2010 Lexus HS250h check engine light

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4-2. MaintenanceMaintenance 
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 prop erly ............... 533
If the vehicle 12-volt battery 
is discharged ............................... 536
If your vehicle overheats ............ 541
If the vehicle becomes 
stuck................................................ 545
5When trouble arises

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2-1. Driving procedures
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When driving
CAUTION
■When starting the vehicle
Always keep your foot on the brake pedal while stopped with the hybrid system
operating. 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
pedals 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 that could result in
death or serious injury.
• When backing up, you may twist your body around, leading to a difficulty in
operating the pedals. Make sure to operate the pedals properly.
• Make sure to keep a correct driving posture even when moving the vehicle only slightly. This allows you to depress the brake and accelerator pedals
properly.
• Depress the brake pedal using your right foot. Depressing the brake pedal using your left foot may delay response in an emergency, resulting in an acci-
dent.
●The driver should pay extra attention to pedestrians when the vehicle is powered
only by the electric motor (traction motor). Because there is no engine noise, the
pedestrians may misjudge the vehicle’s movement.
●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.
●Do not let the vehicle roll backward whil e a forward driving position is selected,
or roll forward while R is selected. 
Doing so may result in an acci dent or damage to the vehicle.
●If the smell of exhaust is noticed inside the vehicle, open the windows and check
that the trunk is closed. Large amounts of exhaust in the vehicle can cause driver
drowsiness and an accident, resulting in death or a serious health hazard. Have
the vehicle inspected by your Lexus dealer immediately.
●Do not shift the shift position 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 position to R while the vehicle is moving forward. 
Doing so can damage the transmission and may result in a loss of vehicle control.

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2-1. Driving procedures
CAUTION
●Do not shift the shift position to D while the vehicle is moving backward.
Doing so can damage the transmission and may result in a loss of vehicle control.
●Moving the shift position to N while the vehicle is moving will disengage the
hybrid system. Engine braking is not avai lable with the hybrid system disengaged.
●During normal driving, do not turn off the hybrid system. Turning the hybrid sys-
tem off while driving will not cause loss of steering or braking control, but the
power assist to these systems will be lost. Th is will make it more difficult to steer
and brake, so you should pull over and stop the vehicle as soon as it is safe to do
so. However, in the event of an emergency, such as if it becomes impossible to
stop the vehicle in the normal way: P. 4 9 2
●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, he ads 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, accelerati on and steering may cause tire slippage and reduce
your ability to control the vehi cle, 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 on ly one side are wet and not functioning
properly, steering control may be af fected, resulting in an accident.

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2-1. Driving procedures
2
When driving
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 no ise (brake pad wear limit indicators)
Have your Lexus dealer check and replac e the brake pads as soon as possible. 
Rotor damage may result if the pa ds 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 no t 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, cigarett e 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 plastic material of glasses to deform or crack.

Maintenance and care4
401
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

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4-3. Do-it-yourself maintenance
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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

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When trouble arises
541
5-2. Steps to take in an emergency
If your vehicle overheats
Correction procedures
■If the engine coolant temperature warning light comes on or flashes
Stop the vehicle in a safe place an d turn of
f the air conditioning
system.
Check to see if steam is coming out from the engine area.
If you see steam: 
Stop the hybrid system. Carefu lly lif
t 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. 4 2 3 )
Check to see if the cooling fans are operating.
If the fans are operating: 
Wait until the high engine coolant temperature warning light goes
of
f 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 S
YSTEM OVERHEAT” is sh own on the multi-information
display: 
The power control unit may be overheating.
Follow the correction procedure as described below.

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When trouble arises
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5-2. Steps to take in an emergency
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
nec
essary.
Water can be used in an emer -
gency if power control unit coolant
is una
vailable. ( P. 5 5 2 )
Have the vehicle inspected at the ne arest Lexus dealer as soon as possi-
ble.
■Overheating
The following symptoms may occur wh en
your vehicle is overheating:
●The high engine coolant temperature warn ing 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.