
2724-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■Pre-crash braking*3
●When the pre-crash braking function is operating, a large amount of braking force will be applied.
●If the vehicle is stopped by the operation of the pre-crash braking function, the pre-crash braking function operation will be canceled after approximately 2 seconds.Depress the brake pedal as necessary.
●The pre-crash braking function may not operate if certain operations are performedby the driver. If the accelerator pedal is being depressed strongly or the steeringwheel is being turned, the system may determine that the driver is taking evasive 
action and possibly prevent the pre-crash braking function from operating.
●In some situations, while the pre-crash braking function is operating, operation of thefunction may be canceled if the accelerator pedal is depressed strongly or the steer-
ing wheel is turned and the system determines that the driver is taking evasive action.
●If the brake pedal is being depressed, the system may determine that the driver is tak-ing evasive action and possibly delay the operation timing of the pre-crash braking
function.
*3: Depending on the region in which the vehicle was sold, the pre-crash braking func-
tion may not be available.
■When to disable the pre-crash safety system 
In the following situations, disable the system, as it may not operate properly, possibly
leading to an accident resulting in death or serious injury:
●When the vehicle is being towed
●When your vehicle is towing another vehicle
●When transporting the vehicle via truck, boat, train or similar means of transportation
●When the vehicle is raised on a lift with the hybrid system on and the tires are allowed to rotate freely
●When inspecting the vehicle using a drum tester such as a chassis dynamometer orspeedometer tester, or when using an on vehicle wheel balancer
●When a strong impact is applied to the front bumper or front grille, due to an accident
or other reasons
●If the vehicle cannot be driven in a stable manner, such as when the vehicle has beenin an accident or is malfunctioning
●When the vehicle is driven in a sporty manner or off-road
●When the tires are not properly inflated
●When the tires are very worn
●When tires of a size other than specified are installed
●When tire chains are installed
●When a compact spare tire or an emergency tire puncture repair kit is used
●If equipment (snow plow, etc.) that may obstruct the radar sensor or camera sensor istemporarily installed to the vehicle 

2804-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE) 
• After the hybrid system has started the vehicle has not been driven for a certain amount of time• While making a left/right turn and for a  few seconds after making a left/right turn 
• While driving on a curve and for a few seconds after driving on a curve • If your vehicle is skidding 
• If the wheels are misaligned • If a wiper blade is blocking the camera sensor 
• The vehicle is wobbling. • The vehicle is being driven at extremely high speeds.• When driving on a hill  
• If the radar sensor or camera sensor is misaligned
●In some situations such as the following,  sufficient braking force may not be obtained, 
preventing the system from performing properly: 
• If the braking functions cannot operate to their full extent, such as when the brake parts are extremely cold, extremely hot, or wet 
• If the vehicle is not properly maintained (brakes or tires are excessively worn, improper tire inflation pressure, etc.)• When the vehicle is being driven on a gravel road or other slippery surface
●Some pedestrians such as the following may not be detected by the radar sensor and 
camera sensor, preventing the system from operating properly*4: 
• Pedestrians shorter than approximately 1 m (3 .2 ft.) or taller than approximately 2 m 
(6.5 ft.) • Pedestrians wearing oversized clothing (a rain  coat, long skirt, etc.), making their sil- houette obscure 
• Pedestrians who are carrying large baggage, holding an umbrella, etc., hiding part of their body• Pedestrians who are bending forward or squatting 
• Pedestrians who are pushing a stroller , wheelchair, bicycle or other vehicle • Groups of pedestrians which are close together• Pedestrians who are wearing white and look extremely bright 
• Pedestrians in the dark, such as at night or while in a tunnel • Pedestrians whose clothing appears to be nearly the same color or brightness astheir surroundings 
• Pedestrians near walls, fences, guardrails, or large objects • Pedestrians who are on a metal object (manhole cover, steel plate, etc.) on the road• Pedestrians who are walking fast 
• Pedestrians who are changing speed abruptly • Pedestrians running out from be hind a vehicle or a large object • Pedestrians who are extremely close to the side of the vehicle (outside rear view 
mirror, etc.) 
• If the front of the vehicle is raised or low- ered 

