2007 Lexus IS250 brake

154
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.

155
2-4. Using other driving systems
2
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)

161
2-5. Driving information
2
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.

162
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.

167
2-5. Driving information
2
When driving
Dinghy towing (vehicles with a manual transmission)
Towing your vehicle with 4 wheels on the ground
To prevent damage to your vehicle, perform the following procedures
before towing.
Shift the shift lever to neutral.
Switch to ACC mode. (P. 9 8 )
Ensure that the audio system and other powered devices have been
turned OFF.
Release the parking brake.
After towing, leave the engine in idle for at least 3 minutes before driv-
ing the vehicle.
■Necessary equipment and accessories
Specialized equipment and accessories are required for dinghy towing. Contact
the service branch of the motor home manufacturer regarding recommended
equipment.
Your vehicle can be dinghy towed in a forward direction (with 4 wheels on
the ground) behind a motor home.
STEP1
STEP2
STEP3

259
4-2. Maintenance
4
Maintenance and care
General maintenance
Engine compartment
ItemsCheck points
BatteryMaintenance-free. (P. 2 7 9 )
Brake fluidAt the correct level? (P. 2 7 8 )
Engine coolantAt the correct level? (P. 2 76 )
Engine oilAt the correct level? (P. 2 7 2 )
Exhaust systemNo fumes or strange sounds?
Radiator/condenser/hosesNot blocked with foreign matter?
(P. 2 7 8 )
Wa s h e r f l u i dAt the correct level? (P. 2 8 2 )
Listed below are the general maintenance items that should be performed
at the intervals specified in the “Warranty and Services Guide” or “Owners
Manual Supplement”. It is recommended that any problem you notice
should be brought to the attention of your Lexus dealer or qualified service
shop for advice.

260
4-2. Maintenance
Vehicle interior
ItemsCheck points
Accelerator pedal• Moves smoothly (without uneven
pedal effort or catching)?
Automatic transmission “Park”
mechanism• Can the vehicle be hold securely
on an incline with the shift lever in
P?
Brake pedal
• Moves smoothly?
• Does it have appropriate clearance
and correct amount of free play?
Brakes
• Not pull to one side when applied?
• Loss of brake effectiveness?
• Spongy feeling brake pedal?
• Pedal almost touches floor?
Head restraints• Move smoothly and lock securely?
Indicators/buzzers•Function properly?
Lights
• Do all the lights come on?
• Headlights aimed correctly?
(P. 3 1 8 )
Parking brake
• Moves smoothly?
• Can hold the vehicle securely on
an incline?
Seat belts
• Does the seat belt system operate
smoothly?
• Are the belts undamaged?
Seats• Do the seat controls operate prop-
erly?

263
4
Maintenance and care
4-3. Do-it-yourself maintenance
Do-it-yourself service precautions
If you perform maintenance yourself, be sure to follow the correct proce-
dure given in these sections.
ItemsParts and tools
Battery condition (P. 2 7 9)
•Warm water
• Baking soda
•Grease
•Conventional wrench
(for terminal clamp bolts)
Brake fluid level (P. 2 7 8 )
• FMVSS No.116 DOT 3 or SAE
J1703 brake fluid
•Rag or paper towel
• Funnel (used only for adding brake
fluid)
Engine coolant level (P. 2 76 )
• “Toyota Super Long Life Coolant”
or similar high-quality ethylene gly-
col-based non-silicate, non-amine,
non-nitrate and non-borate coolant
with long-life hybrid organic acid
technology.
For the U.S.A.:
“Toyota Super Long Life Coolant”
is pre-mixed with 50% coolant and
50% deionized water.
For Canada:
“Toyota Super Long Life Coolant”
is pre-mixed with 55% coolant and
45% deionized water.
• Funnel (used only for adding
engine coolant)