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3064-5. Using the driving support systems
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■Automatic cancelation of constant speed control mode
Constant speed control mode is automatica lly canceled in the following situations:
●Actual vehicle speed is more than approximately 16 km/h (10 mph) below the set vehi-
cle speed.
●Actual vehicle speed falls below approximately 40 km/h (25 mph).
●VSC is activated.
●TRC is activated for a period of time.
●When the VSC or TRC system is turned off by pressing the VSC OFF switch.
●Pre-crash braking is activated.
If constant speed control mode is automatically canceled for any other reason, there may be a malfunction in the system. Contact an y authorized Lexus retailer or Lexus autho- rized repairer, or any reliable repairer.
■Warning messages and buzzers for dynamic radar cruise control with full-speed range
Warning messages and buzzers are used to indicate a system malfunction or to inform the driver of the need for caution while driv ing. If a warning message is shown on the
multi-information display, read the message and follow the instructions. (P. 466)
■When the sensor may not be correctly detecting the vehicle ahead
In the case of the following and depending on the conditions, operate the brake pedal
when deceleration of the system is insufficient or operate the accelerator pedal when acceleration is required.As the sensor may not be able to correctly detect these types of vehicles, the approach
warning ( P. 303) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same lane
●Vehicles with small rear ends (trailers with no load on board, etc.)
●Motorcycles traveling in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the detecting of the sensor
Page 307 of 600
3074-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■Conditions under which the vehicle-to-vehicle distance control mode may not function correctly
In the case of the following conditions, operate the brake pedal (or accelerator pedal,
depending on the situation) as necessary. As the sensor may not be able to correctly detect vehicles ahead, the system may notoperate properly.
●When the vehicle ahead of you decelerates suddenly
●When your vehicle is pointing upwards(caused by a heavy load in the luggage com-partment, etc.)
●Preceding vehicle has an extremely highground clearance
●When the road curves or when the lanes arenarrow
●When steering wheel operation or your posi-tion in the lane is unstable
Page 461 of 600

4617-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
ABS warning light Indicates a malfunction in:•The ABS; or
• The brake assist system Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.
Electric power steering system warning light (warning buzzer)
Indicates a malfunction in the EPS (Electric Power Steering) sys- tem Have the vehicle inspected by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
(Flashes) (If equipped)
PCS (Pre-Crash Safety system) warning light
●When the warning light flashes (and a buzzer sounds):
Indicates a malfunction in the PCS (Pre-Crash Safety system) Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immedi-
ately.
●When the warning light flashes (and a buzzer does not sound):
Indicates that the PCS (Pre-Crash Safety system) is temporarily unavailable, possibly due to either of the following:• An area around the radar sensor or camera sensor being dirty
or covered with condensation, ice, stickers, etc. Clear the dirt, condensation, ice, stickers, etc. ( P. 264, 285)
• Radar sensor or camera sensor operational conditions (such as temperature etc.) being not met Driving is possible in this case. The PCS (Pre-Crash Safety
system) will be enabled if the operational conditions (such as temperature etc.) are met again.
●When the warning light is illuminated:Either the VSC (Vehicle Stability Control) system or PCS (Pre-Crash Safety system) is disabled or both are disabled.
To enable the PCS (Pre-Crash Safety system), enable both the VSC system and PCS (Pre-Crash Safety system). ( P. 281, 327)
Slip indicator
Indicates a malfunction in: • The VSC system;• The TRC system; or
• The hill-start assist control system Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.
The light will flash when the VSC, TRC or ABS system is operating.
Warning lightWarning light/Details/Actions
Page 469 of 600
4697-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
(If equipped)
Indicates a malfunction in the Lexus parking assist All assist-sensors flash.
A buzzer also sounds. Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer.
(If equipped)
Indicates that Lexus parking a ssist-sensor is dirty or cov- ered with ice
A buzzer also sounds. Clean the sensor.
Indicates an attempt was made to release the parking
brake with a door open or the front passenger’s seat belt unfastenedA buzzer also sounds.
Close all doors and fasten the front passenger’s seat belt before releasing the parking brake.
Warning messageDetails/Actions
(Flashes)
Page 476 of 600
4767-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
(If equipped)
Indicates that the radar sensor is dirty or covered with iceA buzzer also sounds.
