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2-4. Using other driving systems
IS250C/350C_U
■EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be
heard. This does not indicate a malfunction.
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from over-
heating when there is frequent steering input over an extended period of time. The
steering wheel may feel heavy as a result. Should this occur, refrain from excessive
steering input or stop the vehicle and turn the engine off. The EPS system should
return to normal within 10 minutes.
■If the slip indicator comes on
It may indicate a malfunction in the VSC or TRAC function.
Contact your Lexus dealer.
CAUTION
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road).
●The vehicle hydroplanes while driving at high speed on the wet or slick road.
■Stopping distance when the ABS is operating may exceed that of normal condi-
tions
The ABS is not designed to shorten the vehicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you, especially in the following situa-
tions.
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or roads with uneven roads
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2-4. Using other driving systems
2
When driving
IS250C/350C_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.
■When the VSC is activated
The slip indicator light flashes. Always drive carefully. Reckless driving may cause
an accident, resulting in death or serious injury. 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 help enhance 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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2-4. Using other driving systems
2
When driving
IS250C/350C_U
CAUTION
■Limitations of the pre-collision system
Do not rely on the pre-collision system. Always drive safely, taking care to observe
your surroundings and checking for any obstacles or other road hazards.
Failure to do so may cause an accident resulting in death or serious injury.
■Cautions regarding the assist contents of the system
By means of alarms and brake control, the pre-collision system is intended to assist
the driver in avoiding collisions through the process of LOOK-JUDGE-ACT. There
are limits to the degree of assistance the system can provide, so please keep in mind
the following important points.
●Assisting the driver in watching the road
The pre-collision system is only able to detect obstacles directly in front of the
vehicle, and only within a limited range. It is not a mechanism that allows careless
or inattentive driving, and it is not a system that can assist the driver in low-visibil-
ity conditions. It is still necessary for the driver to pay close attention to the vehi-
cle’s surroundings.
●Assisting the driver in making correct judgment
When attempting to estimate the possibility of a collision, the only data available
to the pre-collision system is that from obstacles it has detected directly in front of
the vehicle. Therefore, it is absolutely necessary for the driver to remain vigilant
and to determine whether or not there is a possibility of collision in any given situ-
ation.
●Assisting the driver in taking action
The pre-collision system’s braking assist feature is designed to help reduce the
severity of a collision, and so only acts when the system has judged that a collision
is unavoidable. This system by itself is not capable of automatically avoiding a col-
lision or bringing the vehicle to a stop safely. For this reason, when encountering a
dangerous situation the driver must take direct and immediate action in order to
ensure the safety of all involved.
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4-3. Do-it-yourself maintenance
4
Maintenance and care
IS250C/350C_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 cause serious inju-
ries, such as burns.
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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4-3. Do-it-yourself maintenance
4
Maintenance and care
IS250C/350C_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. 4 1 8 )
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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4-3. Do-it-yourself maintenance
IS250C/350C_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 C Normal fuse
Blown fuse
Contact your Lexus dealer.
Ty p e DNormal fuse
Blown fuse
Contact your Lexus dealer.
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4-3. Do-it-yourself maintenance
IS250C/350C_U
9E/G-B60 AFR CTRL-B, ETCS, ALT-S, A/F, TEL,
STR LOCK
10ABS150 AVDIM
11RH J/B-B30 AFR DOOR RH, AM2
12MAIN30 AH-LP R LWR, H-LP L LWR
13STARTER30 ASmart access system with push-button
start
14LH J/B-B30 AFR DOOR LH, SECURITY
15P/ I - B60 AINJ, F/PMP, EFI
16EPS80 APo w e r s t e e r i n g
17ALT150 A
LH J/B-AM, E/G-AM, GLW PLG2,
HEATER, FAN1, FAN2, ABS2, RH
J/B-AM, GLW PLG1, RR R/B-AM
18RR R/B-AM80 A
DEFOG, PSB, ROOF RH, ROOF
LH, LGG RH, LGG LH, LGG LCK
RH, LGG LCK LH, P-TRAY MAIN,
P-T R AY S I D E
19GLW PLG150 APTC heater
20RH 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, DOOR DL
21ABS230 AVDIM
22FA N 240 AElectric cooling fans
23FA N 140 AElectric cooling fans
24HEATER50 AAir conditioning system
25GLW PLG250 APTC heater
FuseAmpereCircuit
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4-3. Do-it-yourself maintenance
4
Maintenance and care
IS250C/350C_UReplace the light bulb, and install
the bulb base.
Align the 3 tabs on the light bulb
with the mounting, and insert.
Turn and secure the bulb base.
Shake the bulb base gently to
check that it is not loose, turn the
headlight high beams and daytime
running lights on once and visually
confirm that no light is leaking
through the mounting.
When installing the cover install by conducting with the
directions reversed.
STEP4
STEP5
STEP6STEP1