2007 Lexus IS250 sensor

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)

156
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.

164
2-5. Driving information
NOTICE
■Repairing or replacing snow tires
Request repairs of and obtain replacement snow tires from Lexus dealers or legiti-
mate tire retailers.
This is because the removal and attachment of snow tires affects the operation of
the tire air pressure sensor.
■Fitting tire chains
The tire air pressure sensor may not function correctly when tire chains are fitted.

223
3-5. Other interior features
3
Interior features
■Items that can be set using the satellite switches
Lexus parking assist-sensor (P. 142) ON/OFF
(if equipped)
Tire pressure warning system initialization
(P. 285)
ID code selection for tire air pressure system
(P. 2 8 6 )
AFS (Adaptive Front-lighting System) (P. 1 2 3 )
ON/OFF (if equipped)
Vehicle speed indicator ON/OFF and speed set-
ting (P. 111)
Tacho indicator ON/OFF and engine speed (rpm)
setting (P. 111)

224
3-5. Other interior features
■Changing the settings
Each item is displayed and its setting can be changed only in the following condi-
tions:
●Lexus parking assist-sensor: When the engine switch is in IG-ON mode.
●Items other than the above: When the engine switch is in IG-ON mode and the
vehicle is stopped.
■Display
The display will return to the original display if the satellite switches are not oper-
ated for an extended period.
Even if the display is in satellite switch mode, it will switch in the event of a warning
or when the radar cruise control is used. If this occurs, press any of the satellite
switches or DISP switch on the steering wheel to return the display to satellite
switch mode.

249
3-5. Other interior features
3
Interior features
CAUTION
■While driving the vehicle
Do not adjust the display. Be sure to adjust the display only when the vehicle is
stopped.
■When doing the circling calibration
Be sure to secure a wide space, and watch out for people and vehicles in the neigh-
borhood. Do not violate any local traffic rules while performing circling calibration.
NOTICE
■To avoid the compass malfunctions
Do not place magnets or any metal objects near the inside rear view mirror.
Doing this may cause a malfunction of the compass sensor.
■To ensure normal operation of the compass
●Do not perform circling calibration of the compass in a place where the earth's
magnetic field is subject to interference by artificial magnetic fields.
●During calibration, do not operate electric systems (moon roof, power windows,
etc.) as they may interfere with the calibration.

284
4-3. Do-it-yourself maintenance
Directional tires
Tire direction marks
The tires listed below are direc-
tional. The tire sidewalls are
marked with arrows indicating the
rolling direction of the tire. If
mounted on the wrong side of the
vehicle, directional tires will per-
form poorly.
Installing tire inflation pressure sensors
When replacing tires or wheels, tire pressure sensors must also be
installed. Tire pressure sensors can be installed in any of the following
three ways:
■The tire pressure warning system
Your Lexus is equipped with a tire pressure warning system that uses
tire pressure sensors to detect low tire pressure before serious
problems arise. (P. 341, 345)
Before removing the tire from the wheel, remove the system’s tire
inflation pressure sensor. Be careful not to damage the sensor when
removing and installing the tires.
Tire size of turning directional tires
Front225/45R17 90W
225/40R18 88Y
Rear245/45R17 95W
255/40R18 95Y

285
4-3. Do-it-yourself maintenance
4
Maintenance and care
●Sensors can be removed from the old wheels and installed on the new
wheels.
●When replacing only the tire, the sensor already installed on the wheel
does not need to be replaced.
●Replacing both a wheel and its sensor.
When new tire pressure sensors are installed, new sensor ID codes must be
registered in the ECU and tire inflation pressure sensor must be initialized.
(P. 285, 286)
Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following
circumstances:
●When the standard tire pressure changes by replacing tires or
wheels
●When tires are rotated.
●When tire pressure sensors are replaced.
●When driving with the tires inflated to a higher than standard tire
pressure.
When the tire pressure warning system is initialized, the current tire
pressure is set as the pressure benchmark.
■How to initialize the tire pressure warning system
To initialize the system, use the satellite switch. (P. 222)
Park the vehicle in safe place and turn off the engine.
Adjust the tire pressure to the specified pressure (P. 389)
Start the engine.
Make sure to adjust the tire pressure to the specified level. The tire infla-
tion pressure warning system will operate based on this pressure level.
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STEP3