Clean the sensor.
(If equipped)
Indicates that the dynamic radar cruise control system cannot be used temporarily due to bad weatherA buzzer also sounds.
Use the radar cruise control system when it becomes available again.
(If equipped)
Indicates that the radar cruise control system brake con-trol function is temporarily unavailable Depress the brake.
(If equipped)
Indicates that the grille shutter system cannot operate or the grille shutter is dirty or covered with ice
A buzzer also sounds. Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer.
Warning messageDetails/Actions
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4777-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
(Vehicles with entry function)
Indicates a malfunction in the smart entry & start system A buzzer also sounds.
Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliablerepairer.
(If equipped)
Indicates that a Blind Spot Monitor sensor or the sur-rounding area on the bumper is dirty or covered with ice
A buzzer also sounds. Clean the sensor and its surrounding area on the bumper.
Indicates a malfunction in the cruise control system ordynamic radar cruise control system (if equipped)Press the “ON/OFF” button once to deactivate the
system, and then press the button again to reactivate the system.A buzzer also sounds.
Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer.
(If equipped)
Indicates a malfunction in th e dynamic radar cruise con- trol with full-speed range
Depress the brake pedal. A buzzer also sounds. Have the vehicle inspected by any authorized Lexus
retailer or Lexus authorized repairer, or any reliable repairer.
Warning messageDetails/Actions
(Flashes)
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5077-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■When using the compact spare tire
●Remember that the compact spare tire provided is specifically designed for use with your vehicle. Do not use your compact spare tire on another vehicle.
●Do not use more than one compact spare tire simultaneously.
●Replace the compact spare tire with a standard tire as soon as possible.
●Avoid sudden acceleration, abrupt steerin g, sudden braking and shifting operations
that cause sudden engine braking.
■When the compact spare tire is attached
The vehicle speed may not be correctly detected, and the following systems may not
operate correctly:
■Speed limit when using the compact spare tire
Do not drive at speeds in excess of 80 km /h (50 mph) when a compact spare tire is installed on the vehicle.
The compact spare tire is not designed for driving at high speeds. Failure to observe this precaution may lead to an accid ent causing death or serious injury.
■After using the tools and jack
Before driving, make sure all the tools and jack are securely in place in their storage location to reduce the possibility of personal injury during a collision or sudden brak- ing.
• ABS & Brake assist
•VSC •TRC• Cruise control (if equipped)
• Dynamic radar cruise control with full- speed range (if equipped)• (Pre-Crash Safety system)
(if equipped) •EPS• AFS (if equipped)
• LDH (if equipped) • DRS (if equipped)
• Adaptive Variable Suspension system
(if equipped) • LKA (Lane-Keeping Assist) (if equipped)
• Tire pressure warning system (if equipped)•VDIM
• VGRS (if equipped) • Lexus parking assist monitor (if equipped)
• Lexus parking assist-sensor (if equipped)• Navigation system (if equipped)
Page 580 of 600

580What to do if... (Troubleshooting)
GS450h_300h_OM_OM30F92E_(EE)
●Is the window lock switch pressed?
The power window except for the one at the driver’s seat cannot be operated
if the window lock switch is pressed. ( P. 193)
●The auto power off function will be operated if the vehicle is left in ACCES-
SORY or ON mode (the hybrid system is not operating) for a period of time.
( P. 219)
●The seat belt reminder light is flashing
Are the driver and the front passenger wearing the seat belts? ( P. 462)
●The parking brake indicator is on
Is the parking brake released? ( P. 232)
Depending on the situation, other type s of warning buzzer may also sound.
( P. 460, 466)
●Did anyone inside the vehicle open a door or anything move inside the vehicle
during setting the alarm?
The sensor detects them and the alarm sounds. ( P. 91)
To stop the alarm, turn the power switch to ON mode or start the hybrid system.
●Is the electronic key left inside the vehicle or the moon roof opened (if
equipped)?
Check the message on the multi-information display. ( P. 466)
The windows do not open or close by operating the power window
switches
The power switch is turned off automatically
A warning buzzer sounds during driving
An alarm is activated and th e horn sounds (if equipped)
A warning buzzer sounds when leaving the vehicle
(vehicles with entry function)