2854-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■Before using LKA system 
Do not rely solely upon the LKA system. Th e LKA system does not automatically drive the vehicle or reduce the amount of attention that must be paid to the area in front of 
the vehicle. The driver must always assume  full responsibility for driving safely by pay- ing careful attention to the surrounding conditions and operating the steering wheel tocorrect the path of the vehicle. Also, the driver must take adequate breaks when 
fatigued, such as from driving for a long period of time. Failure to perform appropriate driving operat ions and pay careful attention may lead to an accident, resulting in death or serious injury.
■To avoid operating LKA system by mistake 
When not using the LKA system, use the LKA switch to turn the system off.
■Situations unsuitable for LKA system 
Do not use the LKA system in the following situations. The system may not operate properly and le ad to an accident, resulting in death or serious injury.
●A spare tire, tire chains, etc. are equipped.
●When the tires have been excessively worn, or  when the tire inflation pressure is low.
●Tires which differ by structure, manufacturer, brand or tread pattern are used.
●Objects or patterns that could be mistaken for white (yellow) lines are present on the side of the road (guardrails, cu rbs, reflective poles, etc.).
●Vehicle is driven on a snow-covered road.
●White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.
●Asphalt repair marks, white (yellow) line marks, etc. are present due to road repair.
●Vehicle is driven in a temporary lane or restricted lane due to construction work.
●Vehicle is driven on a road surface which is slippery due to rainy weather, fallen snow, freezing, etc.
●Vehicle is driven in traffic lanes other than on highways and freeways.
●Vehicle is driven in a construction zone.
●Vehicle is towing a trailer or another vehicle. (vehicles with towing package)
■Preventing LKA system malfunctions and operations performed by mistake
●Do not modify the headlights or place stickers, etc. on the surface of the lights.
●Do not modify the suspension etc. If the  suspension etc. needs to be replaced, con- tact any authorized Lexus retailer or Le xus authorized repairer, or any reliable 
repairer.
●Do not install or place anything on the hood  or grille. Also, do not install a grille guard (bull bars, kangaroo bar, etc.).
●If your windshield needs repairs, contac t any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer. 

2904-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
●The vehicle is driven on a road which tilts left or right, or a winding road.
●The vehicle is driven on an unpaved or rough road.
●The vehicle is driven around a sharp curve.
●The traffic lane is excessively narrow or wide.
●The vehicle is extremely tilted due to carrying heavy luggage or having improper tire pressure.
●The distance to the preceding vehicle is extremely short.
●The vehicle is moving up and down a large amount due to road conditions during driv-ing (poor roads or road seams).
●The headlight lenses are dirty and emit a faint  amount of light at night, or the beam axis has deviated.
●The vehicle is struck by a crosswind.
●The vehicle has just changed lanes or crossed an intersection.
●Snow tires, etc. are equipped.
■Warning message 
Warning messages are used to indicate a syst em malfunction or to inform the driver of the need for caution while driving. ( P. 466)
■Customization 
The following settings can be changed. 
For how to change settings, refer to P. 561.
FunctionSetting details
Lane departure alert functionAdjust alert sensitivity
Adjust alert type
Steering assist functionTurn steering wheel assistance on and off
Vehicle sway warning functionTurn function on and off
Adjust alert sensitivity
Lane centering functionTurn function on and off 

3294-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■Automatic system cancelation of hill-start assist control 
The hill-start assist control will be canc eled in any of the following situations;
●The shift lever is shifted to N or P.
●The accelerator pedal is depressed.
●The parking brake is engaged.
●Approximately 2 seconds elapse after the brake pedal is released.
■Operating conditions of emergency brake signal 
When the following three conditions are me t, the emergency brake signal will operate:
●The emergency flashers are off.
●Actual vehicle speed is over 55 km/h (35 mph).
●The brake pedal is depressed in a manner that cause the system to judge from the vehi- cle deceleration that this is a sudden braking operation.
■Automatic system cancelation of emergency brake signal 
The emergency brake signal will turn of f in any of the following situations:
●The emergency flashers are turned on.
●The brake pedal is released.
●The system judges from the vehicle deceleration that is not a sudden braking operation.
WARNING
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded (such as excessively 
worn tires on a snow covered road).
●The vehicle hydroplanes while driving at  high speed on wet or slick roads.
■Stopping distance when the ABS is operating may exceed that of normal conditions 
The ABS is not designed to shorten the vehicle’s stopping distance. Always maintain a safe distance from the vehicle in front of  you, especially in the following situations:
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or uneven surfaces
■TRC may not operate effectively when 
Directional control and power may not be  achievable while driving on slippery road surfaces, even if the TRC system is operating.  
Drive the vehicle carefully in conditions  where stability and power may be lost.
■Hill-start assist control does not operate effectively when
●Do not overly rely on the hill-start assist control. The hill-start assist control may not 
operate effectively on steep inclines and roads covered with ice.
●Unlike the parking brake, hill-start assist co ntrol is not intended to hold the vehicle stationary for an extended period of time. Do not attempt to use hill-start assist con- 
trol to hold the vehicle on an incline, as doing so may lead to an accident. 

