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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.
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394
4-3. Do-it-yourself maintenance
IS350/250_U
Radiator and condenserCheck the radiator and condenser and clear any foreign objects.
If either of the above parts are extremely dirty or you are not sure of their
condition, have your vehicle checked by your Lexus dealer.
Brake fluid■ Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
lines on the tank.
Make sure to check the fluid type and prepare the necessary items.
■ Adding fluid
CAUTION
■When the engine is hot
Do not touch the radiator or condenser, as they may be hot and you may be burned.
Fluid typeFMVSS No.116 DOT 3 or SAE J1703 brake fluid
ItemsClean funnel
■Brake fluid can absorb moisture from the air
Excess moisture in the fluid can cause a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
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423
4-3. Do-it-yourself maintenance
4
Maintenance and care
IS350/250_U
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may have blown.
If this happens, check and replace the fuses as necessary.
Turn the “ENGINE START STOP” switch OFF.
Engine compartment (type B fuse box): Remove the engine
compartment cover. ( →P. 388)
Open the fuse box cover.
Engine compartment (type A fuse box)
Push the tabs in and lift the lid
off.
Engine compartment (type B fuse box) Push the tabs in and lift the lid
off.STEP1
STEP2
STEP3
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426
4-3. Do-it-yourself maintenance
IS350/250_U
Removing the front controller (engine compartment: type B fuse box)
Lift the lid off while pushing the
tabs on either side.
Ty p e D Normal fuse
Blown fuse
Contact your Lexus dealer.
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428
4-3. Do-it-yourself maintenance
IS350/250_U
10E/G-B60 AFR CTRL-B, ETCS, ALT-S, A/F, STR
LO C K
11DIESEL GLW80 A
12ABS150 AVDIM
13RH J/B-B30 AFR DOOR RH, RR DOOR RH, AM2
14MAIN30 AH-LP R LWR, H-LP L LWR
15STARTER30 ASmart access system with push-button
start
16LH J/B-B30 AFR DOOR LH, RR DOOR LH,
SECURITY
17P/ I - B60 AEFI, F/PMP, INJ
18EPS80 APo w e r s t e e r i n g
19ALT150 A
LH J/B-AM, E/G-AM, GLW PLG2,
HEATER, FAN1, FAN2, DEFOG,
ABS2, RH J/B-AM, GLW PLG1,
LH J/B-B, RH J/B-B
20GLW PLG150 APTC heater
21RH J/B-AM80 A
OBD, STOP SW, TI&TE, FR P/SEAT
RH, RAD NO.3, ECU-IG RH,
RH-IG, FR S/HTR RH, ACC, CIG,
PWR OUTLET
22ABS230 AVDIM
23DEFOG50 ARear window defogger
24FA N 240 AElectric cooling fans
25FA N 140 AAir conditioning system
26HEATER50 AAir conditioning system
27GLW PLG250 APTC heater
FuseAmpereCircuit
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5-2. Steps to take in an emergency
IS350/250_U
Stop the vehicle immediately.
The following warning indicates the possibility of damage to the vehicle
that may lead to an accident. Immediately stop the vehicle in a safe place
and contact your Lexus dealer.
Have the vehicle inspected by your Lexus dealer immediately. Failing to investigate the cause of the following warnings may lead to the
system operating abnormally and possibly cause an accident. Have the
vehicle inspected by your Lexus dealer immediately.
Warning lightWarning light/Details
Charging system warning light Indicates a malfunction in the vehicle’s charging system.
Warning lightWarning light/Details
(U.S.A.)
(Canada)
Malfunction indicator lampIndicates a malfunction in:
• The electronic engine control system;
• The electronic throttle control system; or
• The electronic automatic transmission control system.
SRS warning lightIndicates a malfunction in:
• The SRS airbag system; or
• The seat belt pretensioner system.
(U.S.A.)
(Canada)
ABS warning lightIndicates a malfunction in:
•The ABS;
• The brake assist system.
Electric power steering system warning light
Indicates a malfunction in the EPS (Electric Power Steering)
system.
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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
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IS350/250_U
Abbreviation list
Abbreviation/Acronym list
ABBREVIATIONSMEANING
ABSAnti-lock Brake System
AI-SHIFTArtificial Intelligence Shift
ALRAutomatic Locking Retractor
AW DAll Wheel Drive
CRSChild Restraint System
DISPDisplay
ECTElectronic Controlled Transmission
ECUElectronic Control Unit
EDREvent data recorder
ELREmergency Locking Retractor
EPSElectric Power Steering
ETCSElectronic Throttle Control System
GAWRGross Axle Weight Rating
I/MEmission inspection and maintenance
LATCHLower Anchors and Tethers for Children
LEDLight Emitting Diode
MMTMethylcyclopentadienyl Manganese Tricarbonyl
M + SMud and Snow
MTBEMethyl Tertiary Butyl Ether
OBDOn Board Diagnostics
SRSSupplemental Restraint System
TINTire Identification Number
TPMSTire Pressure Warning System
TRACTr a c t i o n C o n t r o l
VDIMVehicle Dynamics Integrated Management