2008 Lexus GS450h light

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4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
■How to initialize the tire pressure warning system
Park the vehicle in safe place and turn the “POWER” switch to
OFF.
While the vehicle is moving, initialization is not performed.
Adjust the tire inflation pressure to the specified cold tire inflation
pressure level. ( P. 5 5 1 )
Make sure to adjust the tire pressure to the specified cold tire inflation
pressure level. The tire pressure warning system will operate based on
this pressure level.
Turn the “POWER” switch to ON mode.
Push and hold the tire pressure
warning reset switch until the tire
pressure warning light blinks
slowly three times and the mes-
sage “PRESSURE INITIAL”
appears on the multi-information
display.
Wait for a few minutes with the ON mode, and then turn
“POWER” switch to the OFF.
STEP1
STEP2
STEP3
STEP4
STEP5

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4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
Registering and selecting ID codes■ Registering ID codes
2 sets of tire pressure warning va lve and transmitter ID codes can be
registered. Once a second set of ti res is registered at “2nd”, you can
switch between tire set settings simply by pressing the tire pressure
warning select switch.
There are 2 settings:
“MAIN” position: The ID code of the tire pressure warning valve and
transmitter on the tires originally inst alled on the vehicle is registered.
“2nd” position: The ID code is not registered. When you replace a new
set of tires, purchase tire pressu re warning valves and transmitters
from your Lexus dealer and have the new ID code registered by your
Lexus dealer.
■ Selecting ID codes
When replacing tires, make sure to select the ID code set that matches
the new tire set. If the tire pressure warning select switch is set to the
wrong tire setting, the tire pressu re warning system will not operate
properly. After driving for about 20 minutes, the tire pressure warning
light comes on after blinking for 1 minute to indicate a system malfunc-
tion.
“MAIN”
“2nd”

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4-3. Do-it-yourself maintenance
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Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
■When to replace your vehicle’s tires
Tires should be replaced if:
●You have tire damage such as cuts, splits, cracks deep enough to expose the
fabric or bulges indicating internal damage
●A tire goes flat repeatedly or cannot be properly repaired due to the size or
location of a cut or other damage
If you are not sure, consult with your Lexus dealer.
■Replacing tires and wheels
If the ID code of the tire pressure warn ing valve and transmitter is not registered,
the tire pressure warning system will not work properly. After driving for about 20
minutes, the tire pressure warning light comes on after blinking for 1 minute to indi-
cate a system malfunction.
■Tire life
Any tire over 6 years old must be checked by a qualified technician even if they
have seldom or never been used or damage is not obvious.
■If the tread wears down below 0.16 in. (4 mm) on snow tires
The effectiveness of snow tires is lost.
■Low profile tires (245/40R18, P245/40R18 and 245/40ZR18 tires)
Generally, low profile tires will wear more rapidly and tire grip performance will be
reduced on snowy and/or icy roads when co mpared to standard tires. Be sure to
use snow tires or snow chains on snowy and/or icy roads and drive carefully at a
speed appropriate for road and weather conditions.
■Initializing the tire pressure warning system
Initialize the tires with the tire inflatio n pressure adjusted to the specified level.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
■Initializing the tire pressure warning system
Initialize the tires with the tire inflation pressure adjusted to the specified level.
■If you push the tire pressure warning reset switch accidentally
If initialization is performed, adjust the ti re inflation pressure to the specified level
and initialize the system again.
■When the initialization of the tire pressure warning system has failed
Initialization can be completed in a few minutes. However, in the following cases,
the settings have not been recorded and the system will not operate properly. If
repeated attempts to record tire inflation pressure settings are unsuccessful, have
the vehicle inspected by your Lexus dealer.
●When operating the tire pressure warnin g reset switch, the tire pressure warn-
ing light does not flash 3 times and the setting message does not appear on the
multi-information display.
●After carrying out the initia lization procedure, the tire pressure warning light
blinks for 1 minute then stays on after driving for 20 minutes.
■Routine tire inflation pressure checks
The tire pressure warning system does not replace routine tire inflation pressure
checks. Make sure to check tire inflation pressure as part of your routine of daily
vehicle checks.

