brakes Lexus HS250h 2010 Hybrid System / LEXUS 2010 HS250H OWNERS MANUAL (OM75006U)

37
1
1-1. Hybrid system
Before driving
Hybrid vehicle driving tips
For economical and ecological driving, pay attention to the following
points:
■ Using Eco Mode
When using Eco mode, the torque corresponding to the accelerator pedal
depression amount can be generated more smoothly than it is in normal
conditions. In addition, the operation of the air conditioning system will be
minimized, improving the fuel economy. 
( P. 1 5 5 )
■Use of Hybrid System Indicator
The environmentally-friendly driving is possible by keeping the indicate of
Hybrid System Indicator within Eco area. ( P. 1 6 4 )
■When braking the vehicle
Make sure to operate the brakes ge ntly and in good time. A greater
amount of electrical energy can be retained when slowing down.
■ Delays
Repeated acceleration and deceleration, as well as long waits at traffic
lights, will lead to bad fuel consumpt ion. Check traffic reports before leav -
ing and avoid delays as much as possible. When encountering a delay,
gentl
y release the brake pedal to allow the vehicle to move forward slightly
while avoiding overuse of the accelerato r pedal. Doing so can help control
excessive gasoline consumption.
■ Highway driving
Control your speed and keep at a constant speed. Also, before stopping at
a toll booth or similar, allow plenty of time to release the accelerator and
gently apply the brakes. A greater amount of electrical energy can be
retained when slowing down.

137
2-1. Driving procedures
2
When driving
Starting off on a steep uphill
Make sure that the parking brake is set secu rely, and then select
shift position D. 
Check that the shift position indicator shows D.
Gently depress the accelerator pedal.
Release the parking brake.
■Driving in the rain
●Drive carefully when it is raining, becaus e visibility will be reduced, the windows
may become fogged-up, and the road will be slippery.
●Drive carefully when it starts to rain, be cause the road surface will be especially
slippery.
●Refrain from high speeds when driving on an expressway in the rain, because
there may be a layer of wate r between the tires and the road surface, preventing
the steering and brakes from operating properly.
■Breaking in your new Lexus
To extend the life of the vehicle, observing the following precautions is recom -
mended:
●For the first 186 miles (300 km): 
Avoid sudden stops.
●For the first 994 miles (1600 km):
• Do not drive at extremely high speeds.
• Avoid sudden acceleration.
• Do not drive at a constant speed for extended periods.
■Drum-in-disc type parking brake system
Your vehicle has a drum-in-disc type parking brake system. This type of brake sys -
tem needs bedding-down of the brake shoes perio
dically or whenever the parking
brake shoes and/or drum are replaced. Have your Lexus dealer perform the bed-
ding down operation.

140
2-1. Driving procedures
CAUTION
●Do not shift the shift position to D while the vehicle is moving backward.
Doing so can damage the transmission and may result in a loss of vehicle control.
●Moving the shift position to N while the vehicle is moving will disengage the
hybrid system. Engine braking is not avai lable with the hybrid system disengaged.
●During normal driving, do not turn off the hybrid system. Turning the hybrid sys-
tem off while driving will not cause loss of steering or braking control, but the
power assist to these systems will be lost. Th is will make it more difficult to steer
and brake, so you should pull over and stop the vehicle as soon as it is safe to do
so. However, in the event of an emergency, such as if it becomes impossible to
stop the vehicle in the normal way: P. 4 9 2
●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 3 )
●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, he ads 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, accelerati on and steering 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 puddle , 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 taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, if you accidentally move the shift
lever or depress the accelerator pedal, this could cause an accident or fire due to
hybrid system overheating. Additionally, if the vehicle is parked in a poorly venti-
lated area, exhaust gases may collect and enter the vehicle, leading to death or a
serious health hazard.
■When braking
●When the brakes are wet, drive more cautiously. 
Braking distance increases when the brakes are wet, and this may cause one side
of the vehicle to brake differently than the other side. Also, the parking brake may
not securely hold the vehicle.
●If the power brake assist function does not operate, do not follow other vehicles
closely and avoid downhill or sharp turns that require braking. 
In this case, braking is still possible, but it will require more force on the pedal than
usual. Braking distance may also increase.
●The brake system consists of 2 individual hydraulic systems; if one of the systems
fails, the others will still operate. In th is case, the brake pedal should be depressed
more firmly than usual and the braking distance will increase. If this happens, do
not continue to drive the vehicle. If the brake system warning light (red indicator)
comes on while driving, immediately stop the vehicle in a safe place and contact
your Lexus dealer.
NOTICE
■When driving the vehicle
Do not use the accelerator pedal or depress the accelerator and brake pedals at
the same time to hold the vehicle on a hill.
■When parking the vehicle
Be sure to firmly apply the parking brake and set the shift position to P. Failure to do
so may cause the vehicle to move or the vehicle may accelerate suddenly if the
accelerator pedal is accidentally depressed.

202
2-4. Using other driving systems
Accelerate or decelerate to the
desired speed, and push the
lever down to set the speed.
“SET” indicator will come on.
■Adjusting the set speed
Increases the speed
Decreases the speed
Hold the lever until the desired
speed setting is obtained.
Fine adjustment of the set speed
can be made b
y lightly pushing
the lever up or down and releas -
ing it.
■ Canceling and resuming the constant speed control
Pulling the lever toward you
cancels the constant speed
contr
ol.
The speed setting is also can -
celed when the brakes are
applied.
Pushing the lever up resumes
the constant speed control.

