engine overheat Lexus HS250h 2010 Owner's Manual

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HS250h_U_75033U(Canada)
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4-1. Maintenance and careCleaning and protecting the vehicle exterior................... 402
Cleaning and protecting the vehicle interior .................... 406
4-2. Maintenance Maintenance requirements.............................. 409
General maintenance ................... 411
Emission inspection and maintenance (I/M)
programs ....................................... 415
4-3. Do-it-yourself maintenance Do-it-yourself service precautions ................................... 416
Hood................................................... 419
Positioning a floor jack ............... 420
Engine compartment.................. 422
12-volt battery................................ 433
Tires ................................................... 437
Tire inflation pressure................. 445
Wheels.............................................. 448
Air conditioning filter................. 450
Electronic key battery ................ 453
Checking and replacing fuses ................................................ 455
Headlight aim (LED headlights) ....................... 467 Light bulbs ....................................... 469
5-1. Essential information Emergency flashers .................... 482
If your vehicle needs to be towed ............................................ 483
If you think something is wrong ............................................ 489
Event data recorder.................... 490
5-2. Steps to take in an emergency If a warning light turns on or a warning buzzer
sounds... ......................................... 492
If a warning message is displayed ........................................ 501
If you have a flat tire...................... 521
If the hybrid system will not start ................................................ 530
If you lose your keys .................... 532
If the electronic key does not operate properly ............... 533
If the vehicle 12-volt battery is discharged ............................... 536
If your vehicle overheats ............ 541
If the vehicle becomes stuck................................................ 545
If your vehicle has to be stopped in
an emergency.............................. 547
4Maintenance and care
5When trouble arises

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2-1. Driving procedures
HS250h_U_75033U(Canada)
CAUTION
●Do not select shift position R when the vehicle is rolling forward, do not select D
when moving in reverse, and do not press the P position switch before the vehicle
stops fully. Doing so will cause the buzzer to sound and the shift position to
change to N. In addition, excessive force will be applied to the powertrain and
damage may result.
●Do not change the shift position to N while the vehicle is moving.
Doing so may cause insufficient engine braking, resulting in an accident.
●Do not turn the hybrid system off while driving.
The power steering and brake actuator will not operate properly if the hybrid sys-
tem is off.
●Use engine braking (shift position B) to maintain a safe speed when driving down
a steep hill.
Using the brakes continuously may cause the brakes to overheat and lose effec-
tiveness. (→P. 1 5 3 )
●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 that can cause accidents, resulting
in death or serious injury.
●Always check that all passengers' arms, heads or other parts of their body are not
outside the vehicle, as this may result in death or serious injury.
●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 not before driving at such speeds.
■When driving on slippery road surfaces
●Sudden braking, acceleration and steering may cause tire slippage and reduce
your ability to control the vehicle, resulting in an accident.
●Abrupt changes from shift position D to B and rapid changes in the 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
functioning properly. If the brakes on only one side are wet and not functioning
properly, steering control may be affected, resulting in an accident.

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2-1. Driving procedures
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When driving
HS250h_U_75033U(Canada)
CAUTION
■When changing the shift position
Be careful not to change the shift position with the accelerator pedal depressed.
Changing the shift position to any positions other than P or N may cause the vehicle
to accelerate abruptly, causing an accident and resulting in death or serious injury.
■If you hear a squealing or scraping noise (brake pad wear limit indicators)
Have your Lexus dealer check and replace the brake pads as soon as possible.
Rotor damage may result if the pads are not replaced when needed.
It is dangerous to drive the vehicle when the wear limits of the brake pads and/or
those of the brake discs are exceeded.
■When the vehicle is stopped
●Do not depress the accelerator pedal unnecessarily.
If the vehicle is in any shift position other than P or N, the vehicle may accelerate
suddenly and unexpectedly, causing an accident.
●Do not leave the vehicle with the hybrid system on for a long time.
If such a situation cannot be avoided, park the vehicle in an open space and
check that exhaust fumes do not enter the vehicle interior.
●In order to prevent accidents due to the vehicle rolling away, always keep
depressing the brake pedal while the “READY” indicator is on. Apply the parking
brake as necessary.
●If the vehicle is stopped on an incline, in order to prevent accidents caused by the
vehicle rolling forward or backward, always depress the brake pedal and securely
apply the parking brake as needed.
●Avoid revving or racing the engine.
Running the engine at high speed while the vehicle is stopped may cause the
exhaust system to overheat, which could result in a fire if combustible material is
nearby.
■When the vehicle is parked
●Do not leave glasses, cigarette lighters, spray cans, or soft drink cans in the vehi-
cle when it is in the sun.
Doing so may result in the following:
• Gas may leak from a cigarette lighter or spray can, and may lead to a fire.
• The temperature inside the vehicle may cause the plastic lenses and plasticmaterial of glasses to deform or crack.

