Brake Lexus HS250h 2010 Repair Manual

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When trouble arises
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5-1. Essential information
HS250h_U_75033U(Canada)
■Before emergency towingTurn the “POWER” switch to ON mode. ( →P. 1 4 6 )
Do not turn the “POWER” switch to ACCESSORY mode.
Release the parking brake.
Change the shift position to N.
When the “POWER” switch is in ACCESSORY mode, the shift position
cannot be changed to N.
■Emergency towing eyelet location
→ P. 5 2 1
CAUTION
■Caution while towing
●Use extreme caution when towing the vehicle.
Avoid sudden starts or erratic driving maneuvers which place excessive stress on
the emergency towing eyelets and the cables or chains. Always use caution for
the surroundings and other vehicles while towing.
●Do not turn off the power switch.
This may lead to accidents as the parking lock will be engaged.
●If the hybrid system is off, the power assist for the brakes and steering will not
function, making steering and braking more difficult.
■Installing towing eyelets to the vehicle
Make sure that the towing eyelets are installed securely.
If not securely installed, the towing eyelets may come loose during towing. This may
lead to accidents that cause serious injury or even death.

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When trouble arises
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5-1. Essential information
HS250h_U_75033U(Canada)
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 vehicle
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● High engine coolant temperature warning light flashes or comes
on
■ Audible symptoms
● 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
■ Operational symptoms
● Engine missing, stumbling or running rough
● 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

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5-1. Essential information
HS250h_U_75033U(Canada)
Event data recorder
In a crash or a near crash eventThe SRS airbag sensor assembly cont ains 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 brake pedal was applied or not
● Ve h i c l e s p e e d
● To what extent the accelerator pedal was depressed
● Hybrid transmission shift position
● Whether the driver and front passenger wore seat belts or not
● Driver's seat position
● SRS airbag deployment data
● SRS airbag system diagnostic data
● Front passenger’s occupant classification
The information above is intended to be used for the purpose of improv-
ing vehicle safety performance. Unlike general data 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 useful for troubleshooting, there is an event data
recorder (EDR) that records data in a crash or near crash event.

492
HS250h_U_75033U(Canada)
5-2. Steps to take in an emergency
If a warning light turns on or a warning buzzer sounds...
Stop the vehicle immediately. Continuing to drive the vehicle may be dangerous.
The following warning indicates a possible problem in the brake system.
Immediately stop the vehicle in a safe place and contact your Lexus
dealer.
*: Brake system warning buzzer
When there is a possible problem that could affect braking performance, the
warning light will come on and a warning buzzer will sound.
Parking brake engaged warning buzzer
→ P. 5 0 5
Stop the vehicl e immediately.
The following warning indicates the possibility of damage to the vehicle
that may lead to an accident. Immediately stop the vehicle in a safe place
and contact your Lexus dealer.
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Brake system warning li ght and warning buzzer*
(red indicator)
•Low brake fluid
• Malfunction in the brake system This light also comes on when the parking brake is not
released. If the light turns off after the parking brake is fully
released the system is operating normally.
Warning lightWarning light/Details
Charging system warning lightIndicates a malfunction in the vehicle’s charging system
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 nec-
essarily indicate a malfunction in the system. However, if this continues to
occur, have the vehicle inspected by your Lexus dealer.

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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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5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
CAUTION
●Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you could
lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold
and inflated to the inflation pressure recommended by the vehicle manufacturer on
the vehicle placard or tire inflation pressure label (tire and load information label).
(If your vehicle has tires of a different size than the size indicated on the vehicle
placard or tire inflation pressure label [tire and load information label], you should
determine the proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle has been equipped with a tire pressure
monitoring system (TPMS-tire pressure warning system) that illuminates a low tire
pressure telltale (tire pressure warning light) when one or more of your tires is sig-
nificantly under-inflated. Accordingly, when the low tire pressure telltale (tire pres-
sure warning light) illuminates, you should stop and check your tires as soon as
possible, and inflate them to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat and can lead to tire failure. Under-inflation
also reduces fuel efficiency and tire tread life, and may affect the vehicle’s handling
and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a substitute for
proper tire maintenance, and it is the driver’s responsibility to maintain correct tire
pressure, even if under-inflation has not reached the level to trigger illumination of
the TPMS low tire pressure telltale (tire pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system)
malfunction indicator to indicate when the system is not operating properly. The
TPMS (tire pressure warning system) malfunction indicator is combined with the
low tire pressure telltale (tire pressure warning light). When the system detects a
malfunction, the telltale will flash for approximately one minute and then remain
continuously illuminated. This sequence will continue upon subsequent vehicle
start-ups as long as the malfunction exists. When the malfunction indicator is illumi-
nated, the system may not be able to detect or signal low tire pressure as intended.

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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.A buzzer sounds and a warning message is shown on the multi-informa-
tion display. Failure 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.
Wa r n i n g m e s s a g eDetails
Indicates a malfunction in the P position control A buzzer also sounds.
In this situation, there is a possibility that the parking
lock mechanism will not work.
When parking, park the vehi cle on a flat surface and
apply the parking brake securely. Also, it may not be
possible to turn the “POWER” switch off. If this hap-
pens, applying the parking brake will enable the
switch to be turned off.
(Flashes)
(If equipped)
Indicates a malfunction in the LED headlight system A buzzer also sounds.
(Flashes)
(If equipped)
Indicates a malfunction in the pre-collision system A buzzer also sounds.

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5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
(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 in dicate 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

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5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
(Flashes)
(If equipped)
Indicates that the radar
cruise control sensor is
dirty or covered with ice A buzzer also sounds.
Clean the sensor.
(Flashes)
(If equipped)
Indicates that the radar
cruise control system is
unable to judge vehicle-
to-vehicle distance A buzzer also sounds.• Switch driving mode to normal.
• Stop the wiper or change the mode to
auto, low or intermittent.
(Flashes)
(If equipped)
Alerts the driver that
there is a high possibility
of collision or the pre-col-
lision brake has activated A buzzer also sounds.
At the same time,
will appear on
the head-up display too
(the image flashes).
Slow the vehicle by apply-
ing the brakes.
Wa r n i n g m e s s a g eDetailsCorrection procedure

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5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
(Flashes)
(If equipped)
Indicates that your vehi-
cle is nearing the vehicle
ahead (in radar cruise
mode)
A buzzer also sounds.
At the same time,
will appear on
the head-up display (the
image flashes).
Slow the vehicle by apply-
ing the brakes.
(Flashes)
(If equipped)
Indicates a malfunction in
the LKA system A buzzer also sounds.Restart the hybrid system
and then reactivate the
lane keeping assist system.
Indicates that the LKA is
suspendedA buzzer also sounds.
•The camera sensor temperature is higher
than the operation tem-
perature range.
• The power steering
system operation is
restricted.
Reactivate the lane keep-
ing assist system.
Wa r n i n g m e s s a g eDetailsCorrection procedure