Page 55 of 389
GAUGES, METERS AND SERVICE REMINDER INDICATORS
42
VOLTMETER
SV13021
1Discharge warning light 2Normal range
The voltmeter tells whether the battery is charged or
discharged. Check it while the engine is running ± the
needle should always indicate as shown above.
If the needle reads below or above the normal range while the
engine is running, it indicates that the charging system needs
immediate repair.
However, it is normal for the needle to drop below the normal
range during engine starting.
MOMENTARY FUEL CONSUMPTIONMETER
SV13018
Vehicles sold in U.S.A.
SV13020
Vehicles sold in Canada
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GAUGES, METERS AND SERVICE REMINDER INDICATORS
48
(e) Discharge Warning Light
This light warns that the battery is being discharged.
If it comes on while you are driving, stop the vehicle, turn off the
engine, and check for the cause. Look first at the engine drive
belt.
If it is loose or broken, the generator will not charge the
battery properly.
If the belt is O.K., there is a problem somewhere in the
charging system.
The engine ignition will continue to operate, however, until the
battery is discharged. Turn off the air conditioning, blower,
radio, etc., and drive directly to the nearest Lexus dealer or
repair shop.
NOTICE
Do not continue driving if the engine drive belt is broken or loose.
(f) Low Engine Oil Pressure Warning Light
This light warns that the engine oil pressure is too low.
If it flickers or stays on while you are driving, pull off the road
to a safe place and stop the engine immediately. Call a Lexus
dealer or qualified repair shop for assistance.
The light may occasionally flicker when the engine is idling or
it may come on briefly after a hard stop. There is no cause for
concern if it then goes out when the engine is accelerated
slightly.
The light may come on when the oil level is extremely low. It
is not designed to indicate low oil level, and the oil level must
be checked using the oil level dipstick.
NOTICE
Do not drive the vehicle with the warning light on ± evenfor one block. It may ruin the engine.
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Page 283 of 389

IN CASE OF AN EMERGENCY
2702. If required, remove all the vent plugs from the booster
battery. Lay a cloth over the open vents on the booster battery.
(This
helps reduce the explosion hazard, personal injuries and
burns.)
If the booster battery is an extended maintenance interval
battery, it is not necessary to remove the vent plugs.
3. If the engine in the vehicle with the booster battery is not
running, start it and let it run for about 5 minutes. During jump
starting, run the engine at about 2000 rpm with the accelerator
pedal lightly depressed.
4. Locate positive (+) and negative (±) terminals of each
battery. Conn ect the jumper cables in the exact order (
1
2 3 4) shown in the illustration.
1Connect a positive (red) jumper cable clamp to the
positive (+) terminal of the discharged battery.
2Connect the clamp at the other end of the positive (red)
cable to the positive (+) terminal of the booster battery.
3Connect a negative (black) cable clamp to the negative
(±) terminal of the booster battery.
4Connect the clamp at the other end of the negative (black)
cable to a solid, stationary, unpainted metallic point (such
as shown in the illustration) away from the battery. Do not
connect it to or near any part that moves when the engine
is cranked.
CAUTION
When making the connections, to avoid serious injury,
do not lean over the battery or accidentally let the
jumper cables or clamps touch anything except the
correct battery terminals or the ground.
5. Start your engine in the normal way. After starting, run it at
about 2000 rpm for several minutes with the accelerator pedal
lightly depressed.
6. Carefully disconnect the cables in the exact reverse order:
the negative cable and then the positive cable.
7. Carefully dispose of the battery cover cloths which may
now contain sulfuric acid.
8. If removed, replace all the battery vent plugs.
If the cause of your battery discharging is not apparent (for
example, lights left on), you should have it checked at your
Lexus dealer.
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Page 323 of 389
ENGINE
310± COOLING SYSTEM
Capacity
7.5 L (7.9 qt., 6.6 lmp.qt.)
Coolant typeºToyota Genuine Long Life Coolantº or equivalent
With ethylene±glycol type coolant for a proper corrosion protection o\
f
aluminum components
Do not use alcohol type antifreeze or plain water alone.
