brakes Lexus IS250 2010 Owner's Manual

126
2-1. Driving procedures
IS350/250_U
■Starting off on a hill (vehicles with an automatic transmission)
Hill-start assist control will operate. (→P. 1 9 6 )
■Driving in the rain
●Drive carefully when it is raining, because visibility will be reduced, the windows
may become fogged-up, and the road will be slippery.
●Drive carefully when it starts to rain, because 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 water 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, the following precautions are recommended to
observe:
●For the first 186 miles (300 km):
Avoid sudden stops.
●For the first 621 miles (1000 km):
• Do not drive at extremely high speeds.
• Avoid sudden acceleration.
• Do not drive continuously in the low gears.
• 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 periodically or whenever the parking
brake shoes and/or drum are replaced. Have your Lexus dealer perform the bed-
ding down.
■Operating your vehicle in a foreign country
Comply with the relevant vehicle registration laws and confirm the availability of the
correct fuel. ( →P. 5 2 1 )

128
2-1. Driving procedures
IS350/250_U
CAUTION
●Do not turn the engine off while driving.
The power steering and brake booster system will not operate properly if the
engine is not running.
●Use engine braking (downshift) 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 4 0 )
●When stopped on an inclined surface, use the brake pedal and parking brake to
prevent the vehicle from rolling backward or forward and causing an accident.
●Do not adjust the position 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 that may
result in death or serious injury.
●Always check that all passengers' arms, heads or other parts of their bodies are
not outside the vehicle, as this may result in death or serious injury.
●Do not drive the vehicle off-road.
This is not a AWD vehicle designed for real off-road driving. Proceed with all due
caution if it becomes unavoidable to drive off-road.
●Do not drive across river crossings or through other bodies of water.
This may cause electric/electronic components to short circuit, damage the
engine or cause other serious damage to the vehicle.
●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.

129
2-1. Driving procedures
2
When driving
IS350/250_U
CAUTION
■When driving on slippery road surfaces
●Sudden braking, acceleration and steering may cause tire slippage and reduce
your ability to control the vehicle, resulting in an accident.
●Sudden changes in engine speed, such as engine braking caused by up-shifting
or down-shifting, may 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 only one side are wet and not functioning
properly, steering control may be affected, resulting in an accident.
■When shifting the shift lever
With automatic transmission vehicles, be careful not to shift the shift lever with the
accelerator pedal depressed.
This may lead to unexpected rapid acceleration of the vehicle that may cause an
accident and result in death or serious injury.
■When the vehicle is stopped
●Do not race the engine.
If the vehicle is in any gear other than P (vehicles with an automatic transmission
only) or N the vehicle may accelerate suddenly and unexpectedly, and may cause
an accident.
●Do not leave the vehicle with the engine running for a long time.
If such a situation cannot be avoided, park the vehicle in an open space and
check that exhaust fumes do not enter the vehicle interior.
●With automatic transmission vehicles, always keep a foot on the brake pedal
while the engine is running to prevent an accident caused by the vehicle moving.

131
2-1. Driving procedures
2
When driving
IS350/250_U
CAUTION
■When taking a nap in the vehicle
Always turn the engine off. Otherwise, you may accidentally move the shift lever or
depress the accelerator pedal, which could cause an accident or fire due to engine
overheating. Additionally, if the vehicle is parked in a poorly ventilated area, exhaust
gases may collect and enter the vehicle, leading to death or a serious health hazard.
■When braking the vehicle
●When the brakes are wet, drive more cautiously.
Braking distance increases when the brakes are wet, and 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 downhills 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.
●Do not pump the brake pedal if the engine stalls.
Each push on the brake pedal uses up the reserve for the power-assisted brakes.
●The brake system consists of 2 individual hydraulic systems: if one of the systems
fails, the other will still operate. In this case, the brake pedal should be depressed
more firmly than usual and braking distance becomes longer.
Do not drive your vehicle with only a single brake system. Have your brakes fixed
immediately.
■If the vehicle becomes stuck or bogged (AWD models)
Do not spin the wheels recklessly when any of the tires is up in the air, or stuck in
sand or mud, etc. This may damage the drive system components or propel the
vehicle forward (or in another direction) and cause an accident.

176
2-4. Using other driving systems
IS350/250_U
■Adjusting the speed setting
Increase speed
Decrease speed
Hold the lever until the desired
speed setting is obtained.
Fine adjustment of the set
speed (approximately 1.0 mph
[1.6 km/h]) can be made by
lightly pressing the lever up or
down and releasing it.
■Canceling and resuming regular acceleration
Cancel
Push the lever towards you to
cancel cruise control.
The speed setting is also can-
celed when the brakes are
applied or the clutch (manual
transmission) is depressed.
Resume
To resume cruise control and
return to the set speed, push the
lever up.

