Lexus IS250 2007 Basic Functions / LEXUS 2007 IS350/250 OWNER'S MANUAL (OM53578U)

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2-4. Using other driving systems
2
When driving
CAUTION
■TRAC may not operate effectively when
Directional control and power may not be achievable while driving on slippery road
surfaces, even if the TRAC system is operating.
Do not drive the vehicle in conditions where stability and power may be lost.
■If hill-start assist control does not operate effectively
(vehicles with an automatic transmission)
The hill-start assist control may not operate effectively on steep inclines and roads
covered in ice.
■Replacing tires
Make sure that all tires are of the same size, brand, tread pattern and total load
capacity. In addition, make sure that the tires are inflated to the recommended tire
pressure level.
The ABS and VSC systems will not function correctly if different tires are fitted on
the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels.
■Handling of tires and suspension
Using tires with any kind of problem or modifying the suspension will affect the driv-
ing assist systems, and may cause the system to malfunction.

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2-4. Using other driving systems
PCS (Pre-Collision System) (if equipped)
Radar sensor
Detects vehicles or other obsta-
cles on or near the road ahead and
determines whether a collision is
imminent based on the position,
speed, and heading of the obsta-
cles.
Grille cover
Radar sensor
Safety systems such as the brakes and seat belts are automatically
engaged to lessen impact and injuries to occupants as well as vehicle dam-
age when the radar sensor detects an unavoidable frontal collision.
■Pre-collision seat belts
The seat belts are immediately retracted as the effect of the pretensioner is
increased (P. 35), to provide even greater constraining force to protect
the driver and passengers. In the event of sudden braking or skidding, the
system will operate even if no obstacle has been detected.
■Pre-collision brake assist
Applies greater braking force in relation to how strongly the brake pedal is
depressed.
■Obstacles not detected
The sensor cannot detect plastic obstacles such as pylons. There may also be occa-
sions when the sensor cannot detect pedestrians, animals, bicycles, motorcycles,
trees, or snowdrifts.

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2-4. Using other driving systems
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When driving
■The pre-collision system is operational when
●Seat belt (linked to the radar sensor)
• Vehicle speed is above 3 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or oncoming
vehicle exceeds 18 to 24 mph (30 to 40 km/h).
• The front occupants are wearing a seat belt.
●Seat belts (linked to brake operation)
• Vehicle speed exceeds 9 mph (15 km/h).
• The system detects sudden braking or skidding.
• The front occupants are wearing a seat belt.
●Brake Assist
• Vehicle speed is above 18 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle is
greater than 18 to 24 mph (30 to 40 km/h).
• The brake pedal is depressed.
■Conditions that may trigger the system even if there is no danger of collision
●When there is an object by the roadside at the entrance to a curve
●When passing an oncoming vehicle on a curve
●When driving over a narrow iron bridge
●When there is a metal object on the road surface
●When driving on an uneven road surface
●When passing an oncoming vehicle on a left-turn
●When your vehicle rapidly closes on the vehicle in front
When the system is activated in the situations described above there is also a possi-
bility that the seat belts will retract quickly and the brakes will be applied with a force
greater than normal. When the seat belt is locked in the retracted position, stop the
vehicle in a safe place, release the seat belt and refasten.
■When there is a malfunction in the system
Warning lights and/or warning messages will turn on or flash. (P. 339, P. 344)

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2-4. Using other driving systems
CAUTION
■Handling the radar sensor
Observe the following to ensure the pre-collision 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 are 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 guard or surrounding
area.
■Limitations of the pre-collision system
Do not rely on the pre-collision system. Always drive safely, taking care to observe
your surroundings and checking for any obstacles or other road hazards.

157
2
When driving
2-5. Driving information
Cargo and luggage
Capacity and distribution
Cargo capacity depends on the total weight of the occupants.
(Cargo capacity) = (Total load capacity) — (Total weight of occupants)
Steps for Determining Correct Load Limit 
(1) Locate the statement “The combined weight of occupants and cargo
should never exceed XXX kg or XXX lbs.” on your vehicle’s placard.
(2)Determine the combined weight of the driver and passengers that will
be riding in your vehicle.
(3)Subtract the combined weight of the driver and passengers from
XXX kg or XXX lbs.
(4)The resulting figure equals the available amount of cargo and luggage
load capacity.
For example, if the “XXX” amount equals 1400 lbs. and there will be
five 150 lb passengers in your vehicle, the amount of available cargo
and luggage load capacity is 650 lbs. (1400  750 (5150) = 650
lbs.)
(5)Determine the combined weight of luggage and cargo being loaded
on the vehicle. That weight may not safely exceed the available cargo
and luggage load capacity calculated in Step 4.
Take notice of the following information about storage precautions, cargo
capacity and load.
●Stow cargo and luggage in the trunk whenever possible. Be sure
all items are secured in place.
●Be careful to keep the vehicle level. Placing the weight as far for-
ward as possible helps maintain vehicle balance.
●For better fuel economy, do not carry unnecessary weight.