3304-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■When the VSC is activated 
The slip indicator light flashes. Always  drive carefully. Reckless driving may cause an accident. Exercise particular care when the indicator light flashes.
■When the TRC/VSC systems are turned off 
Be especially careful and drive at a speed appropriate to the road conditions. As these are the systems to help ensure vehicle stability and driving force, do not turn the TRC/ 
VSC systems off unless necessary.
■Replacing tires 
Make sure that all tires are of the specified size, brand, tread pattern and total load 
capacity. In addition, make sure that the tires are inflated to the recommended tire infla- tion pressure level. 
The ABS, TRC and VSC systems will not function  correctly if different tires are installed 
on the vehicle. Contact any authorized Lexus retailer or  Lexus authorized repairer, or any reliable repairer for further information when replacing tires or wheels.
■Handling of tires and the suspension 
Using tires with any kind of problem or modi fying the suspension will affect the driving assist systems, and may cause  a system to malfunction. 

3324-6. Driving tips
GS450h_300h_OM_OM30F92E_(EE)
◆Delays 
Repeated acceleration and deceleration, as well as long waits at traffic lights, 
will lead to bad fuel economy. Check traffic reports before leaving and avoid 
delays as much as possible. When driving in a traffic jam, gently release the 
brake pedal to allow the vehicle to move forward slightly while avoiding over- 
use of the accelerator pedal. Doing so can help control excessive gasoline 
consumption.
◆Highway driving 
Control and maintain the vehicle at a constant speed. Before stopping at a toll 
booth or similar, allow plenty of time to release the accelerator and gently 
apply the brakes. A greater amount of electrical energy can be regenerated 
when slowing down.
◆Air conditioning 
Use the air conditioning only when necessary. Doing so can help reduce 
excessive gasoline consumption. 
In summer: When the ambient temperature is high, use the recirculated air 
mode. Doing so will help to reduce the burden on the air conditioning system 
and reduce fuel consumption as well. 
In winter: Because the gasoline engine will not automatically cut out until it 
and the interior of the vehicle are warm, it will consume fuel. Also, fuel con- 
sumption can be improved by avoiding overuse of the heater.
◆Checking tire inflation pressure 
Make sure to check the tire inflation pressure frequently. Improper tire infla- 
tion pressure can cause poor fuel economy. 
Also, as snow tires can cause large amounts of friction, their use on dry roads 
can lead to poor fuel economy. Use ti res that are appropriate for the season. 

3344-6. Driving tips 
GS450h_300h_OM_OM30F92E_(EE)
Winter driving tips
●Use fluids that are appropriate to the prevailing outside temperatures.  
•Engine oil 
• Engine/power control unit coolant 
•Washer fluid
●Have a service technician inspect the condition of the 12-volt battery.
●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 specified size and brand, and that chains match the size of the tires.
*: Tire chains cannot be mounted on vehicles with front and rear tires of differing 
sizes and vehicles with LDH and 19 inch tires
Perform the following according to the driving conditions: 
●Do not try to forcibly open a window or move a wiper that is frozen. Pour 
warm water over the frozen area to melt the ice. Wipe away the water imme- 
diately 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. 
●Check for and remove any excess ice or snow that may have accumulated on
the exterior lights, vehicle’s roof, chassis, around the tires or on the brakes.
●Remove any snow or mud from the bottom of your shoes before getting in the 
vehicle.
Carry out the necessary preparations an d inspections before driving the vehi- 
cle in winter. Always drive the vehicle in a manner appropriate to the prevail- 
ing weather conditions. 
Preparation for winter
Before driving the vehicle