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4-3. Do-it-yourself maintenance
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Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
For vehicles sold in Canada
NOTE:
Operation is subject to the following two conditions: (1) this device may not cause
interference, and (2) this device must a ccept any interference, including interfer-
ence that may cause undesired operation of the device.
CAUTION
■When inspecting or replacing tires
Observe the following precautions to prevent accidents. Failure to do so may cause
damage to parts of the drive train, as we ll as dangerous handling characteristics,
which may lead to fatal or injury accidents.
●Do not mix tires of different makes, models, tread patterns or treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix radial, bias-belted, or bias-ply tires.
●Do not mix summer, all season and winter tires.
●Do not use tires that have been used on another vehicle. 
Do not use tires if you do not know how they were used previously.
■When initializing the tire pressure warning system
Do not push the tire pressure warning reset switch without first adjusting the tire
inflation pressure to the specified level. Otherwise, the tire pressure warning light
may not come on even if the tire inflation pressure is low, or it may come on when
the tire inflation pressure is actually normal.

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4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
Fuse layout and amperage ratings■ Engine compartment
FuseAmpereCircuit
1FR CTRL-B25H-LP HI, HORN
2RELIEF VLV10Fuel system
3ETCS10
Multiport fuel injection system/
sequential multiport fuel injection
system
4H-LP CLN30Headlight cleaner
5STB-AM30Active stabilizer suspension system
6DEICER25
7FR CTRL-AM30FR TAIL, FR FOG, WASH

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4-3. Do-it-yourself maintenance
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Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
FuseAmpereCircuit
8IG210
Multiport fuel injection system/
sequential multiport fuel injection
system, noise filter
9EFI No.210Fuel system, exhaust system
10H-LP R LWR15Headlight low beam (right)
11H-LP L LWR15Headlight low beam (left)
12D/C CUT30DOME, MPX-B
13IGCT No.37. 5Hybrid battery (traction battery)
14IGCT No.27. 5Hybrid system
15MPX-B7. 5
Power windows, door control system,
power seat, electronically controlled
brake system, combination switch,
electric tilt and telescopic steering,
gauges and meters
16DOME7. 5Interior lights, foot lights, vanity light,
gauges and meters
17ABS MAIN110Electronically controlled brake sys-
tem
18ABS MOTOR30ABS
19ABS MAIN210Electronically controlled brake sys-
tem
20F/ P M P25Fuel system
21EFI25
EFI2, multiport fuel injection system/
sequential multiport fuel injection
system
22INJ20
Multiport fuel injection system/
sequential multiport fuel injection
system

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4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
FuseAmpereCircuit
23A/F15Fuel system
24INV W/P10Hybrid system
25IGCT No.120Hybrid system, IGCT No.2, 
IGCT No.3
26FR FOG15Fog light
27FR TAIL10Tail light, rear side marker light
28WA S H20Windshield wipers and washer
29HORN10Horn
30H-LP UPR20Headlight high beam
31DC/DC140Charging system
32RAD FAN60Electric cooling fans
33LH J/B AM80
S/ROOF, FR P/SEAT LH, TV, A/C,
FUEL OPN, FR WIP, H-LP LVL, 
FR S/HTR LH, A/C W/P
34E/G AM60H-LP CLN, FR CTRL-AM, DEICER,
STB AM
35HEATER50Air conditioning system
36DEFOG50Rear window defogger
37ABS230VSC, ABS
38RH J/B-AM80
AM1, OBD, STOP SW, TI & TE, 
FR P/SEAT RH, STR LOCK, 
SECURITY, ECU-IG R, RH-IG, 
F S/HTR RH, CIG, PWR OUTLET, 
AIR SUS