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2-5. Driving information
(6) If your vehicle will be towing a trailer, load from your trailer will be
transferred to your vehicle. Consult this manual to determine how this
reduces the available cargo and luggage load capacity of your vehi-
cle.
Lexus does not recommend towing a trailer with your vehicle. Your vehicle is
not designed for trailer towing.
Example on your vehicle
Cargo capacity
Total load capacity
When 2 people with the combined weight of 366 lb. (166 kg) are riding
in your vehicle, which has a total load capacity of 825 lb. (375 kg), the
available amount of cargo and luggage load capacity will be as follows:
825 lb. — 366 lb. = 459 lb. (375 kg —166 kg = 209 kg)
In this condition, if 3 more passengers with the combined weight of 388 lb.
(176 kg) get on, the available cargo and luggage load will be reduced as fol-
lows:
459 lb. — 388 lb. = 71 lb. (209 kg — 176 kg = 33 kg)
As shown in the above example, if the number of occupants increases,
the cargo and luggage load equaling the combined weight of the occu-
pants who got on later, by an amount. In other words, if an increase in the
number of occupants causes an excess of the total load capacity (com-
bined weight of occupants plus cargo and luggage load), you must
reduce the cargo and luggage on your vehicle.

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2-5. Driving information
2
When driving
CAUTION
■Storage precautions
●Do not place anything on the package tray behind the rear seatback.
Such items may be thrown about and possibly injure people in the vehicle during
sudden braking or in an accident.
●Do not drive with objects on top of the instrument panel.
They may interfere with the driver’s field of view or move during sharp accelera-
tion or turning, thus impairing the driver’s control of the vehicle. In an accident
they may injure the vehicle occupants.
●Secure all items in the occupant compartment, as they may shift and injure some-
one during an accident or sudden braking.
■Capacity and distribution
●Do not exceed the maximum axle weight rating or the total vehicle weight rating.
●Even if the total load of occupant's weight and the cargo load is less than the total
load capacity, do not apply the load unevenly. Improper loading may cause dete-
rioration of steering or braking control which may cause death or serious injury.

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2-5. Driving information
Vehicle load limits
■Total load capacity and seating capacity
These details are also described on the tire and loading information label.
(P. 293)
CAUTION
■Overloading the vehicle
Do not overload the vehicle.
It may not only cause damage to the tires, but also degrade steering and braking
ability, resulting in an accident.
Vehicle load limits include total load capacity, seating capacity, towing
capacity and cargo capacity.
■Total load capacity: 825 lb. (375 kg)
Total load capacity means the combined weight of occupants, cargo and
luggage.
■Seating capacity: 5 occupants (Front 2, Rear 3)
Seating capacity means the maximum number of occupants whose esti-
mated average weight is 150 lb. (68 kg) per person.
■Towing capacity
Lexus does not recommend towing a trailer with your vehicle.
■Cargo capacity
Cargo capacity may increase or decrease depending on the weight and
the number of occupants.

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2-5. Driving information
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When driving
Winter driving tips
Carry out the necessary preparations and inspections before driving the
vehicle in winter. Always drive the vehicle in a manner appropriate to the
prevailing weather conditions.
■Pre-winter preparations
●Use fluids that are appropriate to the prevailing outside tempera-
tures.
• Engine oil
• Engine coolant
• Washer fluid
• Have a service technician inspect the level and specific gravity
of battery electrolyte.
●Have the vehicle fitted with four snow tires or purchase a set of
tire chains for the rear tires.
Ensure that all tires are the specified size and the same brand, and that
chains match the size of the tires.
■Before driving the vehicle
Perform the following according to the driving conditions.
●Do not try to forcibly open a window or move a wiper that is fro-
zen. Pour warm water over the frozen area to melt the ice. Wipe
away the water immediately to prevent it from freezing.
●To ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents in
front of the windshield.
●Remove any ice that has accumulated on the vehicle chassis.
●Periodically check for and remove any excess ice or snow that
may have accumulated in the wheel well or on the brakes.

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2-5. Driving information
Selecting snow chains
Snow chains can be mounted on 16- and 17-inch tires. They cannot be
mounted on 18-inch tires. Use the correct snow chain size when mount-
ing the snow chains. Chain size is regulated for each tire sizes.
Side chain
(0.12 in. [3 mm] in diameter)
Cross chain
(0.16 in. [4 mm] in diameter)
Regulations on the use of snow chains
●Regulations regarding the use of tire chains vary according to location
and type of road. Always check local regulations before installing
chains.
●Install the chains on the rear tires.
●Retighten the chains after driving 1 /4 - 1 /2 mile (0.5 - 1.0 km).
■When driving the vehicle
Accelerate the vehicle slowly and drive at a reduced speed suitable to
road conditions.
■When parking the vehicle
Park the vehicle and move the shift lever to P (automatic transmis-
sion) or R (manual transmission) without setting the parking brake.
The parking brake may freeze up, preventing it from being released.