2011 Lexus HS250h engine overheat

142
2-1. Driving procedures
CAUTION
●Do not select shift position R when the vehicle is rolling forward, do not select D
when moving in reverse, and do not press the P position switch before the vehicle
stops fully. Doing so will cause the buzzer to sound and the shift position to
change to N. In addition, excessive forc e will be applied to the powertrain and
damage may result.
●Do not change the shift position to N while the vehicle is moving.
Doing so may cause insufficient engine braking, resulting in an accident.
●Do not turn the hybrid system off while driving.
The power steering and brake actuator will not operate properly if the hybrid sys-
tem is off.
●Use engine braking (shift position B) to maintain a safe speed when driving down
a steep hill.
Using the brakes continuously may cause the brakes to overheat and lose effec-
tiveness. ( P. 1 5 5 )
●Do not adjust the positions of the steering wheel, the seat, or the inside or outside
rear view mirrors while driving.
Doing so may result in a loss of vehicle control that can cause accidents, resulting
in death or serious injury.
●Always check that all passengers' arms, heads or other parts of their body are not
outside the vehicle, as this may result in death or serious injury.
●Do not drive in excess of the speed limit. Even if the legal speed limit permits it, do
not drive over 85 mph (140 km/h) unless your vehicle has high-speed capability
tires. Driving over 85 mph (140 km/h) may result in tire failure, loss of control and
possible injury. Be sure to consult a tire dealer to determine whether the tires on
your vehicle are high-speed capability tires or not before driving at such speeds.
■When driving on slippery road surfaces
●Sudden braking, acceleration and steer ing may cause tire slippage and reduce
your ability to control the vehi cle, resulting in an accident.
●Abrupt changes from shift position D to B and rapid changes in the engine speed
could cause the vehicle to skid, resulting in an accident.
●After driving through a pudd le, lightly depress the brake pedal to make sure that
the brakes are functioning properly. Wet brake pads may prevent the brakes from
functioning properly. If the brakes on on ly one side are wet and not functioning
properly, steering control may be af fected, resulting in an accident.

143
2-1. Driving procedures
2
When driving
CAUTION
■When changing the shift position
Be careful not to change the shift position with the accelerator pedal depressed.
Changing the shift position to any positions other than P or N may cause the vehicle
to accelerate abruptly, causing an accident and resulting in death or serious injury.
■If you hear a squealing or scraping no ise (brake pad wear limit indicators)
Have your Lexus dealer check and replac e the brake pads as soon as possible.
Rotor damage may result if the pa ds are not replaced when needed.
It is dangerous to drive the vehicle when the wear limits of the brake pads and/or
those of the brake discs are exceeded.
■When the vehicle is stopped
●Do not depress the accelerator pedal unnecessarily.
If the vehicle is in any shift position other than P or N, the vehicle may accelerate
suddenly and unexpectedly , causing an accident.
●Do not leave the vehicle with the hybrid system on for a long time.
If such a situation cannot be avoided, park the vehicle in an open space and
check that exhaust fumes do no t enter the vehicle interior.
●In order to prevent accidents due to the vehicle rolling away, always keep
depressing the brake pedal while the “READY” indicator is on. Apply the parking
brake as necessary.
●If the vehicle is stopped on an incline, in order to prevent accidents caused by the
vehicle rolling forward or backward, always depress the brake pedal and securely
apply the parking brake as needed.
●Avoid revving or racing the engine.
Running the engine at high speed while the vehicle is stopped may cause the
exhaust system to overheat, which could result in a fire if combustible material is
nearby.
■When the vehicle is parked
●Do not leave glasses, cigarette lighters, spray cans, or soft drink cans in the vehi-
cle when it is in the sun.
Doing so may result in the following:
• Gas may leak from a cigarette lighter or spray can, and may lead to a fire.
• The temperature inside the vehicle may cause the plastic lenses and plastic material of glasses to deform or crack.

167
2-2. Instrument cluster
2
When driving
NOTICE
■To prevent damage to the hybrid system and its components
A high engine coolant temperature warning light (P. 498) is installed instead of
an engine coolant temperature gauge. If the high engine coolant temperature
warning light illuminates or flashes, the vehicle may be overheating. Immediately
stop the vehicle in a safe area ( P. 5 4 8 ) .

5
When trouble arises
499
5-2. Steps to take in an emergency
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 8
• 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 lamp
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The hybrid transmission control system
SRS warning lightIndicates 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
513
5-2. Steps to take in an emergency
(U.S.A. only)
Indicates that the engine
oil should be changedComes on approxi-
mately 5000 miles
(8000 km) after the
engine oil is changed
(and the oil maintenance
data has been reset)
Check and change the
engine oil.
Indicates that the tire
inflation pressure is lowCheck the tire inflation
pressure, and adjust to the
appropriate level.
(If equipped)
Indicates that the pre-
collision system is not
currently functional
because the grille or the
sensor is dirty.
This message also
appears when the pre-
collision system is not
functional due to over-
heating.
Check the grille and the
sensor and clean them if
they are dirty.In case of overheating,
the system will become
functional once the sys-
tem cools down.
(If equipped)
Indicates that intuitive
parking assist sensor is
dirty or covered with ice
A buzzer also sounds.
The site of the malfunc-
tion and the vehicle
image are flashing.
Clean the sensor.
Wa r n i n g m e s s a g eDetailsCorrection procedure

548
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 and turn off the air conditioning
system.
Check to see if steam is coming out from the engine area.
If you see steam:
Stop the hybrid system. Carefully lift 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.
Check to see if the cooling fans are operating.
If the fans are operating:
Wait until the high engine coolant temperature warning light goes
off 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 SYSTEM OVERHEAT” is sh own on the multi-information
display:
The power control unit may be overheating.
Follow the correction procedure as described below.

5
When trouble arises
549
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.
If the engine compartment cover
needs to be removed. (P. 4 2 9 )
Add engine coolant if necessary.
Water can be used in an emer-
gency if engine coolant is unavail-
able. ( P. 5 6 0 )
Have the vehicle inspected at the ne arest Lexus dealer as soon as possi-
ble.
■ If “HYBRID SYSTEM OVERHEAT” is shown on the multi-informa-
tion display
Stop the vehicle in a safe place and turn off the air conditioning
system.
Leave the hybrid system operating and carefully lift the hood.
Check if the cooling fans are operating.
If the fans are operating:
Wait until the “HYBRID SYSTEM OVERHEAT” 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.

550
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.
If the engine compartment cover
needs to be removed. (P. 4 2 9 )
Add power control unit coolant if
necessary.
Water can be used in an emer-
gency if power control unit coolant
is unavailable. ( P. 5 6 0 )
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.