2015 Lexus GS300h cruise control

2154-1. Before driving
4
Driving
GS450h_300h_OM_OM30F00E_(EE)
■Passing other vehicles
Consider the total combined length of your vehicle and trailer and ensure that
the vehicle-to-vehicle distance is sufficient before executing lane changes.
■Transmission information
To maintain engine braking efficiency, when using engine braking, when driv-
ing on a long steep downgrade, do not use the transmission in D. ( →P. 2 2 7 )
■If the engine overheats
Towing a loaded trailer up a long, steep incline in temperatures exceeding
30 °C (85 °F) may result in the engine overheating. If the engine coolant tem-
perature gauge indicates that the engine is overheating, turn the air condition-
ing off immediately, leave the road and stop the vehicle in a safe place.
( → P. 5 5 6 )
■When parking the vehicle
Always place wheel chocks under the whee ls of both the vehicle and trailer.
Firmly set the parking brake and shift the shift lever to P.
WA R N I N G
Follow all the instructions described in this section. Failure to do so could cause an acci-
dent resulting in death or serious injury.
■Trailer towing precautions
When towing, make sure that none of the weight limits are exceeded. ( →P. 211)
■To avoid accident or injury
●Do not tow a trailer when the compact spare tire is installed on your vehicle.
●Do not tow a trailer when the tire installed is repaired with the emergency tire punc-
ture repair kit.
●Do not use cruise control (if equipped), dynamic radar cruise control (if equipped) or
dynamic radar cruise control with full-speed range (if equipped) when trailer towing.
■Vehicle speed in towing
Observe the legal maximum speeds for trailer towing.
■Before descending hills or long declines
Reduce speed and downshift. However, never downshift suddenly while descending
steep or long downhill grades.
■Operation of the brake pedal
Do not hold the brake pedal depressed often or for long periods of time.
Doing so may result in the brake overheating or reduce braking effects.

2284-2. Driving procedures
GS450h_300h_OM_OM30F00E_(EE)
■Automatic deactivation of shift range selection in the D position
Shift range selection in the D position will be deactivated in the following situations:
●When the vehicle comes to a stop
●If the accelerator pedal is depressed for more than a certain period of time
●When the shift lever is shifted to other than D
■Downshifting restrictions warning buzzer
To help ensure safety and driving performance, downshifting operation may sometimes
be restricted. In some circumstances, downsh ifting may not be possible even when the
shift lever or paddle shift switch is operated. (A buzzer will sound twice.)
■Snow mode automatic deactivation
Snow mode is automatically deactivated if the power switch is turned off after driving in
snow mode.
■When driving with cruise control, dynamic radar cruise control or dynamic radar
cruise control with full-speed range activated
Even when performing the following actions with the intent of enabling engine braking,
engine braking will not activate because cruise control, dynamic radar cruise control or
dynamic radar cruise control with full-speed range will not be canceled.
●GS450h: While driving in the D position or S mode, downshifting to 7, 6, 5 or 4.
( → P. 303, 315, 327)
●GS300h: While driving in the D position, downshifting to 5 or 4. ( →P. 303, 315, 327)
●When switching the driving mode to sport mode while driving in D position. ( →P. 330)
■Restraining sudden start (Drive-Start Control)
●When the following unusual operation is performed, the engine output may be
restrained.
• When the shift lever is shifted from R to D, D to R, N to R, P to D, or P to R (D
includes S) with the accelerator pedal depressed, a warning message appears on
the multi-information display. ( →P. 4 8 2 )
• When the accelerator pedal is depressed too much while the vehicle is in reverse.
■If the shift lever cannot be shifted from P
→ P. 5 4 5
WA R N I N G
■When driving on slippery road surfaces
Be careful of downshifting and sudden acceler ation, as this could result in the vehicle
skidding to the side or spinning.

2604-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
Lexus Safety System+∗
◆PCS (Pre-Crash Safety system)
→ P. 2 6 9
◆LKA (Lane-Keeping Assist)∗
→P. 2 8 1
◆LDA (Lane Departure Alert with steering control)∗
→P. 2 9 0
◆AHS (Adaptive High-beam System)∗
→P. 2 4 0
◆Automatic High Beam∗
→P. 2 4 5
◆RSA (Road Sign Assist)
→P. 2 9 8
◆Dynamic radar cruise control with full-speed range∗
→P. 3 0 3
◆Dynamic radar cruise control∗
→P. 3 1 5
∗: If equipped
The Lexus Safety System+ consists of the following drive assist systems and
contributes to a safe and comfortable driving experience:
WA R N I N G
■Lexus Safety System+
The Lexus Safety System+ is designed to operate under the assumption that the driver
will drive safely, and is designed to help reduce the impact to the occupants and the
vehicle in the case of a collision or assist the driver in normal driving conditions.
As there is a limit to the degree of recognition accuracy and control performance that
this system can provide, do not overly rely on this system. The driver is always responsi-
ble for paying attention to the vehicle’s surroundings and driving safely.