208
2-4. Using other driving systems
■Changing the vehicle-to-vehicle distance
Pressing the button changes the
vehicle-to-vehicle distance as
follows:
Long
Medium
Short
The vehicle-to-vehicle distance
is set automatically to long
mode when the “POWER”
switch is turned to ON mode.
If a vehicle is running ahead of
y
ou, the preceding vehicle mark
will also be displayed.
■ Canceling and resuming the constant speed control
Pulling the lever toward you
cancels the cruise control.
The speed setting is also can -
celed when the brakes are
applied.
Pushing the lever up resumes
the cruise control and returns
v

ehicle speed to the set
speed.
Resuming is available when the
vehicle speed is more than
approximately 25 mph (40 km/
h).
Preceding vehicle mark

209
2-4. Using other driving systems
2
When driving
Driving in vehicle-to-vehicle distance control mode
This mode employs a sensor to detect the presence of vehicles up to
approximately 400 ft. (120 m) ahead and to judge the distance between
your vehicle and those the vehicle ahead of you.
Note that vehicle-to-vehicle distance will close in when traveling on long
downhill slopes.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-vehi-
cle distance can also be set by operating the vehicle-to-vehicle distance con -
trol.
Example of deceleration cruising
When the vehicle ahead is driving slower than the set speed
When a vehicle is detected running ahead of you, the system automatically
decelerates your vehicle. When a grea ter reduction in vehicle speed is nec-
essary, the system applies the brakes. A warning tone warns you when the
s
ystem cannot decelerate sufficiently to prevent your vehicle from closing in
on the vehicle ahead.

210
2-4. Using other driving systems
Example of follow-up cruising 
When following a vehicle driving slower than the set speed
The system continues follow-up cruising while adjusting for changes in the
speed of the vehicle ahead in order to maintain the vehicle-to-vehicle dis -
tance set by the driver.
Example of acceleration 
When there are no longer any vehicles ahead driving slo
wer than the
set speed.
The system accelerates until the set speed is reached. The system then
returns to constant speed cruising.
Approach warning
When your vehicle is too close to a vehicle ahead, and sufficient auto-
matic deceleration via th e cruise contr
ol is not possible, the display will
flash and the buzzer will so und to alert the driver. An example of this
would be if another driver cuts in fron t of you while you are following a
vehicle. Apply the brakes to ensure an appropriate vehicle-to-vehicle dis -
tance.

214
2-4. Using other driving systems
■Certification
For vehicles sold in the U.S.A.
FCC ID: HYQDNMWR004
This device complies with Part 15 of the FCC Rules. Operation is subject to the fol-
lowing two conditions: (1) this device may not cause harmful interference, and (2)
this device must accept any interference received, including interference that may
cause undesired operation.
FCC WARNING
Changes or modifications not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
Radio frequency radiation exposure Information:
This equipment complies with FCC radiatio n exposure limits set forth for an uncon-
trolled environment.
This equipment should be installed and op erated with minimum distance of 20 cm
between the radiator (antenna) and your body.
This transmitter must not be co-located or operating in conjunction with any other
antenna or transmitter.
CAUTION
■Before using dynamic radar cruise control
Do not overly rely on vehicl e-to-vehicle distance control. 
Be aware of the set speed. If automatic deceleration/acceleration is not appropri-
ate, adjust the vehicle speed, as well as the distance between your vehicle and vehi-
cles ahead by applying the brakes etc.
■Cautions regarding the driving assist systems
Observe the following precautions. 
Failure to do so may cause an accident resulting in death or serious injury.
●Assisting the driver to measure following distance 
The dynamic radar cruise control is only in tended to help the driver in determin-
ing the following distance between the driver’s own vehicle and a designated
vehicle traveling ahead. It is not a mechanism that allows careless or inattentive
driving, and it is not a system that can assist the driver in low-visibility conditions. It
is still necessary for driver to pay clos e attention to the vehicle’s surroundings.

215
2-4. Using other driving systems
2
When driving
CAUTION
●Assisting the driver to judge proper following distance 
The dynamic radar cruise control determ ines whether the following distance
between the driver’s own vehicle and a designated vehicle travelling ahead is
appropriate or not. It is not capable of making any other type of judgement.
Therefore, it is absolutely necessary for the driver to remain vigilant and to deter-
mine whether or not there is a possibil ity of danger in any given situation.
●Assisting the driver to operate the vehicle 
The dynamic radar cruise control has no capability to prevent or avoid a collision
with a vehicle travelling ahead. Therefore, if there is ever any danger, the driver
must take immediate and direct control of the vehicle and act appropriately in
order to ensure the safety of all involved.
■To avoid inadvertent cruise control activation
Switch the cruise control off using the “ON-OFF” button when not in use.
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise contro l in any of the following situations.
Doing so may result in inappropriate sp eed control and could cause an accident
resulting in death or serious injury.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as thos e covered with rain, ice and snow
●On steep downhills, or where there are sudden changes between sharp up and
down gradients. 
Vehicle speed may exceed the set speed when driving down a steep hill.
●At entrances to expressways
●When weather conditions are bad enough that they may prevent the sensors
from functioning correctly (fog, sn ow, sandstorm, heavy rain, etc.)
●When an approach warning buzzer is heard often
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are in
front of you. As the sensor may not be able to correctly detect these types of vehi-
cles, the approach warning (P. 210) will not be activated, and a fatal or serious
accident may result.