2015 Lexus GS450h warning

GS450h_OM_OM30E26U_(U)
2074-2. Driving procedures
4
Driving
■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 perfor mance, downshifting operation may some-
times be restricted. In some circumstances, downshifting 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 th e power switch is turned off after driving
in snow mode.
■If the shift lever cannot be shifted from P
 P. 5 5 6

GS450h_OM_OM30E26U_(U)
2134-2. Driving procedures
4
Driving
■When there is a malfunction in the system
Warning lights and/or warning message will turn on or flash. (P. 505, 518)
Depending on the condition, the parking brake indicator light may flash.
■Usage in winter time
 P. 3 2 0
NOTICE
■When parking the vehicle
Before you leave the vehicle, set the parking brake, shift the shift lever to P and
make sure that the vehicle does not move.
■When the system malfunctions
Stop the vehicle in a safe place and check the warning messages.
■When the parking brake cannot be released due to a malfunction
Use the parking brake release tool to manually release the parking brake.
( P. 5 5 7 )
Driving the vehicle with the parking brake set will lead to brake components over-
heating, which may affect braking performance and increase brake wear.

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GS450h_OM_OM30E26U_(U)
4-2. Driving procedures
Brake Hold
Turns the brake hold system on
The brake hold standby indicator
(green) comes on. While the system is
holding the brake, the brake hold
operated indicator (yellow) comes on.
■Brake hold system operating conditions
The brake hold system cannot be turn ed on in the following conditions:
●The trunk or hood is not closed.
●The driver’s door is not closed.
●The driver is not wearing the seat belt.
If any of the conditions above are detected when the brake hold system is enabled,
the system will turn off and the brake hold standby indicator light will go off. In addi-
tion, if any of the conditions are detected while the system is holding the brake, a
warning buzzer will sound and a message wi ll be shown on the multi-information dis-
play. The parking brake will then be set automatically.
■Brake hold function
●If the brake pedal is left released for a period of about 3 minutes after the system
has started holding the brake, the parking brake will be set automatically. In this
case, a warning buzzer sounds and a message is shown on the multi-information
display.
●To turn the system off while the system is holding the brake, firmly depress the
brake pedal and press the button again.
●The brake hold function may not hold the vehicle when the vehicle is on a steep
incline. In this situation, it may be nece ssary for the driver to apply the brakes. The
multi-information display will info rm the driver of this situation.
The brake hold system keeps the brake applied when the shift lever is in
D, S or N with the system on and the brake pedal has been depressed to
stop the vehicle. The system releases the brake when the accelerator
pedal is depressed with the shift lever in D or S to allow smooth start off.

GS450h_OM_OM30E26U_(U)
2154-2. Driving procedures
4
Driving
■When the parking brake is set automatically while the system is holding the brakes
The parking brake will not be released automatically. Release the parking brake by
operating the parking brake switch, making sure that the parking brake indicator
light goes off. ( P. 211)
■When there is a malfunction in the system
Warning lights and/or warning mess ages will turn on or flash. (P. 505, 517)
CAUTION
■When the vehicle is on a steep incline
When using the brake hold system on a steep incline exercise caution. The brake
hold function may not hold th e vehicle in such a situation.
■When stopped on a slippery road
The system cannot stop the vehicle when the gripping ability of the tires has been
exceeded. Do not use the system wh en stopped on a slippery road.
NOTICE
■When parking the vehicle
The brake hold system is not designed for use when parking the vehicle for a long
period of time. Turning the power switch off while the system is holding the brake
may release the brake, which would cause the vehicle to move. When operating
the power switch, depress the brake pedal, set the parking brake and shift the shift
lever to P.