281
4
4-5. Using the driving support systems
Driving
GS450h_300h_OM_OM30F00E_(EE)
LKA (Lane-Keeping Assist)∗
When driving on highways and freeways with white or yellow lines, this function
alerts the driver when the vehicle might depart from its lane and provides assis-
tance by operating the steering wheel to keep the vehicle in its lane. Further-
more, the system also provides steering assistance when dynamic radar cruise
control with full-speed range is operating to keep the vehicle in its lane.
The LKA system recognizes visible
white or yellow lines with the camera
sensor on the upper portion of the front
windshield.
◆Lane departure alert function
When the system determines that
the vehicle might depart from its
lane, a warning is displayed on the
multi-information display, and either
the warning buzzer sounds or the
steering wheel vibrates to alert the
driver.
When the warning buzzer sounds or
the steering wheel vibrates, check
the surrounding road situation and
carefully operate the steering wheel
to move the vehicle back to the cen-
ter within the white (yellow) lines.
∗: If equipped
Summary of functions
Functions included in LKA system

2834-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F00E_(EE)
◆Lane centering function
This function is linked with radar
cruise control and provides the
required assistance by operating the
steering wheel to keep the vehicle in
its current lane.
When radar cruise control is not
operating, the lane centering func-
tion does not operate.
If the system detects that the steering
wheel has not been operated for a
fixed amount of time or the steering
wheel is not being firmly gripped, a
warning is displayed on the multi-
information display and the function
is temporarily canceled.

2874-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F00E_(EE)
●Ve h i c l e s w a y w a r n i n g
This function operates when all of the following conditions are met.
• Setting for “Sway Warning” in of the multi-information display is set to “On”.
( → P. 111)
• Vehicle speed is approximately 50 km/h (32 mph) or more.
• Width of traffic lane is approximately 3 m (9.8 ft.) or more.
• No system malfunctions are detected. ( →P. 2 8 9 )
●Lane centering function
This function operates when all of the following conditions are met.
• LKA is turned on.
• Setting for “Steering Assist” and “Lane Center” in of the multi-information
display are set to “On”. ( →P. 111)
•System recognizes wh ite (yellow) lines.
• Dynamic radar cruise control with full-speed range is operating.
• Width of traffic lane is approximately 2.5 to 4.1 m (8.2 to 13.5 ft.).
• Turn signal lever is not operated.
• Vehicle is driven on a straight road or around a gentle curve with a radius of more
than approximately 200 m (656 ft.).
• No system malfunctions are detected. ( →P. 2 8 9 )
• Vehicle does not accelerate or decelerate by a fixed amount or more.
• Steering wheel is not operated with a steering force level suitable for changing lanes.
• ABS, VSC, TRC and PCS (Pre-Crash Safety system) are not operating.
• TRC or VSC is not turned off.
• Hands off steering wheel alert ( →P. 288) is not displayed.
• Lane departure control function is not operating.
■Temporary cancellation of functions
When operation conditions are no longer met, a function may be temporarily canceled.
However, when the operation conditions are met again, operation of the function is auto-
matically restored. ( →P. 2 8 6 )
■Lane departure control function/lane centering function
Depending on the vehicle speed, lane departure situation, road conditions, etc., the
operation of the functions may not be reco gnized or the functions may not operate.
■Lane departure alert function
The warning buzzer may be difficult to hear due to external noise, audio playback, etc.
Also, it may be difficult to feel steering wheel vibrations due to the road conditions, etc.

303
4
4-5. Using the driving support systems
Driving
GS450h_300h_OM_OM30F00E_(EE)
Dynamic radar cruise control
with full-speed
range
∗
In vehicle-to-vehicle distance control mode, the vehicle automatically acceler-
ates, decelerates and stops to match the speed changes of the preceding vehicle
even if the accelerator pedal is not depressed. In constant speed control mode,
the vehicle runs at a fixed speed.
Use the dynamic radar cruise control with full-speed range on freeways and
highways.
●Vehicle-to-vehicle distance control mode ( →P. 306)
●Constant speed control mode ( →P. 311)
Vehicle-to-vehicle distance button
Display
Set speed
Indicators
Cruise control switch
∗: If equipped
Summary of functions
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3044-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
WA R N I N G
■Before using dynamic radar cruise control with full-speed range
Driving safely is the sole responsibility of the driver. Do not rely solely on the system,
and drive safely by always paying ca reful attention to your surroundings.
The dynamic radar cruise control with full- speed range provides driving assistance to
reduce the driver’s burden. However, there are limitations to the assistance provided.
Even when the system is functioning norma lly, the condition of the preceding vehicle as
detected by the system may differ from the condition observed by the driver. There-
fore, the driver must always remain alert, as sess the danger of each situation and drive
safely. Relying on this system or assuming the system ensures safety while driving can
lead to an accident, resulting in death or serious injury.
■Cautions regarding the driving assist systems
Observe the following precautions, as there are limitations to the assistance provided
by the system.
Failure to do so may cause an accident resulting in death or serious injury.
●Assisting the driver to measure following distance
The dynamic radar cruise control with full-speed range is only intended to help the
driver in determining the fo llowing distance between the driver’s own vehicle and a
designated vehicle traveling ahead. It is not a mechanism that allows careless or inat-
tentive driving, and it is not a system that can assist the driver in low-visibility condi-
tions. It is still necessary for driver to pay close attention to the vehicle’s surroundings.
●Assisting the driver to judge proper following distance
The dynamic radar cruise control with full-speed range determines whether the fol-
lowing distance between the driver’s own vehicle and a designated vehicle traveling
ahead is within a set range. It is not capable of making any other type of judgement.
Therefore, it is absolutely necessary for the driver to remain vigilant and to determine
whether or not there is a possibility of danger in any given situation.
●Assisting the driver to operate the vehicle
The dynamic radar cruise control with full-speed range has limited capability to pre-
vent or avoid a collision with a vehicle trave ling ahead. Therefore, if there is ever any
danger, the driver must take immediate and direct control of the vehicle and act
appropriately in order to ensure the safety of all involved.
■To avoid inadvertent dynamic radar cruise control with full-speed range activation
Switch the dynamic radar cruise control with full-speed range off using the “ON/OFF”
button when not in use.