2008 Lexus GS350 Brake

175
2-4. Using other driving systems
2
When driving
GS_G_U
June 19, 2008 12:54 pm
■When using the intuitive parking assist
●The sensors’ detection areas and reaction times are limited. When moving for-
ward or reversing, check the areas surrounding the vehicle (especially the sides
of the vehicle) for safety, and drive slowly, using the brake to control the vehicle’s
speed.
• The sensors’ detection areas are limited to the areas around the vehicle’s frontand rear bumpers.
• Depending on the shape of the obstacle and other factors, the detection dis- tance may shorten, or detection may be impossible.
• There will be a short delay between obstacle detection and display. Even at
slow speeds, there is a possibility that the obstacle will come within 0.8 ft. (25
cm) of the vehicle before the display is shown and the warning beep sounds.
• Braking distance may differ according to the road conditions (rain, gravel etc.).
• It might be difficult to hear beeps due to the volume of audio system or air flow noise of air conditioning system.
• For long obstacles such as walls, the obstacle warning may change as the obstacle gets closer.
GS_U_G.book Page 175 Thursday, June 19, 2008 12:54 PM

184
2-4. Using other driving systems
GS_G_U
June 19, 2008 12:54 pm
Driving assist systems
To help enhance driving safety and performance, the following systems
operate automatically in response to various driving situations. Be aware,
however, that these systems are supplementary and should not be relied
upon too heavily when operating the vehicle.
■ ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if
the brakes are applied while driving on a slippery road surface.
■Brake assist
Generates an increased level of braking force after the brake pedal is
depressed, when the system detects a panic stop situation.
■VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or turning on
slippery road surfaces.
■TRAC (Traction Control)
Maintains drive power and prevents the rear wheels from spinning when
starting the vehicle or accelerating on slippery roads.
■Hill-start assist control
Helps prevent the vehicle from rolling backwards when starting on an
incline or slippery slope. It operates for approximately 5 seconds at maxi-
mum.
■EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel.
■Active stabilizer suspensi on system (if equipped)
Turns at smaller angles to maintain the stable vehicle posture.
GS_U_G.book Page 184 Thursday, June 19, 2008 12:54 PM

185
2-4. Using other driving systems
2
When driving
GS_G_U
June 19, 2008 12:54 pm
When the VSC/TRAC/hill-start assist control systems are operatingIf the vehicle is in danger of slip-
ping, rolling backwards when
starting on an incline, or if the rear
wheels (2WD models) or all
wheels (4WD models) spin, the
slip indicator light flashes to indi-
cate that the VSC/TRAC/hill-start
assist control systems have been
engaged.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
The stop lights and high mounted
stoplight turn on when the hill-start
assist control system is operating.
The slip indicator light flashes as
well when ABS is operating.
■PCS (Pre-Collision System) (if equipped)
→ P. 1 9 0
■VGRS (Variable Gear Ratio Steering) (GS460)
Adjusts the wheel turning angle in accordance with the vehicle speed and
steering wheel movement.
■VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, VSC, TRAC, hill-start assist con-
trol, VGRS (GS460) and EPS systems.
Maintains vehicle stability when swerving on slippery road surfaces by
controlling the brakes, engine output, and the movement of the front
wheels.
GS_U_G.book Page 185 Thursday, June 19, 2008 12:54 PM

187
2-4. Using other driving systems
2
When driving
GS_G_U
June 19, 2008 12:54 pm
■Automatic reactivation of TRAC and VSC
Turning the “ENGINE START STOP” switch OFF after turning off the TRAC and
VSC systems will automatically re-enable them.
■Automatic TRAC reactivation
If only the TRAC system is turned off, the TRAC system will turn on when the vehi-
cle speed increases.
■Automatic TRAC and VSC reactivation
If the TRAC and VSC systems are turned off, the systems will not turn on even when
the vehicle speed increases.
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC, hill-start
assist control and VGRS (GS460) systems
●A sound may be heard from the engine compartment when the engine is
started or just after the vehicle begins to move. This sound does not indicate that
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 after the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.
■Hill-start assist control operating conditions
This system comes into operation under the following conditions after the brake
pedal has been depressed and the vehicle has come to a stop:
●The shift lever is in the “D” or “S”.
●The system has detected that the vehicle is moving backwards.
●GS350: The brake pedal is not depressed.
GS_U_G.book Page 187 Thursday, June 19, 2008 12:54 PM

190
2-4. Using other driving systems
GS_G_U
June 19, 2008 12:54 pm
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 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 (front seats only)
The seat belts are immediately retracted as the effect of the pretensioner is
increased ( →P. 54), to help prepare 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.
■Pre-collision AVS
If the system determines that the collision is unavoidable, the operation of
AV S ( →P. 183) helps prevent the vehicle front from going down when
hard brakes are applied.
GS_U_G.book Page 190 Thursday, June 19, 2008 12:54 PM

191
2-4. Using other driving systems
2
When driving
GS_G_U
June 19, 2008 12:54 pm
■Obstacles not detected
The sensor cannot detect plastic obstacles such as pylons. There may also be occa-
sions when the radar sensor cannot detect pedestrians, animals, bicycles, motorcy-
cles, trees, or snowdrifts.
■The pre-collision system is operational when
●Seat belts (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 18 mph (30 km/h).
• The front occupants are wearing a seat belt.
●Seat belts (linked to brake operation)
• Vehicle speed exceeds 18 mph (30 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 oncoming vehicle exceeds 18 mph (30 km/h).
• The brake pedal is depressed.
●AV S
• Vehicle speed is above 3 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or oncoming
vehicle exceeds 18 mph (30 km/h).
GS_U_G.book Page 191 Thursday, June 19, 2008 12:54 PM

192
2-4. Using other driving systems
GS_G_U
June 19, 2008 12:54 pm
■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. 489, 499)
GS_U_G.book Page 192 Thursday, June 19, 2008 12:54 PM

199
2-5. Driving information
2
When driving
GS_G_U
June 19, 2008 12:54 pm
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 same size and 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.
GS_U_G.book Page 199 Thursday, June 19, 2008 12:54 PM