2007 Lexus IS250 brake sensor

When driving2
89
2-1. Driving procedures ................. 90
Driving the vehicle ....................... 90
Starting the engine ...................... 98
Automatic Transmission ........... 101
Manual Transmission ................ 105
Turn signal lever .......................... 107
Parking brake ............................... 108
2-2. Instrument cluster................... 109
Gauges and meters .................. 109
Indicators and warning
lights................................................ 115
Multi-information display ......... 118
2-3. Operating the lights and
windshield wipers ................. 122
Headlight switch ......................... 122
Fog light switch............................ 125
Windshield wipers and
washer.......................................... 126
Headlight cleaner switch ........ 1292-4. Using other driving
systems .................................... 130
Cruise control ............................. 130
Dynamic radar cruise
control ......................................... 133
Lexus parking
assist-sensor............................... 142
Driving assist systems............... 148
PCS (Pre-Collision
System)........................................ 154
2-5. Driving information................ 157
Cargo and luggage.................... 157
Vehicle load limits ...................... 160
Winter driving tips ....................... 161
Trailer towing................................ 165
Dinghy towing
(vehicles with an
automatic transmission) ....... 166
Dinghy towing
(vehicles with a manual
transmission) .............................. 167

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2-3. Operating the lights and windshield wipers
2
When driving
AFS (vehicles with discharge headlights)
AFS (Adaptive Front Lighting System) improves visibility at intersections
and on curves by automatically adjusting the level of the headlights
according to vehicle speed and the degree of the tire angle that are con-
trolled by steering input.
Operates at speeds of 6 mph (10 km/h) or higher.
■Deactivating AFS
How to switch: P. 2 2 2
The indicator turns on when the AFS is deactivated.
■Daytime running light system
To make your vehicle more visible to other drivers, the headlights turn on automati-
cally (at a reduced intensity) whenever the engine is started and the parking brake
is released. Daytime running lights are not designed for use at night.
■Headlight control sensor
The sensor may not function properly if an
object is placed on the sensor, or anything
that blocks the sensor is affixed to the wind-
shield.
Doing so interferes with the sensor detecting
the level of ambient light and may cause the
automatic headlight system to malfunction.

136
2-4. Using other driving systems
Driving in vehicle-to-vehicle distance control mode
This mode employs a radar sensor to detect the presence of vehicles
within 328 ft. (100 m) ahead and to judge the distance between your
vehicle and those vehicles.
Note that vehicle-to-vehicle distance will close when traveling on long down-
hill 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 on the system cannot decelerate sufficiently to prevent your vehi-
cle 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)

140
2-4. Using other driving systems
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 serious or
fatal accident.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as those covered with rain, ice or snow.
●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.)
●Where buzzer can be heard often
■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. 344) 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

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2-4. Using other driving systems
2
When driving
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
■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, subject them to strong shocks
●Modify or paint them
●Replace them with non-genuine parts

146
2-4. Using other driving systems
■Sensor detection information
●Certain vehicle conditions and the surrounding environment may affect the
ability of the sensor to correctly detect obstacles. Particular instances where this
may occur are listed below.
• There is dirt, snow or ice on the sensor.
• The sensor is frozen.
•The sensor is covered in any way.
• The vehicle is leaning considerably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on grass.
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle engines,
air brakes of large vehicles, or other loud noises producing ultrasonic waves.
• There is another vehicle equipped with parking assist sensors in the vicinity.
• The sensor is coated with a sheet of spray or heavy rain
• The vehicle is equipped with a fender pole or wireless antenna.
• Towing eyelets are installed.
• The bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or curved curb.
• In harsh sunlight or intense cold weather
In addition to the examples above, there are instances in which, because of their
shapes, signs and other objects may be judged by the sensor to be closer than they
are.
●The shape of the obstacle may prevent the sensor from detecting it. Pay particu-
lar attention to the following obstacles.
• Wires, fences, ropes etc.
• Cotton, snow and other materials that absorb radio waves
• Sharply-angled objects
• Low obstacles
• Tall obstacles with upper sections projecting outwards in the direction of your
vehicle
■When the display flashes and a message is displayed
P. 3 4 4
■Certification (Canada only)
This ISM device compiles with Canadian ICES-001.
■Customization
Settings (e.g. buzzer volume) can be changed. (P. 406)

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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
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)