2012 Lexus HS250h belt

457
4-3. Do-it-yourself maintenance
4
Maintenance and care
HS250h_U_75050U
CAUTION
■When inspecting or replacing tires
Observe the following precautions to prevent accidents. Failure to do so may cause
damage to parts of the drive train as well as dangerous handling characteristics,
which may lead to an accident resulting in death or serious injury.
●Do not mix tires of different makes, models or tread patterns. Also, do not mix
tires of remarkably different treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix differently constructed tires (radial, bias-belted or bias-ply tires).
●Do not mix summer, all season and snow tires.
●Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously.
■When initializing the tire pressure warning system
Do not operate the tire pressure warning reset switch without first adjusting the tire
inflation pressure to the specified level. Otherwise, the tire pressure warning light
may not come on even if the tire inflation pressure is low, or it may come on when
the tire inflation pressure is actually normal.

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4-3. Do-it-yourself maintenance
HS250h_U_75050UDriver’s side instrument panel
FuseAmpereCircuit
1TA I L10 AParking lights, tail lights, license plate
lights, side maker lights, front fog lights
2PA N E L10 A
Navigation system, audio system, air
conditioning system, emergency
flashers switch, wiper de-icer switch,
seat heater switch, P position switch,
headlight cleaner switch, front pas-
senger’s seat belt reminder light,
power window switch, VSC-OFF
switch, HUD switch, AFS-OFF switch,
POWER ·ECO MODE switch, EV
mode switch, view select switch, trunk
opener switch, fuel lid opener switch,
glove box light, rear sunshade switch,
remote touch, rear view mirror switch

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4-3. Do-it-yourself maintenance
4
Maintenance and care
HS250h_U_75050U
21RR FOG7. 5 ANo circuit
22FUEL OPN7. 5 ATrunk opener switch, fuel filler door
opener switch
23OBD7. 5 AOn-board diagnosis
24PWR SEAT FL30 ADriver’s side power seat
25FR FOG15 AFront fog lights
26PWR SEAT FR30 APassenger’s side power seat
27PSB30 APre-collision seat belts system
28WELCAB30 ANo circuit
29DOOR NO.125 APower door lock system
30SEAT HTR FL10 ADriver’s side seat heater
31SEAT HTR FR10 APassenger’s side seat heater
32RAD NO.27. 5 A
Navigation system, audio system, air
conditioning system, HUD, remote
touch
33PWR OUTLET15 APo w e r o u t l e t
34ECU-ACC10 ARear view mirror, air conditioning sys-
tem, audio system, navigation system
FuseAmpereCircuit

5
When trouble arises
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5-2. Steps to take in an emergency
HS250h_U_75050U
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. 552
• Flashes: Engine is overheating. Drive carefully.
• Comes on: Engine is overheated. Stop the vehicle.
Warning lightWarning light/Details
Brake system warning light 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

5
When trouble arises
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5-2. Steps to take in an emergency
HS250h_U_75050U
Follow the correction procedures.After taking the specified steps to co rrect the suspected problem, check
that the warning light goes off.
(Flashes)
Automatic High Beam indicator light (if equipped)
Indicates a malfunction in the automatic high beam system
→ P. 1 9 6
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 1 2
Warning lightWarning light/Details

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5-2. Steps to take in an emergency
HS250h_U_75050U*
1: Open door warning buzzer:
→ P. 5 1 6
*
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 pressure
such as
• Natural causes (→ P. 5 0 8 )
• Flat tire ( →P. 5 3 2 )
Adjust the tire inflation pres-
sure to the specified level.
The light will turn off after a
few minutes. In case the light
does not turn off even if the
tire inflation pressure is
adjusted, have the system
checked by your Lexus
dealer.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pres-
sure warning system
(→ P. 509)
Have the system checked by
your Lexus dealer.
Warning lightWarning light/DetailsCorrection procedure

5
When trouble arises
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5-2. Steps to take in an emergency
HS250h_U_75050U
■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 (ECU and sensors), “AIR BAG ON” indicator light, “AIR
BAG OFF” indicator light, front passenger’s seat belt buckle switch, seat belt pre-
tensioner assemblies, inflators, interconnecting wiring and power sources. (→P.
109)
■Front passenger detection sensor, passen ger 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.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage temporarily
drops, the electric power steering system warning light may come on and the warn-
ing buzzer may sound.
■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.

5
When trouble arises
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5-2. Steps to take in an emergency
HS250h_U_75050U
■If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking 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 8 4 )
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.
●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.