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2-2. Instrument cluster
HS250h_U_75033U(Canada)
■Limitations of brightness adjustment
The brightness of the instrument panel lights is automatically adjusted based on the
light sensor detecting how bright the surroundings are. However, if the instrument
panel brightness has been manually set to either the brightest or dimmest setting,
the automatic adjustment will not be performed.
■Hybrid System Indicator
●By keeping the indicator needle within Eco area, environmentally-friendly driv-
ing can be achieved.
Hybrid Eco area shows that gasoline engine power is not being used very often.*
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●Charge area indicates regeneration*2 status. Regenerated energy will be used
to charge the hybrid battery.
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1: The gasoline engine will automatically stop and restart under various condi- tions.
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2: When used in this manual, “regeneration” refers to the conversion of energy created by the movement of the vehicle into electrical energy.
■Customization
Settings (e.g. Sensitivity of the ambient light sensor used for dimming the meter
lights) can be changed. (Customizable features →P. 5 74 )
NOTICE
■To prevent damage to the hybrid system and its components
A high engine coolant temperature warning light (→ P. 492) is installed instead of
an engine coolant temperature gauge. If the high engine coolant temperature
warning light illuminates or flashes, the vehicle may be overheating. Immediately
stop the vehicle in a safe area ( →P. 5 4 1 ) .
Eco area
Eco Driving Indicator Light comes on
Hybrid Eco area
Eco Driving Indicator Light comes on
Charge area
Eco Driving Indicator Light comes on
Powe r a re a
Eco Driving Indicator Light turns off

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When trouble arises
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5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
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 lampIndicates a malfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The hybrid transmission control system
SRS warning light
Indicates 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

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When trouble arises
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5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
(U.S.A. only)
Indicates that the engine
oil should be changedComes on approxi-
mately 5000 miles
(8000 km) after the
engine oil is changed
(and the oil maintenance
data has been reset)
Check and change the
engine oil.
Indicates that the tire
inflation pressure is lowCheck the tire inflation
pressure, and adjust to the
appropriate level.
(If equipped)
Indicates that the pre-
collision system is not
currently functional
because the grille or the
sensor is dirty.This message also
appears when the pre-
collision system is not
functional due to over-
heating.
Check the grille and the
sensor and clean them if
they are dirty.In case of overheating,
the system will become
functional once the sys-
tem cools down.
(If equipped)
Indicates that intuitive
parking assist sensor is
dirty or covered with ice
A buzzer also sounds.
The site of the malfunc-
tion and the vehicle
image are flashing.
Clean the sensor.
Wa r n i n g m e s s a g eDetailsCorrection procedure

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When trouble arises
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5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
If your vehicle overheats
Correction procedures■ If the engine coolant temperature warning light comes on or flashes
Stop the vehicle in a safe place and turn off the air conditioning
system.
Check to see if steam is coming out from the engine area.
If you see steam:
Stop the hybrid system. Carefully lift the hood after the steam
subsides and then restart the hybrid system.
If you do not see steam:
Leave the hybrid system operating and carefully lift the hood.
Remove the engine compartment cover. ( →P. 423)
Check to see if the cooling fans are operating.
If the fans are operating:
Wait until the high engine coolant temperature warning light goes
off and then stop the hybrid system.
If the fans are not operating:
Stop the hybrid system immediately and call your Lexus dealer.
The following may indicate that your vehicle is overheating:
● The high engine coolant temperature warning light comes on or
flashes:
The engine may be overheating.
● “HYBRID SYSTEM OVERHEAT” is shown on the multi-information
display:
The power control unit may be overheating.
Follow the correction procedure as described below.

