Transmission Lexus IS250 2010 Owner's Guide

177
2-4. Using other driving systems
2
When driving
IS350/250_U
■Cruise control can be set when
●Vehicles with an automatic transmission: the shift lever is in the D position or S
position. However, it cannot be set if any of the ranges 1 through 3 has been
selected.
●Vehicle speed is more than approximately 25 mph (40 km/h).
■Accelerating
The vehicle can be accelerated normally. After acceleration, the set speed
resumes.
■Automatic cruise control cancellation
The set speed is automatically cancelled in any of the following situations.
●Actual vehicle speed falls more than 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 25 mph (40km/h)
●VSC is activated
■If the cruise control indicator light flashes
Turn the “ON-OFF” button off once, and then 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.

196
2-4. Using other driving systems
IS350/250_U
Driving assist systems
To help enhance driving safety and performance, the following systems
operate automatically in response to various driving situations. Be aware,
however, that these systems are supplementary and should not be relied
upon too heavily when operating the vehicle.
■ ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if
the brakes are applied while driving on a slippery road surface.
■Brake assist
Generates an increased level of braking force after the brake pedal is
depressed, when the system detects a panic stop situation.
■VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or turning on
slippery road surfaces.
■TRAC (Traction Control)
Maintains drive power and prevents the rear wheels (2WD models) or all
wheels (AWD models) from spinning wh en starting the vehicle or acceler-
ating on slippery roads.
■ Hill-start assist control (vehicles with an automatic transmission)
Prevents the vehicle from rolling backwards when starting on an incline or
slippery slope.
■EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel.

201
2-4. Using other driving systems
2
When driving
IS350/250_U
CAUTION
■TRAC may not operate effectively when
Directional control and power may not be achievable while driving on slippery road
surfaces, even if the TRAC system is operating.
Do not drive the vehicle in conditions where stability and power may be lost.
■If hill-start assist control does not operate effectively
(vehicles with an automatic transmission)
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 in ice.
■When the VSC is activated
The slip indicator light flashes and a warning buzzer sounds. Always drive carefully.
Reckless driving may cause an accident. Exercise particular care when the indica-
tor light flashes and a buzzer sounds.
■When TRAC and VSC are off
Be especially careful and drive at a speed appropriate to the road conditions. As
these are systems to ensure vehicle stability and driving force, do not turn off TRAC
and VSC 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
pressure level.
The ABS and VSC systems will not function correctly if different tires are fitted on
the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels.
■Handling of tires and suspension
Using tires with any kind of problem or modifying the suspension will affect the driv-
ing assist systems, and may cause the system to malfunction.

211
2-5. Driving information
2
When driving
IS350/250_U
Selecting tire chainsTire chains can be mounted on 16- and 17-inch tires. They cannot be
mounted on 18-inch tires. Use the correct tire chain size when mounting
the tire chains. Chain size is regulated for each tire size. Side chain
(0.12 in. [3 mm] in diameter)
Cross chain
(0.16 in. [4 mm] in diameter)
Regulations on the use of tire chains
● Regulations regarding the use of tire chains vary according to location
and type of road. Always check local regulations before installing
chains.
● Install the chains on the rear tires.
● Retighten the chains after driving 1 /4  1 /2 mile (0.5  1.0 km).
■When driving the vehicle
Accelerate the vehicle slowly and drive at a reduced speed suitable
to road conditions.
■ When parking the vehicle
Park the vehicle and move the shift lever to P (automatic transmis-
sion) or 1 or R (manual transmission) without setting the parking
brake. The parking brake may freeze up, preventing it from being
released. If necessary, block the wheels to prevent inadvertent slid-
ing or creeping.

215
2-5. Driving information
2
When driving
IS350/250_U
Dinghy towing (vehicles with an automatic transmission)
NOTICE
■To avoid serious damage to your vehicle
Do not tow your vehicle with four wheels on the ground.
Your vehicle is not designed to be dinghy towed (with 4 wheels on the
ground) behind a motor home.

216
2-5. Driving information
IS350/250_U
Dinghy towing (vehicles with a manual transmission)
Towing your vehicle with 4 wheels on the groundTo prevent damage to your vehicle, perform the following procedures
before towing. Shift the shift lever to neutral.
Switch to ACCESSORY mode. ( →P. 1 3 6 )
Ensure that the audio system and other powered devices have been
turned off.
Release the parking brake.
After towing, leave the engine in idle for at least 3 minutes before driv-
ing the vehicle.
■Necessary equipment and accessories
Specialized equipment and accessories are required for dinghy towing. Contact
the service branch of the motor home manufacturer regarding recommended
equipment.
Your vehicle can be dinghy towed in a forward direction (with 4 wheels on
the ground) behind a motor home.
STEP1
STEP2
STEP3

348
3-7. Other interior features
IS350/250_U
Seat heaters∗
Vehicles with an automatic transmissionHeats the seats
The indicator light comes on.
The higher the number, the
warmer the seats become.
Driver’s
seatFront
passenger’s
seat
∗: If equipped

349
3-7. Other interior features
3
Interior features
IS350/250_U
■The seat heaters can be used when
The “ENGINE START STOP” switch is in IGNITION ON mode.
■When not in use
Set the dial to “0”. The indicator light turns off.
Vehicles with a manual transmissionHeats the seats
The indicator light comes on.
The higher the number, the
warmer the seats become.Front
passenger’s
seat
Driver’s
seat

351
3-7. Other interior features
3
Interior features
IS350/250_U
Seat heaters and ventilators∗
The seat heaters and ventilators heat the seats and maintain good airflow
by blowing air from the seats.
Vehicles with an automatic transmissionHeats the seats
The indicator light (amber)
comes on.
The higher the number, the
warmer the seats become.
Blows air from the seats
The indicator light (green)
comes on.
The higher the number, the
stronger the airflow becomes.
Front
passenger’s
seat
Driver’s
seat
∗: If equipped

352
3-7. Other interior features
IS350/250_U
■The seat heaters and ventilators can be used when
The “ENGINE START STOP” switch is in IGNITION ON mode.
■When not in use
Set the dial to “0”. The indicator light turns off.
Vehicles with a manual transmissionHeats the seats
The indicator light (amber)
comes on.
The higher the number, the
warmer the seats become.
Blows air from the seats
The indicator light (green)
comes on.
The higher the number, the
stronger the airflow becomes.
Front
passenger’s
seat
Driver’s
seat