2008 Lexus IS250 automatic transmission

175
2-4. Using other driving systems
2
When driving
08_IS350/250_U_(L/O_0708)
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)
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
there 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 same 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.

184
2-5. Driving information
08_IS350/250_U_(L/O_0708)
Selecting snow chainsSnow chains can be mounted on 16- and 17-inch tires. They cannot be
mounted on 18-inch tires. Use the correct snow chain size when mount-
ing the snow chains. Chain size is regulated for each tire sizes. Side chain
(0.12 in. [3 mm] in diameter)
Cross chain
(0.16 in. [4 mm] in diameter)
Regulations on the use of snow 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 R (manual transmission) without setting the parking brake.
The parking brake may freeze up, preventing it from being released.

188
2-5. Driving information
08_IS350/250_U_(L/O_0708)
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.

251
3-5. Other interior features
3
Interior features
08_IS350/250_U_(L/O_0708)
Seat heaters (if equipped)
■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 an automatic transmissionHeats the seats
The indicator light comes on.
The higher the number, the
warmer the seats become.
Vehicles with a manual transmissionHeats the seats
The indicator light comes on.
The higher the number, the
warmer the seats become.
Driver’s
seatFront
passenger’s
seat
Driver’s
seat Front
passenger’s
seat

253
3-5. Other interior features
3
Interior features
08_IS350/250_U_(L/O_0708)
Seat heaters and ventilators (if equipped)
■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.
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 (red) 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.
Vehicles with a manual transmissionHeats the seats
The indicator light (red) 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.
Driver’s
seatFront
passenger’s
seat
Driver’s
seat Front
passenger’s
seat

283
4-2. Maintenance
4
Maintenance and care
08_IS350/250_U_(L/O_0708)
Vehicle interior
ItemsCheck points
Accelerator pedal• Moves smoothly (without uneven pedal effort or catching)?
Automatic transmission “Park”
mechanism• Can the vehicle be hold securely on an incline with the shift lever in
P?
Brake pedal
• Moves smoothly?
• Does it have appropriate clearance and correct amount of free play?
Brakes
• Not pull to one side when applied?
• Loss of brake effectiveness?
• Spongy feeling brake pedal?
• Pedal almost touches floor?
Head restraints• Move smoothly and lock securely?
Indicators/buzzers•Function properly?
Lights
• Do all the lights come on?
• Headlights aimed correctly? (
→P. 3 4 1 )
Pa r k i n g b r a ke
• Moves smoothly?
• Can hold the vehicle securely on an incline?
Seat belts
• Does the seat belt system operate smoothly?
• Are the belts undamaged?
Seats• Do the seat controls operate prop- erly?

339
4-3. Do-it-yourself maintenance
4
Maintenance and care
08_IS350/250_U_(L/O_0708)
FuseAmpereCircuit
13FR DOOR RH20 APo w e r w i n d o w s , o u t s i d e r e a r v i e w
mirrors
14AM215 ASmart access system with push-button
start
15RH-IG7. 5 A
Seat belts, intuitive parking assist,
automatic transmission, seat heater
and ventilator
16FR S/HTR RH15 ASeat heaters and ventilators
17ECU-IG RH10 A
Power seats, smart access system with
push-button start, AWD system, out-
side rear view mirrors, VDIM, VSC,
air conditioning system, pre-collision
seat belt, electric tilt and telescopic
steering, power windows, navigation
system
■After a fuse is replaced
●If the lights do not turn on even after the fuse has been replaced, a bulb may
need replacement. (
→P. 3 4 2 )
●If the replaced fuse blows again, have the vehicle inspected by your Lexus
dealer.
■If there is an overload in the circuits
The fuses are designed to blow before the entire wiring harness is damaged.

5
When trouble arises
351
5-1. Essential information
08_IS350/250_U_(L/O_0708)
■Emergency towing procedureRelease the parking brake.
Shift the shift lever to N.
Put the “ENGINE START STOP” switch in ACCESSORY mode (engine
off) or IGNITION ON mode (engine running).
CAUTION
■Caution while towing
●Use extreme caution when towing the vehicle.
Avoid sudden starts or erratic driving maneuvers which place excessive stress on
the emergency towing eyelets and the cables or chains.
●If the engine is not running, the power assist for the brakes and steering will not
function, making steering and braking more difficult.
NOTICE
■To prevent causing serious damage to the transmission
(vehicles with an automatic transmission)
Never tow this vehicle from the front with the rear wheels on the ground.
This may cause serious damage to the transmission.
■When towing a vehicle without using a towing dolly
(vehicles with a manual transmission)
The “ENGINE START STOP” switch must not be OFF.
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STEP3