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5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)After the hybrid system has cooled
down sufficiently, check the engine
coolant level and inspect the cool-
ing system for leaks.
Add engine coolant if necessary.
Water can be used in an emer-
gency if engine coolant is unavail-
able. (
→P. 5 5 4 )
Have the vehicle inspected at the nearest Lexus dealer as soon as possi-
ble.
■If “HYBRID SYSTEM OVERHEAT” is shown on the multi-informa-
tion display
Stop the vehicle in a safe place and turn off the air conditioning
system.
Leave the hybrid system operating and carefully lift the hood.
Remove the engine compartment covers. ( →P. 423)
Check if the cooling fans are operating.
If the fans are operating:
Wait until the “HYBRID SYSTEM OVERHEAT” message disap-
pears and then stop the hybrid system.
If the message does not disappear, call your Lexus dealer.
If the fans are not operating:
Stop the hybrid system immediat ely and call your Lexus dealer.

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When trouble arises
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5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)After the hybrid system has cooled
down, check the power control
unit coolant level and inspect the
cooling system for leaks.
Add power control unit coolant if
necessary.
Water can be used in an emer-
gency if power control unit coolant
is unavailable. (
→P. 5 5 4 )
Have the vehicle inspected at the nearest Lexus dealer as soon as possi-
ble.
■Overheating
The following symptoms may occur when your vehicle is overheating:
●The high engine coolant temperature warning light comes on or flashes, or the
hybrid system output decreases.
●Steam comes out from the engine area.
●“HYBRID SYSTEM OVERHEAT” is displayed on the multi-information display.

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Alphabetical index
HS250h_U_75033U(Canada)
Clock (vehicles withoutnavigation system) ............................ 373
Clock (vehicles with navigation system)*
Coin holder .............................................366
Compass ................................................... 391
Condenser ..............................................430
Console box ...........................................365
Cooling system Engine overheating ............................541
Cruise control Cruise control .......................................201
Dynamic radar cruise control .....205
Cup holders ............................................ 367
Curtain shield airbags.......................... 104
Customizable features ....................... 574
Daytime running light system ........... 186
Defogger Rear window........................................260
Side mirrors ..........................................260
Dimensions............................................. 550
Dinghy towing ........................................248
Display
Dynamic radar cruise control..................................................205
Multi-information display.................169
Trip information .................................... 172
Warning message.............................. 501
Do-it-yourself maintenance .............. 416
Door courtesy lights Door courtesy lights.........................360
Wattage................................................. 558
Doors
Door glasses ........................................... 86
Door lock.................................44, 54, 57 Rear door child protector................ 58
Side doors................................................. 57
Side mirrors............................................. 83
Driver’s seat belt reminder light ..... 495
Driver’s seat position memory ........... 68
Driving
Break-in tips........................................... 137
Correct posture................................... 102
Procedures............................................. 136
Winter driving tips .............................244
Driving position memory...................... 68
Electric power steering...................... 225
Electronic key If the electronic key does not operate properly............................ 533
Emergency, in case of If the electronic key does not
operate properly............................ 533
If the engine will not start ............... 530
If the hybrid system will not start ....................................................... 530
If the 12-volt battery is discharged ........................................ 536
If the warning buzzer sounds.......492
If the warning light turns on...........492
If the warning message is displayed ..............................................501
If you have a flat tire .......................... 521
If you lose your keys ........................ 532
If you think something is wrong .................................................. 489
If your electronic key does not operate properly ................... 533
If your vehicle becomes stuck .... 545
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