2015 Lexus IS250 cruise control

2034-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
■Radar sensor and grille cover
Always keep the sensor and grille cover clean to ensure that the vehicle-to-vehicle dis-
tance control operates properly. (Some obstructions, such as snow, ice and plastic
objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control is cancel ed if an obstruction is detected.
■Operation guide display
When the dynamic radar cruise control switch is operated, a guidance display is shown
on the meters for a few seconds as to how to operate the dynamic radar cruise control
switch or distance switch. ( P. 8 9 )
■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 fo r caution while driving. (P. 4 76 )
Grille cover
Radar sensor
1
2

2054-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
CAUTION
■Before using dynamic radar cruise control
Do not overly rely on vehicle-to-vehicle distance control.
Be aware of the set speed. If automatic deceleration/acceleration is not appropriate,
adjust the vehicle speed, as well as the distance between your vehicle and vehicles
ahead by applying the brakes etc.
■Cautions regarding the driving assist systems
Observe the following precautions.
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 is only intended to help the driver in determining
the following distance between the driver’s own vehicle and a designated vehicle
traveling ahead. It is not a mechanism that al lows careless or inattentive driving, and it
is not a system that can assist the driver in low-visibility conditions. 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 determines whether the following distance
between the driver’s own vehicle and a designated vehicle traveling ahead is appro-
priate or not. It is not capable of making an y 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 has no capa bility to prevent or avoid a collision with
a vehicle traveling ahead. Therefore, if there is ever any danger, the driver must take
immediate and direct control of the vehicl e and act appropriately in order to ensure
the safety of all involved.
■To avoid inadvertent cruise control activation
Switch the cruise control off using th e “ON/OFF” button when not in use.

2064-5. Using the driving support systems
IS350/250_U (OM53C50U)
CAUTION
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate speed control and could cause an accident result-
ing in death or serious injury.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as thos e covered with rain, ice or snow
●On steep downhills, or where there are sudden changes between sharp up and down
gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
●At entrances to expressways
●When weather conditions are bad enough that they may prevent the sensors from
functioning correctly (fog, snow , sandstorm, heavy rain, etc.)
●When an approach warning buzzer is heard often
●During emergency towing
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are in front of
you.
As the sensor may not be able to correctly detect these types of vehicles, the approach
warning (P. 201) will not be activated, and a fatal or serious accident may result.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving
●Vehicles with small rear ends (trailers with no load on board etc.)
●Motorcycles traveling in the same lane
■Conditions under which the vehicle-to-vehicle distance control may not function cor-
rectly
Apply the brakes as necessary in the following conditions as the radar sensor may not
be able to correctly detect vehicles ahead, and a fatal or serious accident may result:
●When water or snow thrown up by the surrounding vehicles hinders the functioning
of the sensor
●When your vehicle is pointing upwards (caused by a heavy load in the trunk etc.)
●When the road curves or when the lanes are narrow
●When steering wheel operation or your position in the lane is unstable
●When the vehicle ahead of you decelerates suddenly

2074-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
CAUTION
■Handling the radar sensor
Observe the following to ensure the cruise control system can function effectively.
Otherwise, the system may not function correctly and could result in an accident.
●Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover with a soft cloth so you do not mark or damage
them.
●Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off positi on, the system may malfunction. If the sen-
sor or surrounding area is subject to a stro ng impact, always have the area inspected
and adjusted by your Lexus dealer.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to the sensor, grille cover or surrounding area.
●Do not modify or paint the sensor and grille cover.
●Do not replace them with non-genuine parts.

4758-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
Indicates that the vehicle is being driven at 3 mph (5 km/
h) or more with the parking brake still engaged. A buzzer also sounds.
 Release the parking brake.
Indicates that the shift lever was used to attempt to shift
to the first gear position in M mode on a slippery road
surface
The gear position will not sh ift from the second gear.
A buzzer also sounds.
 Drive the vehicle in the second or a higher gear
position.
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
Indicates a malfunction in:
• The ABS; or
• The brake assist system
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
Indicates that the engine coolant temperature is too high
A buzzer also sounds.
 P. 5 0 6
(If equipped)
Indicates that the radar sensor is dirty or covered with
ice
A buzzer also sounds.
 Clean the sensor.
(If equipped)
Indicates that the dynamic radar cruise control system is
unable to judge vehicle-to-vehicle distance
A buzzer also sounds.
 Tu r n o f f s n o w m o d e .
If the windshield wipers are on, turn them off or set
them to a mode other than AUTO or high speed
wiper operation.
Wa r n i n g m e s s a g eDetails/Actions
(U.S.A.) (Canada) (Flashes)
(U.S.A.) (Canada)

4768-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
(If equipped)
Indicates that the LDA (Lane Departure Alert) system is
suspended (The camera sensor temperature is higher
than the operation temperature range)
A buzzer also sounds.
 Restart the LDA after driving for a while.
(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
• The 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 your Lexus dealer.
(If equipped)
Indicates a malfunction in the LDA (Lane Departure
Alert) system
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
(If equipped)
Indicates a malfunction in the PCS (Pre-Collision Sys-
tem)
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
(If equipped)
Indicates a malfunction in the BSM (Blind Spot Monitor)
system
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
Indicates abnormal engine oil pressure
A buzzer also sounds.
 Immediately stop the vehicle in a safe place and
contact your Lexus dealer.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)

4818-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
■Wa r n i n g m e s s a g e s
The warning message illustrations used are intended as examples, and may differ from
the image that is actua lly displayed on the multi-information display.
■Warning message in radar cruise mode (if equipped)
In the following situations, the warning messag e may not be displayed even if vehicle-to-
vehicle distance decreases:
●When your vehicle and the vehicle ahead are traveling at the same speed or the vehicle
ahead is traveling more quickly than your vehicle
●When the vehicle ahead is traveling at a very low speed
●Immediately after cruise control speed is set
●At the instant the accelerator pedal is depressed
■The LDA (Lane Departure Alert) lane departure warning function (if equipped)
In the following situations, the warning messag e will not be displayed even if a lane line is
crossed.
●When the vehicle speed deviates from the operating range of the LDA system func-
tions
●When the lane lines cannot be recognized
■Reset the maintenance data (U.S.A. only)
Make sure to reset the oil change system. ( P. 4 0 3 )
■Conditions that the tire pressure warning system may not function properly
 P. 4 2 8
■Warning buzzer
P. 4 6 9

4958-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
CAUTION
■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 tires simultaneously.
●Replace the compact spare tire with a standard tire as soon as possible.
●Avoid sudden acceleration, ab rupt steering, 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:
Also, not only can the following system not be utilized fully, but it may even negatively
affect the drive-train components:
•AWD system
■Speed limit when using the compact spare tire
Do not drive at speeds in excess of 50 mph (80 km/h) 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 accident 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.
NOTICE
■Driving with tire chains and the compact spare tire
Do not fit tire chains to the compact spare tire.
Tire chains may damage the vehicle body and adversely affect driving performance.
■When replacing the tires
When removing or fitting the wheels, tires or the tire pressure warning valve and trans-
mitter, contact your Lexus dealer as the tire pressure warning valve and transmitter
may be damaged if not handled correctly.
• ABS & Brake assist
•VSC
•TRAC
• Cruise control (if equipped)
• Dynamic radar cruise control
(if equipped)
• PCS (if equipped)
•EPS • Adaptive Variable Suspension System
(if equipped)
• LDA (Lane Departure Alert)
(if equipped)
• VGRS (if equipped)
• Rear view monitor system (if equipped)
• Intuitive parking assist (if equipped)
• Navigation system (if equipped)