Check hybrid system Lexus HS250h 2010 Hybrid system / LEXUS 2010 HS250H (OM75006U) Owner's Manual

429
4-3. Do-it-yourself maintenance
4
Maintenance and care
Power control unit coolant reservoirReservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. (P. 5 5 2 )
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a s
imilar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.: “Toyota Super Long Life Coolant” is a
mixture of 50% coolant and 50%
deionized water. (Minimum temperature: -31 F [-35C])
Canada: “Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% d
eionized water. (Minimum temperature: -44 F [-42 C])
For more details about coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiators, hoses, engine/power control unit coolant reservoir
ca
ps, drain cock and water pump. 
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in
the coo
ling systems.

430
4-3. Do-it-yourself maintenance
Radiator and condenser
Check the radiator and condenser and clear away any foreign objects. 
If either of the above parts is extremely dir
ty or you are not sure of their
condition, have your vehicle inspected by your Lexus dealer.
CAUTION
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps. 
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing burns or other injuries.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water
and antifreeze must be used to provide proper lubrication, corrosion protection
and cooling. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
CAUTION
■When the hybrid system is hot
Do not touch the radiators or condense r as they may be hot and cause burns.

510
5-2. Steps to take in an emergency
Alerts the driver that the
vehicle is out of the lanes
(while the LKA system is
operating).A buzzer also sounds.
The lane markings and/
or the steering wheel
marking flash.
At the same time,
will appear on
the head-up display (the
image flashes).
Check the road condi-
tions and drive the vehicle
at a safe speed.
Indicates that the hybrid
system has overheated A buzzer also sounds.Stop and check.
( P. 5 4 1 )
(Flashes)
Indicates that the traction
battery is low
The warning buzzer
sounds intermittently.
When stopping the vehi-
cle for a long period of
time, change the shift
position to P. The battery
cannot be charged with
the shift position in N.
(Flashes)
Indicates that the traction
battery power has
dropped because a long
period of time has
elapsed after changing
the shift position to NThe warning buzzer
sounds continuously.
Restart the hybrid system
when starting the vehicle.
Wa r n i n g m e s s a g eDetailsCorrection procedure

5
When trouble arises
513
5-2. Steps to take in an emergency
Have the malfunction repaired immediately
After taking the specified steps to correct the suspected problem, check
that the warning message and light go off.
Interior buzzerExterior buzzerWa r n i n g m e s s a g eDetailsCorrection
procedure
Once
(Flashes)
The electronic key
is not detected
when an attempt
is made to start
the hybrid system.Start the hybrid
system with the
electronic key
present.
Once3 times
(Flashes)
The electronic key
was carried out-
side the vehicle
and a door other
than the driver's
door was opened
and closed while
the “POWER”
switch was in a
mode other than
off.
Bring the elec-
tronic key back
into the vehicle.
The electronic key
was carried out-
side the vehicle
and the driver’s
door was opened
and closed while
the shift position P
was selected with-
out turning off the
“POWER” switch.
Tu r n t h e
“POWER” switch
off or bring the
electronic key
back into the vehi-
cle.

528
5-2. Steps to take in an emergency
CAUTION
■Using the tire jack
Improper use of the tire jack may cause the vehicle to suddenly fall off the jack,
leading to death or serious injury.
●Do not use the tire jack for any purpose other than replacing tires or installing and
removing tire chains.
●Only use the tire jack that comes with this vehicle for replacing a flat tire.
Do not use it on other vehicles, and do no t use other tire jacks for replacing tires
on this vehicle.
●Always check that the tire jack is securely set to the jack point.
●Do not put any part of your body under th e vehicle while it is supported by the
jack.
●Do not start or run the hybrid system while your vehicle is supported by the jack.
●Do not raise the vehicle while someone is inside.
●When raising the vehicle, do not put an object on or under the jack.
●Do not raise the vehicle to a height greate r than that required to replace the tire.
●Use a jack stand if it is necessary to get under the vehicle.
Take particular care when lowering the vehicle to ensure that no one working on or
near the vehicle may be injured.
■Replacing a flat tire
Observe the following precautions to reduce the risk of death or serious injury:
●Do not touch the disc wheels or the area around the brakes immediately after the
vehicle has been driven.
After the vehicle has been driven the disc wheels and the area around the brakes
will be extremely hot. Touching these areas with hands, feet or other body parts
while changing a tire, etc. may result in burns.
●Never use oil or grease on the wheel bolts or wheel nuts. 
Oil and grease may cause the wheel nuts to be excessively tightened, leading to
bolt or disc wheel damage. In addition, the oil or grease can cause the wheel nuts
to loosen and the wheel may fall off, causing a serious accident. Remove any oil or
grease from the wheel bolts or wheel nuts.

