ECU Lexus IS250 2008 Owner's Guide

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4-3. Do-it-yourself maintenance
4
Maintenance and care
08_IS350/250_U_(L/O_0708)
FuseAmpereCircuit
27GLW PLG250 APTC heater
28E/G-AM60 AHeadlight cleaners, front fog lights,
parking lights, air conditioning system
29LH J/B-AM80 A
S/ROOF, FR P/SEAT LH, TV NO.1,
A/C, FUEL/OPEN, PSB, FR WIP,
H-LP LVL, LH-IG, ECU-IG LH,
PA N E L , TA I L , M I R H T R ,
FR S/HTR LH

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4-3. Do-it-yourself maintenance
08_IS350/250_U_(L/O_0708)■
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 APre-collision seat belt
8S/ROOF25 AElectric moon roof
9TA I L10 ATail lights, license plate lights, parking
lights
10PA N E L7. 5 ASwitch illumination, air conditioning
system, display
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
13FR S/HTR LH15 ASeat heaters and ventilators

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4-3. Do-it-yourself maintenance
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Maintenance and care
08_IS350/250_U_(L/O_0708)
FuseAmpereCircuit
14RR DOOR LH20 APo w e r w i n d o w s
15FR DOOR LH20 APo w e r w i n d o w s
16SECURITY7. 5 ASmart access system with push-button
start
17H-LP LVL7. 5 AAFS
18LH-IG10 A
Charging system, headlight cleaner,
rear window defogger, electric cool-
ing fans, emergency flashers, turn sig-
nal lights, back-up lights, stop lights,
mirror heaters, sun shade, seat belts,
Intuitive parking assist, cruise control,
air conditioning system, PTC heater
19FR WIP30 AWindshield wipers

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4-3. Do-it-yourself maintenance
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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.

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4-3. Do-it-yourself maintenance
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Maintenance and care
08_IS350/250_U_(L/O_0708)
■When replacing the front left headlight and parking light bulbs
■Condensation build-up on the inside of the lens
Contact your Lexus dealer for more information in the following situations. Tempo-
rary condensation build-up on the inside of the headlight lens does not indicate a
malfunction.
●Large drops of water are built up on the inside of the lens.
●Water has built up inside the headlight.
■Discharge headlights (if equipped)
If voltage to the discharge bulbs is insufficient, the bulbs may not come on, or may
go out temporarily. The discharge bulbs will come on when normal power is
restored. Remove the securing bolt and move the
washer fluid filler opening to allow easy
access to the light bulbs.
After replacing the bulbs, make sure to
secure the washer fluid filler opening with the
bolt.

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4-3. Do-it-yourself maintenance
08_IS350/250_U_(L/O_0708)
CAUTION
■Replacing light bulbs
●Turn off the headlights. Do not attempt to replace the bulb immediately after turn-
ing off the headlights.
The bulbs become very hot and may cause burns.
●Do not touch the glass portion of the light bulb with bare hands. Hold the bulb by
the plastic or metal portion.
If the bulb is scratched or dropped it may blow out or crack.
●Fully install light bulbs and any parts used to secure them. Failing to do so may
result in heat damage, fire, or water entering the headlight unit. This may damage
the headlights or cause condensation to build up on the lens.
●Do not attempt to take apart or repair the low beam headlight bulbs, connectors,
power supply circuits, or related components.
Doing so could result in electric shock and serious injury or death.
■Discharge headlights (if equipped)
●Contact your Lexus dealer before replacing discharge headlights (including light
bulbs).
●Do not touch the high-intensity discharge headlight’s high voltage socket when
the headlights are turned on.
An extremely high voltage of 20000 V will be discharged and could result in
serious injury or death by electric shock.
■To prevent damage or fire
Make sure bulbs are fully seated and locked.

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5-1. Essential information
If your vehicle needs to be towed
Before towingThe following may indicate a problem with your transmission. Contact
your Lexus dealer before towing.
● The engine is running, but the vehicle will not move.
● The vehicle makes an abnormal sound.
Emergency towing
If a tow truck is not available, in an emergency your vehicle may be tem-
porarily towed using a cable or chain secured to the emergency towing
eyelet(s). This should only attempted on hard, surfaced roads for short
distances at low speeds.
A driver must be in the vehicle to steer and operate the brakes. The vehi-
cle’s wheels, drive train, axles, steer ing and brakes must be in good condi-
tion.
Towing eyelets
If towing is necessary, we recommend having your vehicle towed by your
Lexus dealer or a commercial towing se rvice, using a lift-type truck or a flat
bed truck.
Use a safety chain system for all towing, and abide by all state/provincial
and local laws.
If towing from the rear, the vehicle’s front wheels and axles must be in good
condition. (
→P. 3 5 4 )
If they are damaged, use a to wing dolly or flat bed truck.

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Installing towing eyeletsRemove the eyelet cover using a
flat head screwdriver.
To protect the bodywork, place a
rag between the screwdriver and
the vehicle body, as shown in the
illustration.
Insert the towing eyelet into the
hole and tighten partially by hand.
Tighten down the towing eyelet
securely using a wheel nut wrench.
STEP1
STEP2
STEP3
■Location of the emergency towing eyelet
→P. 3 8 2

5
When trouble arises
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5-1. Essential information
08_IS350/250_U_(L/O_0708)
Towing with a sling-type truck
CAUTION
■Installing towing eyelets to the vehicle
Make sure that towing eyelets are installed securely.
If not securely installed, towing eyelets may come loose during towing. This may
lead to accidents that cause serious injury or even death.
NOTICE
■To prevent body damage
Do not tow with a sling type truck, either from the front or rear.

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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.