start

469
4-3. Do-it-yourself maintenance
4
Maintenance and care
Light bulbs
You may replace the following bulbs by yourself. The difficulty level of
replacement varies depending on the bulb. If necessary bulb replacement
seems difficult to perform, contact your Lexus dealer.

For more information about replacing other light bulbs, contact your Lexus
dealer
.
■Preparing for light bulb replacement
Check the wattage of the light bulb to be replaced. ( P.
5 5 6 )
■ R
emove the engine compartment covers
 P.
4 2 3
■ F
ront bulb locations
Halogen headlights
Front side marker lightHeadlight low beam
Parking light
Front turn signal light
Front fog light
Headlight high beam

5
When trouble arises
489
5-1. Essential information
If you think something is wrong
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
●Fluid leaks under the v
ehicle
(Water dripping from the air conditioning after use is normal.)
● Flat
-looking tires or uneven tire wear
●High engine coolant temper
ature warning light flashes or comes
on
■ A
udible symptoms
●Changes in e
xhaust sound
● Ex
cessive tire squeal when cornering
●Str
ange noises related to the suspension system
●P
inging or other noises related to the hybrid system
■ Oper
ational symptoms
●Engine mis
sing, stumbling or running rough
●A
ppreciable loss of power
●V
ehicle pulls heavily to one side when braking
●V
ehicle pulls heavily to one side when driving on a level road.
● L
oss of brake effectiveness, sp ongy feeling, pedal almost touches
the floor

490
5-1. Essential information
Event data recorder
In a crash or a near crash event
The SRS airbag sensor assembly contains the EDR. In a crash or near
crash event, this device may record some or all of the following informa-
tion:
● Engine speed
● Whether the br
ake pedal was applied or not
● V
ehicle speed
●T
o what extent the accelerator pedal was depressed
●Hybrid tr
ansmission shift position
●Whether the driv
er and front passenger wore seat belts or not
● D
river's seat position
●SRS airbag deplo
yment data
● SRS airbag s
ystem diagnostic data
● F
ront passenger’s occupant classification
The information abov e is intended to be used for the purpose of impr
ov-
ing vehicle safety performance. Unlike general da ta recorders, the EDR
does not record sound data such as conversation between passengers.
Your vehicle has computers that monitor and control certain aspects of
your vehicle. These computers assist in driving and maintaining optimal
vehicle performance.
Besides storing data usef ul for troubleshooting, there is an event data
recorder (EDR) that records data in a crash or near crash event.

5
When trouble arises
493
5-2. Steps to take in an emergency
Have the vehicle inspected by your Lexus dealer immediately.
Failing to investigate the cause of the following warnings may lead to the
system operating abnormally and possibly cause an accident. Have the
vehicle inspected by your Lexus dealer immediately.
High engine coolant temperatur e warning light (flashes or
comes on) Indicates that the engine is overheating P. 5 4 1
• Flashes: Engine is overheating. Drive carefully.
• Comes on: Engine is overheated. Stop the vehicle.
Warning lightWarning light/Details
Brake system warning light (yellow indicator) Indicates a malfunction in:
• The regenerative brake system; or
• The electronically controlled brake system
(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 hybrid transmission control system
SRS warning lightIndicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
(U.S.A.)

(Canada)
“ABS” warning lightIndicates a malfunction in:
•The ABS; or
• The brake assist system
Warning lightWarning light/Details

5
When trouble arises
501
5-2. Steps to take in an emergency
If a warning message is displayed
Stop the vehicle immediately.
A buzzer sounds and a warning message is shown on the multi-informa -
tion display. The following warning ind icates the pos
sibility of damage to
the vehicle that may lead to an acci dent. Immediately stop the vehicle in a
safe place and contact your Lexus dealer.
Wa r n i n g m e s s a g eDetails
Indicates abnormal engine oil pressure
A buzzer also sounds.
The warning message is displayed if the engine oil
pressure is too low.
Indicates a malfunction in the hybrid systemA buzzer also sounds.
If a warning is shown on the multi-information display, stay calm and per-
form the following actions:
Master warning light
The master warning light also
comes on or flashes in order to
indicate that a message is cur -
rently being displayed on the
multi-information display
.
Multi-information display
If any of the warning light comes on again af
ter the following actions
have been performed, contact your Lexus dealer.

506
5-2. Steps to take in an emergency
(Flashes)
(If equipped)
Indicates that the moon
roof is not fully closed A buzzer also sounds.
(With the “POWER”
switch off, and the
driver's door open)
Close the moon roof.
Indicates that the parking
brake is still engagedIf the vehicle reaches a
speed of 3 mph 
(5 km/h),
flashes and a buzzer
sounds to indicate that
the parking brake is still
engaged.
Release the parking
brake.
Indicates that the washer
fluid level is lowAdd washer fluid.
(U.S.A. only)
Indicates that the engine
oil is scheduled to be
changed
Check the engine oil, and
change if necessary.
Comes on approximately
4500 miles (7200 km)
after the engine oil is
changed. 
(The indicator will not
work properly unless the
oil maintenance data has
been reset.)
Wa r n i n g m e s s a g eDetailsCorrection procedure