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GS450h_OM_OM30E26U_(U)
4-5. Using the driving support systems
■Cruise control can be set when
●The shift lever is in D or range 4 or higher of S has been selected.
●Range 4 or higher of D has been selected by using the paddle shift.
●Vehicle speed is above approximately 25 mph (40 km/h).
■Accelerating after setting the vehicle speed
●The vehicle can be accelerated normally. After acceleration, the set speed
resumes.
●Even without canceling the cruise control, the set speed can be increased by first
accelerating the vehicle to the desired speed and then pushing the lever down to
set the new speed.
■Automatic cruise control cancelation
Cruise control will stop maintaining the vehicle speed in any of the following situa-
tions.
●Actual vehicle speed falls more than approximately 10 mph (16 km/h) below the
preset vehicle speed.
At this time, the memorized set speed is not retained.
●Actual vehicle speed is below approximately 25 mph (40 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is turn ed off by pressing the VSC OFF switch.
■If the warning message for the cruise control is shown on the multi-information dis-
play
Press the “ON/OFF” button once to deacti vate the system, and then press the but-
ton again to reactivate the system.
If the cruise control speed cannot be set or if the cruise control cancels immediately
after being activated, there may be a malfunction in the cruise control system. Have
the vehicle inspected by your Lexus dealer.

GS450h_OM_OM30E26U_(U)
2454-5. Using the driving support systems
4
Driving
This mode employs a radar sensor to detect the presence of vehicles up to
approximately 400 ft. (120 m) ahead, determines the current vehicle-to-
vehicle following distance, and opera tes to maintain a suitable following
distance from the vehicle ahead.
Note that vehicle-to-vehicle distance will close in when traveling on long downhill
slopes.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle
distance can also be set by operating the vehicle-to-vehicle distance control.
Example of deceleration cruising
When the vehicle ahead is driving slower than the set speed
When a vehicle is detected running ahead of you, the system automatically decel-
erates your vehicle. When a greater reduction in vehicle speed is necessary, the
system applies the brakes. A warning tone warns you when the system cannot
decelerate sufficiently to prevent your vehicle from closing in on the vehicle
ahead.
Driving in vehicle-to-vehicle distance control mode
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GS450h_OM_OM30E26U_(U)
4-5. Using the driving support systems
Example of follow-up cruising
When following a vehicle driving slower than the set speed
The system continues follow-up cruising while adjusting for changes in the speed
of the vehicle ahead in order to maintain the vehicle-to-vehicle distance set by the
driver.
Example of acceleration
When there are no longer any vehi cles ahead driving slower than the
set speed
The system accelerates until the set speed is reached. The system then returns to
constant speed cruising.
When your vehicle is too close to a vehicle ahead, and sufficient auto-
matic deceleration via the cruise co ntrol is not possible, the display will
flash and the buzzer will sound to alert the driver. An example of this
would be if another driver cuts in front of you while you are following a
vehicle. Apply the brakes to ensure an appropriate vehicle-to-vehicle dis-
tance.
■Warnings may not occur when
In the following instance s, there is a possibility that the warnings will not
occur:
●When the speed of the vehicle ahea d matches or exceeds your vehi-
cle speed
●When the vehicle ahead is traveling at an extremely slow speed
●Immediately after the cruise control speed was set
●At the instant the accelerator is applied
Approach warning
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4

GS450h_OM_OM30E26U_(U)
2494-5. Using the driving support systems
4
Driving
■Automatic cancelation of constant speed control
The cruise control will stop maintaining the vehicle speed in the following situations:
●Actual vehicle speed is more than approximately 10 mph (16 km/h) below the set
vehicle speed.
At this time, the memorized set speed is not retained.
●Vehicle speed falls below approximately 25 mph (40 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is turned off by pressing the VSC OFF switch.
■When the LKA (Lane-Keeping Assist) will be activated
Using the radar cruise control in vehicle-to-vehicle distance control mode, lane
keeping assist function is activated.
■Radar sensor and grille cover
Always keep the sensor and grille cover clean to ensure that the vehicle-to-vehicle
distance control operates properly. (Some ob structions, such as snow, ice and plastic
objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control is cance led if an obstruction is detected.
■Warning messages and buzzers for dynamic radar cruise control
Warning messages and buzzers are used to indicate a system malfunction or to
inform the driver of the need for caution while driving. ( P. 5 1 5 )
Grille cover
Radar sensor
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