2008 Lexus IS250 Vsc

173
2-4. Using other driving systems
2
When driving
08_IS350/250_U_(L/O_0708)
■Automatic reactivation of TRAC and VSC
Turning the “ENGINE START STOP” switch OFF after turning off the TRAC and
VSC systems will automatically re-enable them.
■Automatic TRAC reactivation
If only the TRAC system is turned off, the TRAC system will turn on when vehicle
speed increases.
■Automatic TRAC and VSC reactivation
If the TRAC and VSC systems are turned off, the systems will not turn on even when
vehicle speed increases.
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC and hill-start
assist control systems
●A sound may be heard from the engine compartment when the engine is
started or just after the vehicle begins to move. This sound does not indicate that
a malfunction has occurred in any of these systems.
●Any of the following conditions may occur when the above systems are operat-
ing. None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly after the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.

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.

332
4-3. Do-it-yourself maintenance
08_IS350/250_U_(L/O_0708)
FuseAmpereCircuit
10E/G-B60 AFR CTRL-B, ETCS, ALT-S, steering
lock system, exhaust system
11DIESEL GLW80 A
12ABS150 AVSC, VDIM
13RH J/B-B30 APower door lock system, smart access
system with push-button start
14MAIN30 AHeadlight low beams
15STARTER30 ASmart access system with push-button
start
16LH J/B-B30 APower door lock system, SECURITY
17P/ I - B60 A
Multiport fuel injection system/
sequential multiport fuel injection sys-
tem
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 AVSC
23DEFOG50 ARear window defogger
24FA N 240 AElectric cooling fans
25FA N 140 AElectric cooling fans
26HEATER50 AAir conditioning system

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.

358
5-1. Essential information
08_IS350/250_U_(L/O_0708)
Event data recorder
In a crash or a near car crash eventThe SRS airbag sensor assembly contains the EDR. In a crash or a near
car crash event, this device may record some or all of the following infor-
mation:
● Engine speed
● Whether the brake pedal was applied or not
● Ve h i c l e s p e e d
● To what extent the accelerator pedal was depressed
● Position of the transmission shift lever
● Whether the driver and front passenger wore seat belts or not
● Driver's seat position
● SRS airbag deployment data
● SRS airbag system diagnostic data
If your vehicles is equipped with a vehicle stability control (VSC) system
The VSC Electronic Control Unit (ECU) may contain another EDR. In
case the VSC or Brake Assist system is activated, or the lateral accelera-
tion is beyond a certain valve, this device may record some or all of the
following information:
●Behavior of the vehicle
● Steering wheel angle
Your vehicle has computers that monitor and control certain aspects of
your vehicle. These computers assist in driving and maintaining optimal
vehicle performance.
Besides storing data useful for troubleshooting, there is an event data
recorder (EDR) that records data in a crash or a near car crash event.

372
5-2. Steps to take in an emergency
08_IS350/250_U_(L/O_0708)
Have the vehicle inspected by your Lexus dealer immediately.Failing to investigate the cause of the following warning may lead to the
system operating abnormally and possibly cause an accident. Have the
vehicle inspected by your Lexus dealer immediately.
Wa r n i n g m e s s a g eDetails
Indicates a malfunction in the TRAC, VSC or hill-
start assist control systems.

5
When trouble arises
389
5-2. Steps to take in an emergency
08_IS350/250_U_(L/O_0708)
CAUTION
■When using the compact 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 compact 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 compact spare tire attached
The vehicle speed may not be correctly detected, and the following systems may
not operate correctly:
●ABS & Brake assist
●VSC
●TRAC
●Navigation system (if equipped)
Also, not only can the following system not be utilized fully, it may actually negatively
effect the drive-train components:
●AWD system

402
5-2. Steps to take in an emergency
08_IS350/250_U_(L/O_0708)
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 put the selector
lever in P (vehicles with an automatic transmission) or N (vehi-
cles 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 (automatic) or 1 or R
position (manual) 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 7 2 )
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