Lexus IS F 2008 Do-It-Yourself Maintenance /

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2-4. Using other driving systems
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When driving
CAUTION
The following situations may lead to an accident resulting in serious injury or even
death.
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded.
●The vehicle hydroplanes while driving at high speed on the wet or slick road.
■Stopping distance when the ABS is operating will exceed that of normal condi-
tions
The ABS is not designed to shorten the vehicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you in the following situations.
●When driving on dirt, gravel or snow-covered roads
●When driving over bumps in the road
●When driving over roads with potholes or roads with uneven roads
■TRAC may not operate effectively when
Directional control and power may not be ac hievable 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
The hill-start assist control may not operate effectively on steep inclines and roads
covered in ice.
■When the VSC is activated
The slip indicator light flashes and a warning buzzer sounds. Always drive carefully.
Reckless driving may cause an accident. Ex ercise particular care when the indica-
tor light flashes and a buzzer sounds.
■When TRAC and VSC are off
Be especially careful and drive at a speed appropriate to the road conditions. As
there are systems to ensure vehicle stability and driving force, do not turn off TRAC
and VSC unless necessary.

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2-4. Using other driving systems
CAUTION
■Replacing tires
Make sure that all tires are of the designated size and total load capacity, and of the
same brand and tread pattern. In addition, ma ke 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 info rmation 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
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When driving
PCS (Pre-Collision System) (if equipped)
Radar sensorDetects 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 help lessen impact and inju ries to occupants as well as vehicle
damage when the radar sensor detect s an unavoidable frontal collision.
■Pre-collision seat belts
The seat belts are immediately retracted as the effect of the pretensioner is
increased ( P. 52), to provide even greate r 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 relati on 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
■The pre-collision system is operational when
●Pre-collision 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 oncomingvehicle exceeds about 18 mph (30 km/h).
• The front occupants are wearing a seat belt.
●Pre-collision seat belts (linked to brake operation)
• Vehicle speed exceeds 18 mph (30 km/h).
• The system detects sudd en braking or skidding.
• The front occupants are wearing a seat belt.
●Pre-collision 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. 350, 360)

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2-4. Using other driving systems
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When driving
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.

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2-5. Driving information
Cargo and luggage
Capacity and distributionCargo capacity depends on the to tal weight of the occupants.
(Cargo capacity) = (Total load capa city) — (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 th e 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 av ailable 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 no t 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 tru nk 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
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When driving
(6)If your vehicle will be towing a trailer, load from your trailer will betransferred to your vehicle. Consul t 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 lo ad capacity of 660 lb. (300 kg), the
available amount of cargo and luggage load capacity will be as follows:
660 lb. — 366 lb. = 294 lb. (300 kg —166 kg = 134 kg)
In this condition, if 2 more passengers with the combined weight of 258 lb.
(176 kg) get on, the available cargo and luggage load will be reduced as fol-
lows:
294 lb. — 258 lb. = 36 lb. (134 kg — 117 kg = 17 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
CAUTION
■Things that must not be carried in the trunk
The following things may cause a fire if loaded in the trunk.
●Receptacles containing gasoline
●Aerosol cans
■Storage precautions
●Do not place items in or on the following locations:
• At the feet of the driver
• On the front passenger or rear seats (when stacking items)
• Package tray (behind the rear seatback)
•Instrument panel
•Dashboard
Items placed in the above locations could get thrown around in the event of sud-
den braking or an accident and injure the vehicle occupants.
In addition, items could block the driver’s field of vision or move during sharp
acceleration or turning. If items move about they may get under the brake or
accelerator pedals, preventing them from being depressed properly, or hit the
driver or passengers. In these situations, the driver’s control of the vehicle could
be impaired, causing an accident.
●Secure all items in the occupant compartment, as they may shift and injure some-
one during an accident or sudden braking.
■Luggage capacity and distribution
Observe the following precautions. Failure to do so will not only put load on the
tires, but also reduce steering and braking performance. This could lead to an acci-
dent resulting in serious injury or even death.
●Do not overload the vehicle.
●Do not apply load to the vehicle unevenly.

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2-5. Driving information
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When driving
Vehicle load limits
■Total load capacity and seating capacity
These details are also described on the tire and loading information label.
(  P. 3 0 7 )
CAUTION
■Overloading the vehicle
Do not overload the vehicle.
It may not only cause damage to the tire s, but also degrade steering and braking
ability, resulting in an accident.
Vehicle load limits include total lo ad capacity, seating capacity, towing
capacity and cargo capacity.
■ Total load capacity: 660 lb. (300 kg)
Total load capacity means the combined weight of occupants, cargo and
luggage.
■ Seating capacity: 4 occupants (Front 2, Rear 2)
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
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 appropria te 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.
Ensure that all tires are the specified size and the same brand.
■Before driving the vehicle
Perform the following according to the driving conditions.
● Do not try to forcibly open a w indow 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 accumu lated on the air inlet vents in
front of the windshield.
● Remove any ice that has accumul ated 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.