warning Lexus HS250h 2010 Repair Manual

5
When trouble arises
489
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

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.

5
When trouble arises
493
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

494
5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
Electric power steering system warning light (warning
buzzer)Indicates a malfunction in the EPS (Electric Power Steering)
system
(Flashing)
“PCS” warning light (if equipped)Indicates a malfunction in the pre-collision system
→ P. 2 3 2
(Flashing)
“AFS OFF” indicator light (if equipped)
Indicates a malfunction in the AFS (Adaptive Front-lighting
System)
Slip indicator light
Indicates a malfunction in:
• Enhanced VSC system;
•TRAC system; or
• Hill-start assist control system
(Flashing)
“LKA” indicator light (if equipped)Indicates a malfunction in the lane keeping assist system
→ P. 2 1 7
(Flashing)
Cruise control indicator light
Indicates a malfunction in the cruise control system
→ P. 2 0 1 , 205
(Flashing)
Radar cruise control indicator light (if equipped)
Indicates a malfunction in the Dynamic radar cruise control
system →P. 2 0 5
Warning lightWarning light/Details

5
When trouble arises
495
5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
Follow the correction procedures.After taking the specified steps to co rrect the suspected problem, check
that the warning light goes off.
Warning lightWarning light/DetailsCorrection procedure
Open door warning light
(warning buzzer)
*1
Indicates that a door or the
trunk is not fully closed.
Check that all the doors and
the trunk are closed.
Low fuel level warning light
Indicates remaining fuel is
approximately 2.2 gal. (8.3
L, 1.8 Imp. gal.) or less
Refuel the vehicle.
Driver’s seat belt reminder
light (warning buzzer)
*2
Warns the driver to fasten
his/her seat belt.Fasten the seat belt.
(On the center panel)
Front passenger’s seat belt
reminder light
(warning buzzer)
*2
Warns the front passenger to
fasten his/her seat belt.
Fasten the seat belt.
Master warning light
A buzzer sounds and the
warning light comes on and
flashes to indicate that the
master warning system has
detected a malfunction.
→ P. 5 0 1

496
5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)*
1: Open door warning buzzer:
→
P. 5 0 5
*2: Driver’s and front passenger’s seat belt buzzer:
The driver’s and front passenger’s seat belt buzzer sounds to alert the driver and
front passenger that his or her seat belt is not fastened. The buzzer sounds inter-
mittently for 10 seconds after the vehicle reaches a speed of 12 mph (20 km/h).
Then, if the seat belt is still unfastened, the buzzer will sound in a different tone
for 20 more seconds.
Tire pressure warning light
When the light comes on:
Low tire inflation pressureAdjust the tire inflation pres-
sure.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pres-
sure warning system
Have the system checked by
your Lexus dealer.
■SRS warning light
This warning light system monitors the airbag sensor assembly, front airbag sensors,
side and curtain shield airbag sensors, curtain shield and rear side airbag sensors,
driver’s seat position sensor, driver’s seat belt buckle switch, front passenger occu-
pant classification system, “AIR BAG ON” indicator light, “AIR BAG OFF” indicator
light, front passenger’s seat belt buckle switch, seat belt pretensioner assemblies,
inflators, interconnecting wiring and power sources. ( →P. 106)
■Front passenger detection sensor, passeng er seat belt reminder and warning
buzzer
●If luggage is placed on the front passenger seat, the front passenger detection
sensor may cause the warning light to flash and the warning buzzer to sound
even if a passenger is not sitting in the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the
warning light may not operate properly.
Warning lightWarning light/DetailsCorrection procedure

5
When trouble arises
497
5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
■Electric power steering warning light (warning buzzer)
The electric power steering warning light comes on and the warning buzzer sounds
when the voltage is low or the voltage drops.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving trips.
If the light does not go off even after several trips, contact your Lexus dealer as soon
as possible.
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch will not turn off the tire pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural
air leaks and tire inflation pressure changes caused by temperature. In this case,
adjusting the tire inflation pressure will turn off the warning light (after a few min-
utes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with a tire pressure warning valve and trans-
mitter. If a tire goes flat, the tire pressure warning light will not turn off even though
the flat tire has been replaced with the spare tire. Replace the spare tire with the
repaired tire and adjust the tire inflation pressure. The tire pressure warning light
will go off after a few minutes.
■If the tire pressure warning system is not functioning
The tire pressure warning system will be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If tires not equipped with tire pressure warning valves and transmitters are used.
●If the ID code on the tire pressure warning valves and transmitters is not regis-
tered in the tire pressure warning computer.
●If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher.

498
5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
The tire pressure warning system may be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If electronic devices or facilities using similar radio wave frequencies are nearby.
●If a radio set at similar frequency is in use in the vehicle.
●If a window tint that affects the radio wave signals is installed.
●If there is a lot of snow or ice on the vehicle, particularly around the wheels or
wheel housings.
●If non-genuine Lexus wheels are used (Even if you use Lexus wheels, the tire
pressure warning system may not work properly with some types of tires.)
●If tire chains are used.
■If the tire pressure warning light comes on after flashing frequently for 1 minute
If the tire pressure warning light comes on after flashing frequently for 1 minute
when the “POWER” switch is turned to ON mode, have it checked by your Lexus
dealer.
■Customization that can be configured at Lexus dealer
The vehicle speed linked seat belt reminder buzzer can be disabled.
(Customizable features →P. 5 74 )
CAUTION
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
If the steering wheel becomes heavier than usual when operating, hold firmly and
operate it using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause loss of
vehicle control and result in death or serious injury.
●Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pres-
sure immediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust-
ment, it is probable that you have a flat tire. Check the tires. If a tire is flat, change
it with the spare tire and have the flat tire repaired by the nearest Lexus dealer.

5
When trouble arises
499
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.

500
5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
CAUTION
TPMS (tire pressure warning system) malfunctions may occur for a variety of rea-
sons, including the installation of replacement or alternate tires or wheels on the
vehicle that prevent the TPMS (tire pressure warning system) from functioning
properly. Always check the TPMS (tire pressure warning system) malfunction tell-
tale after replacing one or more tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow the TPMS (tire pressure warning
system) to continue to function properly.
NOTICE
■Precaution when installing a different tire
When a tire of a different specification or maker is installed, the tire pressure warn-
ing system may not operate properly.