2015 Lexus GS300h brake sensor

3144-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(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 not
operate 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 high
ground clearance
●When the road curves or when the lanes are
narrow
●When steering wheel operation or your posi-
tion in the lane is unstable

3184-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(EE)
This mode employs a radar sensor to detect the presence of vehicles up to
approximately 120 m (400 ft.) ahead, determines the current vehicle-to-vehicle
following distance, and operates 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 dis-
tance can also be set by operating the vehicle-to-vehicle distance button.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appears
When a vehicle is detected running ahead of you, the system automatically deceler-
ates your vehicle. When a greater reduction in vehicle speed is necessary, the system
applies the brakes (the stop lights will come on at this time). The system will respond to
changes in the speed of the vehicle ahead in order to maintain the vehicle-to-vehicle
distance set by the driver. Approach wa rning warns you when the system cannot
decelerate sufficiently to prevent your ve hicle from closing in on the vehicle ahead.
Example of acceleration
When there are no longer any preceding vehicles driving slower than the set
speed
The system accelerates until the set speed is reached. The system then returns to con-
stant speed cruising.
Driving in vehicle-to-vehicle distance control mode
1
2
3

3254-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F00E_(EE)
■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. 322) 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 (traile rs 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
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage com-
partment, etc.)
●Preceding vehicle has an extremely high
ground clearance

3264-5. Using the driving support systems
GS450h_300h_OM_OM30F00E_(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 not
operate properly.
●When the vehicle ahead of you decelerates suddenly
●When the road curves or when the lanes are
narrow
●When steering wheel operation or your posi-
tion in the lane is unstable

4777-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
ABS warning lightIndicates a malfunction in:
•The ABS; or
• The brake assist system
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
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 dealer or
repairer, or another duly qualified and equipped professional
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 dealer or
repairer, or another duly qualified and equipped professional
immediately.
●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. 263, 284, 292)
• Radar sensor or camera sensor being outside of its operational
condition range. (temperature etc.)
→ If operational condition (tempera ture etc.) is satisfied, PCS
(Pre-Crash Safety system) becomes to be available.
●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. 2 8 0 , 3 4 7 )
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 dealer or
repairer, or another duly qualified and equipped professional
immediately.
The light will flash when the VSC, TRC or ABS system is operating.
Warning lightWarning light/Details/Actions

4857-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
(If equipped)
Indicates a malfunction in the Lexus parking assistAll assist-sensors flash.
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
(If equipped)
Indicates that Lexus parking assist-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
unfastened
A buzzer also sounds.
→ Close all doors and fasten the front passenger’s seat
belt before releasing the parking brake.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)

4937-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(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 weather
A 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 shu tter 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
dealer or repairer, or another duly qualified and
equipped professional.
Wa r n i n g m e s s a g eDetails/Actions

4947-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
(Vehicles with entry function)
Indicates a malfunction in the smart entry & start systemA buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
(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 or
dynamic 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
dealer or repairer, or another duly qualified and
equipped professional.
(If equipped)
Indicates a malfunction in the 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
dealer or repairer, or another duly qualified and
equipped professional.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)