
190
2-4. Using other driving systems
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. Always drive carefully. Reckless driving may cause
an accident. Exercise particular care when the indicator light flashes.
■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, VSC and TRAC systems will not function correctly if different tires are fit-
ted 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.

432
4-3. Do-it-yourself maintenance
IS350/250_U■
Driver’s side instrument panel
FuseAmpereCircuit
1FR P/SEAT LH30 APo w e r s e a t
2A/C7. 5 AAir conditioning system
3MIR HTR15 AOutside rear view mirror defoggers
4TV NO.110 ADisplay
5FUEL OPEN10 AFuel filler door opener
6TV NO.27. 5 A
7PSB30 A
8S/ROOF25 AMoon roof
9TA I L10 ATail lights, license plate lights, parking
lights
10PA N E L7. 5 ASwitch illumination, air conditioning
system, display, audio
11RR FOG7. 5 A
12ECU-IG LH10 A
Cruise control, air conditioning sys-
tem, power steering, rain sensor, anti-
glare inside rear view mirror, shift lock
system, moon roof, tire inflation pres-
sure warning system, VSC
13FR S/HTR LH15 ASeat heaters and ventilators

5
When trouble arises
463
5-2. Steps to take in an emergency
IS350/250_U
Follow the correction procedures.After taking the specified steps to co rrect the suspected problem, check
that the warning light turns off.
Warning lightWarning light/Details
Slip indicator
Indicates a malfunction in:
• The VSC system;
• The TRAC system; or
• The hill-start assist control system
Warning lightWarning light/DetailsCorrection procedure
Open door warning light
(warning buzzer)
*1
Indicates that a door or the
trunk is not fully closed.
Check that all doors and the
trunk are closed.
Low fuel level warning light
Remaining fuel
(Approximately 2.9 gal. [11 L,
2.4 Imp. gal.] or less)
Refuel the vehicle.
(On the instru-ment cluster)
Driver’s seat belt reminder
light (warning buzzer)
*2
Warns the driver to fasten
his/her seat belt.Fasten the seat belt.
(On the center
panel)
Front passenger’s seat belt
reminder light
(warning buzzer)
*2
Warns the front passenger to
fasten his/her seat belt.
Fasten the seat belt.

5
When trouble arises
487
5-2. Steps to take in an emergency
IS350/250_U
CAUTION
●Use a jack stand if it is necessary to get under the vehicle.
Take particular care when lowering the vehicle to ensure that no one working on or
near the vehicle may be injured.
■Replacing a flat tire
Observe the following precautions to reduce the risk of death or serious injury.
●Never use oil or grease on the wheel bolts or wheel nuts.
Oil and grease may cause the wheel nuts to be excessively tightened, leading to
bolt or disc wheel damage. In addition, the oil or grease can cause the wheel nuts
to loosen and the wheel may fall off, causing a serious accident. Remove any oil or
grease from the wheel bolts or wheel nuts.
●Have the wheel nuts tightened with a torque wrench to 76 ft•lbf (103 N•m, 10.5
kgf•m) as soon as possible after changing wheels.
Failure to follow these precautions could cause the nuts to loosen and the wheels
may fall off, which could lead to an accident causing death or serious injury.
■When using the spare tire
●Remember that your compact spare tire is specifically designed for use with your
vehicle. Do not use your compact spare tire on another vehicle.
●Do not use two compact spare tires simultaneously.
●Replace the compact spare tire with a standard tire as soon as possible.
●Avoid sudden acceleration, deceleration and braking, as well as sharp cornering.
■Speed limit when using the 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. Failing to observe
this precaution may lead to an accident causing death or serious injury.
■When the spare tire is attached
The vehicle speed may not be correctly detected, and the following systems may
not operate correctly:
●ABS & brake assist
●VSC
●TRAC

504
5-2. Steps to take in an emergency
IS350/250_U
If the vehicle becomes stuck
CAUTION
■When attempting to free a stuck vehicle
If you choose to rock the vehicle back and forth to free it, make sure the surround-
ing area is clear, to avoid striking other vehicles, objects or persons. The vehicle
may also lunge forward or lunge back suddenly as it becomes free. Use extreme
caution.
■When shifting the shift lever
With automatic transmission vehicles, be careful not to shift the shift lever with the
accelerator pedal depressed.
This may lead to unexpected rapid acceleration of the vehicle that may cause an
accident and result in death or serious injury.
Carry out the following procedures if the tires spin or the vehicle becomes
stuck in mud, dirt, or snow.
Stop the engine. Set the parking brake and shift the shift lever
to P (vehicles with an automatic transmission) or N (vehicles
with a manual transmission).
Remove the mud, snow, or sand from around the stuck tire.
Place wood, stones or some other material to help provide
traction under the tires.
Restart the engine.
Shift the shift lever to the D or R position (vehicles with an auto-
matic transmission) or 1 or R position (vehicles with a manual
transmission), release the parking brake and carefully apply
the accelerator to free the vehicle.
Turn off TRAC and VSC if these functions are hampering your
attempts to free the vehicle. (→ P. 1 8 7 )
STEP1
STEP2
STEP3
STEP4
STEP5

563
Abbreviation list
IS350/250_U
VINVehicle Identification Number
VSCVehicle Stability Control
ABBREVIATIONSMEANING

572
Alphabetical index
IS350/250_U
TachometerTacho indicator...................................... 151
Tachometer ............................................. 151
Tail lights
Switch ....................................................... 165
Talk switch ...............................................289
Telephone switch ................................. 288
Theft deterrent system
Alarm .......................................................... 87
Engine immobilizer system ............. 85
Theft prevention labels ..........................90
Tire inflation pressure .......................... 412
Tire information Glossary................................................. 533
Size ...........................................................530
Tire identification number .............530
Uniform tire quality grading ...........531
Tires
Chains ...................................................... 195
Checking .............................................. 400
If you have a flat tire........................... 481
Inflation pressure.................................. 412
Inflation pressure sensor................ 402
Information............................................528
Replacing................................................ 481
Rotating tires ....................................... 400
Size ............................................................ 519
Snow tires ............................................... 195
Tools ............................................................ 481
Total load capacity ................................ 194 Towing
Dinghy towing ......................... 200, 201
Emergency towing ............................. 451
Trailer towing ........................................ 199
TRAC ......................................................... 185
Traction control...................................... 185
Transmission shift switches.................142
Trip meter ................................................... 151
Trunk Extending trunk space.....................344
Opener ...................................................... 47
Trunk light
Trunk light ................................................ 48
Wattage ................................................. 524
Turn signal lights Replacing light bulbs ....................... 439
Switch........................................................ 147
Wattage ................................................. 524
USB port ...................................................... 250
Vanity lights Vanity lights........................................... 327
Wattage ................................................. 524
Vanity mirrors ........................................ 327
VDIM.......................................................... 185
Vehicle dynamics integrated management ........................................ 185
Vehicle identification number .........509
Vehicle stability control ...................... 185
Ventilators ...............................................338
Voice command switch .....................288
VSC ............................................................ 185T
U
V