530
5-2. Steps to take in an emergency
If the hybrid system will not start
Reasons for the hybrid system not starting vary depending on the situation.
Check the following and perform the appropriate procedure:
■The hybrid system will not start even though the correct starting
procedure is being followed. ( P. 1 4 7 )
One of the following may be the cause of the problem:
● The electr
onic key may not be functioning properly.* (P. 5 3 3 )
● Ther
e may not be sufficient fuel in the vehicle’s tank. 
Refuel the vehicle.
● Ther
e may be a malfunction in the immobilizer system.* (P. 9 6 )
● Ther
e may be a malfunction in the P position control system.* 
( P. 1 5 0 , 502 )
● The hybrid s
ystem may be malfunc tioning due to an electrical
problem such as an open circuit or a blown fuse. However,
depending on the type of malfunc tion, an interim measure is avail-
able to start the hybrid system. ( P. 4 5 5)
*: It may not be possible to shift out of the P position.
■The interior lights and headlights are dim, or the horn does not
sound or sounds at a low volume.
One of the following may be the cause of the problem:
● The 12-
volt battery may be discharged. (P. 5 3 6 )
● The 12-
volt battery terminal co nnections may be loose or cor-
roded.

5
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.

542
5-2. Steps to take in an emergency
After the hybrid system has cooled
down sufficiently, check the engine
coolant level and inspect the cool-
ing system for leaks.
Add engine coolant if necessary.
Water can be used in an emer -
gency if engine coolant is unavail -
able. ( P. 5 5 2 )
Have the vehicle inspected at the ne arest Lexus dealer as soon as possi-
ble.
■ If “HYBRID S
YSTEM OVERHEAT” is shown on the multi-informa -
tion display
Stop the vehicle in a safe place an d turn of
f the air conditioning
system.
Leave the hybrid system operating and carefully lift the hood.
Remove the engine compartment covers. ( P. 4 2 3 )
Check if the cooling fans are operating.
If the fans are operating: 
Wait until the “HYBRID SYST EM O
VERHEAT” message disap-
pears and then stop the hybrid system. 
If the message does not disappear, call your Lexus dealer.
If the fans are not operating: 
Stop the hybrid system immediately and call your Lexus dealer.

5
When trouble arises
543
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.

544
5-2. Steps to take in an emergency
CAUTION
■To prevent an accident or injury when inspecting under the hood of your vehicle
●If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartm ent may be very hot, causing serious
injuries such as burns.
●Check that the indicator on the “POWER ” switch and the READY indicator are
off.
●For vehicles with a hybrid system, there are times when the gasoline engine auto-
matically starts to run or the cooling fans suddenly start to operate. Do not touch
or approach the rotating parts of the belt or fans. Doing so may lead to fingers,
clothes or tools getting caught, resulting in injury.
●Do not loosen the coolant reservoir cap while the hybrid system and radiator are
hot. 
Serious injuries, such as burns, may resu lt from hot coolant and steam released
under pressure.
NOTICE
■When adding engine/power control unit coolant
Wait until the hybrid system has cooled down before adding engine/power control
unit coolant. 
When adding coolant, do so slowly. Adding cool coolant to a hot hybrid system too
quickly can cause damage to the hybrid system.