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4-3. Do-it-yourself maintenance
GS_G_U
May 13, 2008 5:14 pm
FuseAmpereCircuit
31FA N 140Electric cooling fans
32HEATER50Air conditioning system
33FA N 240Electric cooling fans
34E/G-AM60H-LP CLN, FR CTRL ALT, A/C 
COMP and STB-AM
35RR J/B80
STOP LP R, STOP LP L, RR-B, 
RR TAIL, RR FOG, RR-IG1, PSB, 
and RR S/SHADE 
     
        
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4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_G_U
May 13, 2008 5:14 pm
FuseAmpereCircuit
24RR J/B80
STOP LP R, STOP LP L, RR-B, 
RR TAIL, RR FOG, RR-IG1, PSB, 
and RR S/SHADE
25GLW PLG150Starting system
26RH J/B-AM80
AM1, OBD, STOP SW, TI&TE,  
PWR OUTLET, FR P/SEAT RH,  
STR LOCK, ECU-IG RH, RH-IG,  
ACC, CIG, SECURITY,  
FR S/HTR RH and AIR SUS
27ABS230ABS
28DEFFOG50Rear window defogger, noise filter
29CDS40CDS
30FA N 140Electric cooling fans
31HEATER50Air conditioning system
32GLW PLG250Starting system
33E/G-AM60H-LP CLN, FR CTRL ALT, A/C 
COMP and STB-AM
34LH J/B-AM80
S/ROOF, P/SEAT, TV, FL S-HTR, 
ECU-IG L, WIP, H-LP LVL, LH-IG, 
FUEL OPN, A/C, PANEL, LH-B and 
TRK OPN
35FA N 260Electric cooling fans 
     
        
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4-3. Do-it-yourself maintenance
GS_G_U
May 13, 2008 5:14 pm
GS350
FuseAmpereCircuit
1FR CTRL-B25H-LP UPR and HORN
2A/F15Exhaust system
3ETCS10Electronic throttle control system
4ALT-S7. 5  Charging system
5H-LP CLN30Headlight cleaner
6A/C COMP7. 5  Air conditioning system
7DEICER25
8FR CTRL-AM30FR TAIL, FR FOG and WASHER
9IG210Ignition system and noise filter
10EFI NO.210Fuel system and exhaust system 
     
        
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4-3. Do-it-yourself maintenance
GS_G_U
May 13, 2008 5:14 pm
■Left side instrument panel
FuseAmpereCircuit
1FR P/SEAT LH30Power seat system
2A/C7. 5Air conditioning system
3TV7. 5Audio system, air conditioning sys-
tem, rear view monitor system
4TRK OPN10Trunk lid opener
5LH-B10Theft deterrent system
6S/ROOF25Moon roof
7PA N E L7. 5
Steering switch illumination, audio 
system, glove box light, automatic 
transmission selector lever illumina-
tion, console box light, adaptive vari-
able suspension switch illumination, 
cigarette lighter illumination, air con-
ditioning system, VSC OFF switch 
illumination, driving pattern selector 
switch, seat heater or heated and 
ventilated seat switches, register ILL 
RH, register ILL LH, fuel filler door 
and trunk lid opener switch illumina-
tion, D-SW module 
     
        
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4-3. Do-it-yourself maintenance
GS_G_U
May 13, 2008 5:14 pm
FuseAmpereCircuit
9IGN10
Multi-port fuel injection system/
sequential multiport fuel injection 
system, SRS airbag system, stop/tail 
lights, steering lock system, electroni-
cally controlled brake system, Lexus 
link system ECU, occupant classifica-
tion system ECU
10ACC7. 5
Multiplex communication system, 
smart access system with push-but-
ton start, rear view monitor system, 
audio system, air conditioning system, 
Lexus link system ECU
11CIG15Cigarette lighter
12PWR OUTLET15Po w e r  o u t l e t
13AIR SUS20Adaptive variable suspension system
14RR DOOR RH20
Rear right door control system 
(power door lock system, door cour-
tesy light, power window)
15FR DOOR RH20
Front right door control system 
(power door lock system, power rear 
view mirror control system, door 
courtesy light, outside rear view mir-
ror heater, power window), multiplex 
communication system 
     
        
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4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_G_U
May 13, 2008 5:14 pm
FuseAmpereCircuit
16AM27. 5Starting system
17RH-IG7. 5
Seat heater switches, front right door 
control system, rear right door con-
trol system, capacitor, combination 
switch, seat belt pretensioners, shift 
lever switch, power window
18FR S/HTR RH15Seat heaters and ventilators
19ECU-IG RH10
Tilt and telescopic steering, combina-
tion switch, multiplex communication 
system, power seat, smart entry & 
start system, air conditioning system, 
audio system, shift lock system 
     
        
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5-1. Essential information
GS_G_U
May 13, 2008 5:14 pm
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 temper ature 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 
     
        
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When trouble arises
533
5-2. Steps to take in an emergency
GS_G_U
May 13, 2008 5:14 pm
If your vehicle overheats
If your engine overheats: 
Stop the vehicle in a safe place and turn off the air conditioning 
system.
Check to see if steam is coming out from under the hood.
If you see steam:  
Stop the engine and car efully lift the hood.
If you do not see steam: Leave the engine running and carefully lift the hood.
Remove the engine compartment cover. ( P.  4 0 8 )
Check to see if the cooling fan is operating.
If the fan is operating:  
Wait until the engine coolant temperature gauge begins to 
fall and then stop the engine.
If the fan is not operating:  
Stop the engine immediately  and call your local Lexus 
dealer.
After the engine has cooled 
down sufficiently, check the 
coolant level and inspect the 
radiator core (radiator) for any 
leaks.STEP1
STEP2
STEP3
STEP4
STEP5