2010 Lexus IS250 air conditioning

440
4-3. Do-it-yourself maintenance
IS350/250_U
Fuse layout and amperage ratings■ Engine compartment (type A fuse box)
FuseAmpereCircuit
1PWR HTR25 A
2TURN-HAZ15 AEmergency flashers, turn signals
3IG2 MAIN20 AIG2, IGN, GAUGE
4RAD NO.230 AAudio
5D/C CUT20 ADOME, MPX-B
6RAD NO.130 AAudio
7MPX-B10 A
Headlights, front fog lights, parking
lights, license plate lights, windshield
washer, horn, power door lock system,
power windows, power seats, electric
tilt and telescopic steering column,
meter, smart access system with push-
button start, outside rear view mirrors,
air conditioning system, multiplex
communication system
8DOME10 AInterior lights, meter
9CDS10 AElectric cooling fans

441
4-3. Do-it-yourself maintenance
4
Maintenance and care
IS350/250_U
FuseAmpereCircuit
10E/G-B60 AFR CTRL-B, ETCS, ALT-S, steering
lock system, exhaust system
11DIESEL GLW80 A
12ABS150 AVDIM
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 APower steering
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 AElectric cooling fans
26HEATER50 AAir conditioning system

442
4-3. Do-it-yourself maintenance
IS350/250_U
FuseAmpereCircuit
27GLW PLG250 APTC heater
28E/G-AM60 A
Headlight cleaners, front fog lights,
parking lights, air conditioning system
DEICER
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

443
4-3. Do-it-yourself maintenance
4
Maintenance and care
IS350/250_U■
Engine compartment (type B fuse box)
FuseAmpereCircuit
1SPARE30 ASpare fuse
2SPARE25 ASpare fuse
3SPARE10 ASpare fuse
4FR CTRL-B25 AHeadlight high beams, horn
5A/F15 AExhaust system
6ETCS10 A
Multiport fuel injection system/
sequential multiport fuel injection sys-
tem
7ALT-S7. 5 ACharging system
8TEL10 ALexus Enform
9STR LOCK25 ASteering lock
10H-LP CLN30 AHeadlight cleaner
11A/C COMP7. 5 AAir conditioning system
12DEICER25 AWindshield wiper de-icer
13FR CTRL-AM30 AFront fog lights, parking lights, wind-
shield washer

445
4-3. Do-it-yourself maintenance
4
Maintenance and care
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 APre-collision seat belt
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
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

446
4-3. Do-it-yourself maintenance
IS350/250_U
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

5
When trouble arises
467
5-1. Essential information
IS350/250_U
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■Visible symptoms
●Fluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temperature gauge needle continually points
higher than normal
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the engine
■ Operational symptoms
●Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, sp ongy feeling, pedal almost touches
the floor

512
5-2. Steps to take in an emergency
IS350/250_U
If your vehicle overheats
If your engine overheats:
Stop the vehicle in a safe place and turn off the automatic air
conditioning system.
Check to see if steam is coming out from under the hood.
If you see steam: Stop the engine. Carefully lift the hood after the steam sub-
sides and then restart the engine.
If you do not see steam: Leave the engine running and carefully lift the hood.
Remove the engine compartment cover. ( →P. 4 0 2 )
Check to see if the cooling fans are operating.
If the fans are operating: Wait until the temperature of the engine (shown on the
instrument cluster) begins to fall and then stop the engine.
If the fans are not operating: Stop the engine immediately and call your local Lexus
dealer.
After the engine has cooled
down sufficiently, check the
engine coolant level and inspect
the radiator core (radiator) for
any leaks.STEP1
STEP2
STEP3
STEP4
STEP5