NOTE:
ºToyota Genuine Long Life Coolantº is filled in your Lexus vehicle. In order \
to avoid technical problems, we strongly recommend using
ºToyota Genuine Long Life Coolantº or equivalent. Please contact your \
Lexus dealer for further details.
± FUEL
Fuel type
Only UNLEADED
Octane rating91 (Research octane number 96) or higher
± IGNITION SYSTEMSpark plug ± Make DENSO ± Gap
SK16R±P11
1.1 mm (0.043 in.)
± ELECTRICAL SYSTEM
Battery ± Open voltage at 20 C (68F):
Charging rates
12.7 V Fully charged
12.3 V Half charged
11.9 V Discharged
[Voltage that is checked 20 minutes after the key is removed with all the
lights turned off]
5A max.
2003 IS300 from Aug. '02 Prod. (OM53439U)
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SECTION 6 ± 4
343
SERVICE PROCEDURES AND
SPECIFICATIONS
Electrical components
Specifications344
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . . .
Checking battery condition 348
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery recharging precautions 350
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking and replacing the blade type fuses 351
. . . . . . . . . . . . . . . .
Checking the cartridge type fuses 353
. . . . . . . . . . . . . . . . . . . . . . . . . .
Adding washer fluid 354
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
.
Checking the headlight aim 355
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing light bulbs 356
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
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ELECTRICAL COMPONENTS
347
No.FUSEAMPERECIRCUIT
26 MPX±B10
Power window system,
Air conditioning,
Gauges and meters,
Theft deterrent system
27 P RR P/W20Power window system
28 SRS±B7.5SRS system, Door lock system
29 TV7.5Television
30 OBD7.5On±board diagnosis system
31 IGN7.5
SRS system,
Multiport fuel injection
system/sequential multiport fuel
injection system,
Cruise control system
32 ECU±B120
Theft deterrent system,
Door lock system,
Interior light, Trunk light,
Vanity light, Ignition switch light,
Map light, Door courtesy lights,
Power window system,
Air conditioning,
Gauges and meters
33 ALT±S7.5Charging system
34 ETCS15Electronic throttle control
system
35 AM220
Starting system, SRS system,
Multiport fuel injection
system/sequential multiport fuel
injection system, Cruise control
system
36 HORN10Horn
No.FUSEAMPERECIRCUIT
37 RADIONO.120Audio
38 TURN±HAZ15Turn signal lights
39 EFI25
Multiport fuel injection
system/sequential multiport fuel
injection system,
Emission control system,
Engine immobiliser system
40 DRL NO.230Daytime running light system
41 DRL NO.17.5Daytime running light system
42 H±LP L LW R15Left±hand headlight
(low beam), Fog lights
43 H±LP R LW R15Right±hand headlight
(low beam)
44 ABS27.5Anti±lock brake system
45 SPARESpare fuse
46 SPARESpare fuse
47 SPARESpare fuse
48 H±LP LUPR10Left±hand headlight
(high beam)
49 H±LP R UPR10
Right±hand headlight
(high beam),
Service reminder indicators and
buzzers
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ELECTRICAL COMPONENTS
350
Checking battery condition
Checking by indicator
SV64016
Check the battery condition by the indicator color.
1BLUE ± Good condition.
2WHITE ± Charging necessary. Have the battery checked
by your Lexus dealer.
3RED ± Have the battery checked by your Lexus dealer.
NOTICE
Do not refill the battery with water.
BATTERY RECHARGINGPRECAUTIONS
During recharging, the battery is producing hydrogen
gas.
Therefore, before recharging:
1. If recharging with the battery installed on the vehicle, be
sure to disconnect the ground cable.
2. Make sure the power switch on the recharger is off when
connecting the charger cables to the battery and when
disconnecting them.
CAUTION
Always charge the battery in an unconfined area. Do
not charge the battery in a garage or closed room
where there is not sufficient ventilation.
Only do a slow charge (5 A or less). Charging at a
quicker rate is dangerous. The battery may explode
causing personal injuries.
NOTICE
Never recharge the battery while the engine is running.
Also, be sure all accessories are turned off.
2003 IS300 from Aug. '02 Prod. (OM53439U)