2012 Lexus IS F brake light

195
2-4. Using other driving systems
2
When driving
■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.
• A towing eyelet is 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 object s may be judged by the sensor to be closer than they
are.
●The shape of the obstacle may prevent th e 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 projec ting outwards in the direction of your
vehicle
■If the display flashes and a message is displayed
 P. 4 7 3

200
2-4. Using other driving systems
■When the “TRAC OFF” indicator light comes on even if the VSC off switch has
not been pressed
TRAC and hill-start assist control cannot be operated. Contact your Lexus dealer.
■Automatic reactivation of the TRAC/VSC systems
If the TRAC/VSC systems are turned off, re-starting the engine will automatically
reactivate them.
■Automatic TRAC reactivation
If only the TRAC system is turned off, the TRAC system will turn on when vehicle
speed increases.
■Automatic TRAC and VSC reactivation
If the TRAC and VSC systems are turned off, the systems will not turn on even when
vehicle speed increases.
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC and hill-start
assist control systems
●A sound may be heard from the engine compartment if the brake pedal is
depressed repeatedly when the engine is started or just after the vehicle begins
to move. This sound does not indicate th at a malfunction has occurred in any of
these systems.
●Any of the following conditions may occur when the above systems are operat-
ing. None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly when the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.
■Hill-start assist control is operational when
●The shift lever is in the D or M position.
●The brake pedal is not depressed.
●The vehicle rolls backward.
■EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be
heard. This does not indicate a malfunction.

203
2-4. Using other driving systems
2
When driving
PCS (Pre-Collision System)
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
: If equipped
When the radar sensor detects possibil ity of a frontal collision, the pre-
collision system such as the brakes and seat belts are automatically
engaged to lessen impact and injuries to occupants as well as vehicle dam-
age.
■ Pre-collision seat belts
If the pre-collision sensor detects that a collision is unavoidable, the pre-
collision system will retract the seat belt before the collision occurs.
The same will happen if the driver makes an emergency braking or loses
control of the vehicle. ( P. 6 6 )
However, the system will not operate in the event of skidding when the
VSC system are disabled.
■ Pre-collision brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how strongly the brake pedal is
depressed.
■Pre-collision braking
When there is a high possibility of a frontal collision, the system warns the
driver using a warning light, warnin g display and buzzer. If the system
determines that a collision is unavoidable, the brakes are automatically
applied to reduce the collision speed. The pre-collision braking function
can be turned on and off using the satellite switch.

204
2-4. Using other driving systems
Disabling the pre-collision brakingThe pre-collision braking function
can be turned on and off using the
satellite switch. (P. 343)
Press “ ” or “ ” to display the
“PCS BRAKE” setting ( ). Then,
press the “ON/OFF” button in the
middle of the switch to select either
“ON” or “OFF” ( ).
It may take approximately 3 sec-
onds for the display to change after
the satellite switch is operated.
The “PCS” warning light flashes
when “OFF” is selected.
■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.

206
2-4. Using other driving systems
●When an extreme change in vehicle height occurs
●When the axis of the radar is out of adjustment
●When passing through certain toll gates
●When driving on a bridge.
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. 463, 473)
■Situations in which the pre-collision system does not function properly
The system may not function effectively in situations such as the following:
●On roads with sharp be nds or uneven surfaces
●If a vehicle suddenly moves in front of your vehicle, such as at an intersection
●If a vehicle suddenly cuts in front of your vehicle, such as when overtaking
●In inclement weather such as heav y rain, fog, snow or sand storms
●When your vehicle is skidding with the VSC system off
●When an extreme change in vehicle height occurs
●When the axis of the radar is out of adjustment
■Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor contamination, etc. that results in the
sensors being unable to detect obstacles, the pre-collision system will be automati-
cally disabled. In this case, the system will not activate even if there is a collision pos-
sibility.

387
4-2. Maintenance
4
Maintenance and care
Vehicle interior
ItemsCheck points
Accelerator pedal• Moves smoothly (without uneven pedal effort or catching)?
Automatic transmission “Park”
mechanism• Can the vehicle be held 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. 4 4 5 )
Pa r k i n g b r a ke
• 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?

405
4-3. Do-it-yourself maintenance
4
Maintenance and care
■Adding fluid
Make sure to check the fluid type and prepare the necessary items.
Fluid typeFMVSS No.116 DOT 3 or SAE J1703 brake fluid
ItemsClean funnel
■Brake fluid can absorb moisture from the air
Excess moisture in the fluid can cause a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
CAUTION
■When filling the reservoir
Take care because brake fluid can harm your hands or eyes and damage painted
surfaces.
If fluid gets on your hands or in your eyes, flush the affected area with clean water
immediately.
If you still experience discomfort, see a doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear or
when the fluid level in the accumulator is high.
If the reservoir needs frequent refilli ng, it may indicate a serious problem.

5
When trouble arises
463
5-2. Steps to take in an emergency
If a warning light turns on or a warning buzzer sounds...
Stop the vehicle immediately. Continuing to drive the vehicle may be dangerous.
The following warning indicates a possible problem in the brake system.
Immediately stop the vehi cle in a safe place and contact your Lexus
dealer.
*: Parking brake engaged warning buzzer:
 P. 4 7 7
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Brake system warning light (warning buzzer)*
•Low brake fluid
• Malfunction in the brake booster system
This light also comes on when the parking brake is not
released. If the light turns off after the parking brake is fully
released the system is operating normally.
Calmly perform the following actions if any of the warning lights turn on or
flash. If a light turns on or flashes, bu t then turns off, this does not necessar-
ily indicate a malfunction in the system.