2010 Lexus IS250 transmission

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