182
2-4. Using other driving systems
IS350/250_U
■Canceling and resuming the speed setting
Cancel
Push the lever towards you to
cancel cruise control.
The setting is also canceled
when the brakes are applied.
Resume
To resume cruise control and
return to the set speed, push the
lever up.
■Changing the vehicle- to-vehicle distance
Each push of the switch changes
the vehicle-to-vehicle distance
Long
Medium
Short
The vehicle-to-vehicle distance
is automatically set to the long
mode when the “ENGINE
START STOP” switch is
switched to IGNITION ON
mode.
A mark will be displayed to indi-
cate the presence of the vehicle
if a vehicle is running ahead of
you.
Preceding
vehicle mark

183
2-4. Using other driving systems
2
When driving
IS350/250_U
Driving in vehicle-to-vehicle distance control mode
This mode employs a radar sensor to detect the presence of vehicles up
to 400 ft. (120 m) ahead of you and to judge the distance between your
vehicle and those vehicles.
Note that vehicle-to-vehicle distance will close when traveling on long
downhill slopes.
Example of constant speed cruising (when there are no vehicles
ahead): When set to 62 mph (100 km/h)
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
switch.
Example of deceleration cruising (when the vehicle ahead is driving
slower than the set speed): When fixed speed cruising is set at 62 mph
(100 km/h) and the vehicle ahead is driving at 50 mph (80 km/h)
When a vehicle is detected running ahead of you, in the same lane, the sys-
tem automatically decelerates your vehicle. When a greater reduction in
vehicle speed is necessary, the system applies the brakes. A warning tone
warns you when the system cannot decelerate sufficiently to prevent your
vehicle from closing on the vehicle ahead.
Example of follow-up cruising (when following a vehicle driving slower
than the set speed): When the speed is set to 62 mph (100 km/h) and
the vehicle ahead is driving at 50 mph (80 km/h)

187
2-4. Using other driving systems
2
When driving
IS350/250_U
CAUTION
■Before using dynamic radar cruise control
Do not overly rely on vehicle-to-vehicle distance control.
Be aware of the set vehicle speed. If automatic deceleration/acceleration is not
appropriate, adjust the vehicle speed, as well as the distance between your vehicle
and vehicles 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 intended 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 close attention to the vehicle's surroundings.
●Assisting the driver to judge proper following distance.
The dynamic radar cruise control determines whether the following distance
between the driver's own vehicle and a designated vehicle traveling 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 possibility 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 traveling 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
Keep the “ON-OFF” button off when not in use.

188
2-4. Using other driving systems
IS350/250_U
CAUTION
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate control of speed 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 those covered with rain, ice or snow
●On steep downhills, or where there are sudden changes between sharp up and
down gradients
●At entrances to expressways
●When weather conditions are bad enough that they may prevent the sensors
from functioning correctly (fog, snow, sandstorm, etc.)
●When a buzzer can be heard often
●When your vehicle is towing a trailer
■When the radar 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 vehicles, the prox-
imity alarm (→P. 480) will not be activated, and an accident may result.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving
●Vehicles with small rear ends (trailers with no load on board etc.)
●Motorcycles traveling in the same lane

189
2-4. Using other driving systems
2
When driving
IS350/250_U
CAUTION
■Conditions under which the vehicle-to-vehicle distance control may not function
correctly
Apply the brakes as necessary in the following conditions as the radar sensor may
not be able to correctly detect vehicles ahead, and an accident may result.
●When water or snow thrown up by the surrounding vehicles hinders the function-
ing of the sensor
●When your vehicle is pointing upwards (caused by a heavy load in the trunk, etc.)
●When the road curves or when the lanes are narrow
●When steering wheel operation or your position in the lane is unstable
●When the vehicle ahead of you decelerates suddenly
■Handling the radar sensor
Observe the following to ensure the cruise control system can function effectively:
●Keep the sensor and front grille clean at all times.
Clean the sensor and front grille with a soft cloth so you do not mark or damage
them.
●Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off position, the system may malfunction. If the
sensor or surrounding area is subject to a strong impact, always have the area
inspected and adjusted by a Lexus dealer.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to the sensor, grille or surrounding area.
●Do not modify or paint the sensor and grille.
■To ensure the radar sensor functions correctly
Do not do the following to the sensor or grille cover as doing so may cause the sen-
sor not to function correctly and could result in an accident.
●Stick or attach anything to them
●Leave them dirty
●Disassemble, or subject them to strong shocks
●Modify or paint them
●Replace them with non-genuine parts