ECU Lexus HS250h 2010 Hybrid System / LEXUS 2010 HS250H (OM75006U) Workshop Manual

479
4-3. Do-it-yourself maintenance
4
Maintenance and care
■Lights other than the above
If any of the lights listed belo
w has burnt out, have it replaced by your
Lexus dealer.
● Headlight lo
w beams (LED headlight type)
● Side turn signal lights
● Stop
/tail lights
●T
ail lights
●R
ear side marker lights
●High mounted stoplight
● Ou
ter foot lights
■When replacing the front right headlight, fr ont turn signal lights and parking light
bulbs
■LED light bulbs
The headlight low beams (LED headlights type), side tu
rn signal lights, rear side
marker lights, stop/tail lights, tail lights and high mounted stoplight consist of a num -
ber of LEDs. If any of the LEDs burn out, take your vehicle to your Lexus dealer to
hav
e the light replaced.
Remove the securing clip and move the
washer fluid filler opening to allow easy
access to the light bulbs.
After replacing the bulbs, make sure to
secure the washer fluid filler opening with the
clip.

480
4-3. Do-it-yourself maintenance
■Condensation build-up on the inside of the lens
Contact your Lexus dealer for more information in the following situations. Tempo-
rary condensation build-up on the inside of the headlight lens does not indicate a
malfunction.
●Large drops of water have built up on the inside of the lens.
●Water has built up inside the headlight.
CAUTION
■Replacing light bulbs
●Turn off the lights. Do not attempt to replace the bulb immediately after turning
off the lights. 
The bulbs become very hot and may cause burns.
●Do not touch the glass portion of the light bulb with bare hands. Hold the bulb by
the plastic or metal portion. 
If the bulb is scratched or drop ped, it may blow out or crack.
●Fully install light bulbs and any parts used to secure them. Failur to do so may
result in heat damage, fire, or water ente ring the headlight unit. This may damage
the headlights or cause condensation to build up on the lens.
■To prevent damage or fire
Make sure bulbs are fully seated and locked.

5
When trouble arises
483
5-1. Essential information
If your vehicle needs to be towed
Before towing
The following may indicate a problem with your hybrid transmission.
Contact your Lexus dealer before towing.
● The hybrid s
ystem is operating but the vehicle will not move.
● The v
ehicle makes an abnormal sound.
Emergency towing
If a tow truck is no t available in an
emergency, your vehicle may be
temporarily towed using a cable or
chain secured to the emergency
towing eyelet(s). This should only
be attempted on hard surfaced
roads for short distances at under
18 mph (30 km/h).
A driver must be in the vehicle to
steer and operate the brakes. The
vehicle’s wheels, drive train, axles,
steering and brakes must be in
good condition.
If towing is necessary, we recommen d having your vehicle towed by your
Lexus dealer or a commercial towing service, using a lift-type truck or a
flatbed truck.

Use a safety chain system for all towing , a
nd abide by all state/provincial
and local laws.

5
When trouble arises
485
5-1. Essential information
Tighten down the towing eyelet
securely using a wheel nut wrench.
Towing with a sling-type truck
Do not tow with a sling-type truck
to prevent body damage.
Towing with a wheel-lift type truck
From the frontRelease the parking brake.

5
When trouble arises
487
5-1. Essential information
■Before emergency towingTurn the “POWER” switch to ON mode. ( P.
1 4 8 )
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
ca
nnot 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.
●Do not turn off the power switch. 
This may lead to accidents as th e 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 eyel ets may come loose during towing. This may
lead to accidents that cause serious injury or even death.

5
When trouble arises
497
5-2. Steps to take in an emergency
■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 chan ges 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 inflatio n 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.

502
5-2. Steps to take in an emergency
Have the vehicle inspected by your Lexus dealer immediately.
A buzzer sounds and a warning messa ge is shown on the multi-informa-
tion display. Failure to investigate the cause of the follo
wing 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 vehicle 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.

5
When trouble arises
517
5-2. Steps to take in an emergency
Once
(Flashes)
•When the doors were unlocked
with the
mechanical key
and then the
“POWER”
switch was
pressed, the
electronic key
could not be
detected in the
vehicle.
• The electronic key could not be
detected in the
vehicle even
after the
“POWER”
switch was
pressed two
consecutive
times.
Touch the elec-
tronic key to the
“POWER” switch
while depressing
the brake pedal.
Once
(Flashes)
An attempt was
made to start the
hybrid system
with the shift posi-
tion in N.Change the shift
position to P and
start the hybrid
system.
Interior buzzerExterior buzzerWa r n i n g m e s s a g eDetailsCorrection
procedure

522
5-2. Steps to take in an emergency
Taking out the jack and spare tire
Lift up the hook of the panel on the
trunk floor.
Secure the panel using the hook
pr
ovided.
Remove the jack after removing
the hook.

5
When trouble arises
523
5-2. Steps to take in an emergency
Take out the tool tray.
Loosen the center fastener that
secur
es the spare tire.
Replacing a flat tire
Chock the tires.
Flat tireWheel chock
positions
Front
Left-
hand sideBehind the
rear right-
hand side tire
Right-
hand sideBehind the
rear left-
hand side tire
Rear
Left-
hand sideIn front of the
front right-
hand side tire
Right-
hand sideIn front of the
front left-
hand side tire