2003 Lexus IS300 check engine

3.
HOW TO USE THIS MANUAL
iii
HOW TO USE THIS MANUAL
The contents of this manual are explained briefly on this
page to help you make the best use of the manual. Please
read this page and the rest of the Owner's Manual
carefully to make sure you fully understand the operation
of your vehicle.
This will help you enjoy safe and comfortable driving.
TABLE OF CONTENTS
The table of contents and the pictorial index provide easy
reference to the appropriate pages.
BASIC OPERATION ± QUICK REFERENCE
Operation of basic equipment is briefly explained in an easily
understandable way for quick reference.
SECTION 1 ± INSTRUMENTS AND CONTROLS
The vehicle's equipment is divided into the 7 groups listed
below. Use of the equipment is explained, including any points
you should pay particular attention to.
1. Keys and doors
2. Switches
3. Gauges, meters and service reminder indicators
4. Interior equipment
5. Exterior equipment
6. Comfort adjustment
7. Theft deterrent
SECTION 2 ± AIR CONDITIONING AND AUDIO
The features of the vehicle's air conditioning and audio are
explained in detail. Be sure to read this section so that you can
make full use of them.
SECTION 3 ± STARTING AND DRIVING
Starting the engine, driving, stopping, operation of features
affecting vehicle handling, hints on vehicle safety and safe
driving techniques are all explained. Please read everything
in this section, and remember ± drive safely!
SECTION 4 ± IN CASE OF AN EMERGENCY
This section explains what to do in the event of an urgent
situation such as the engine not starting or getting a flat tire,
etc. If such a problem occurs, check the contents of this
Owner's Manual and follow the instructions given.
SECTION 5 ± MAINTENANCE
This section explains the importance of regular maintenance.
Regular and periodic inspection and maintenance of your
Lexus will help to keep your vehicle in its best condition.
SECTION 6 ± SERVICE PROCEDURES AND
SPECIFICATIONS
Simple maintenance procedure and service data are provided
here for your reference should you wish to perform inspection
and maintenance yourself.
2003 IS300 from Aug. '02 Prod. (OM53439U)

SWITCHES
29
Daytime Running Light System
The headlights turn on at reduced intensity when the parking
brake is released with the engine started, even with the light
switch in the ºOFFº position. They will not go off until the
ignition switch is turned off.
To turn on the other exterior lights and instrument panel lights,
twist the knob to the first clickstop.
Twist
the knob to the second clickstop to turn on the headlights
to full intensity for driving at night.
When setting the knob to the third clickstop (ºAUTOº), the
headlights will automatically adjust to full intensity and/or turn
on the other lights depending on the darkness of the
surroundings. Likewise, as the surroundings become brighter,
the headlights will turn to reduced intensity, ultimately turning
off the other lights.
NOTICE
To prevent the battery from being discharged, do not leave the lights on longer than necessary when theengine is not running.
Automatic headlight leveling system
SV12022
The headlight beam level is always maintained automatically
at the proper level in all loading conditions so that your
headlights do not dazzle other road users.
If this system fails, the warning light in the instrument cluster
comes on. If this occurs, have your vehicle checked by Lexus
dealer.
2003 IS300 from Aug. '02 Prod. (OM53439U)

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
2003 IS300 from Aug. '02 Prod. (OM53439U)

GAUGES, METERS AND SERVICE REMINDER INDICATORS
45
IF THIS INDICATOR OR
BUZZER COMES ON ...
DO THIS.
(f)Stop and check.
(g)Add engine oil.
(h)or
Take vehicle to Lexus
dealer.
(i)or
Take vehicle to Lexus
dealer.
If brake system
warning light is also
on, stop immediately
and contact Lexus
dealer.
(j)Close all doors.
IF THIS INDICATOR ORBUZZER COMES ON ...DO THIS.
(k)Replace bulb.
(l)Low fuel level
warning lightFill up tank.
(m)Take vehicle to Lexus
dealer.
(n)Take vehicle to Lexus
dealer.
(o)Take vehicle to Lexus
dealer.
(p)Key reminder buzzerRemove key.
2003 IS300 from Aug. '02 Prod. (OM53439U)

GAUGES, METERS AND SERVICE REMINDER INDICATORS
46
(a) Brake System Warning Light and Buzzer
This light comes on in the following cases when the ignition key
is in the ºONº position.
 When the parking brake is applied ...
This light comes on for a few seconds when the ignition key is
turned to the ºONº position even after the parking brake is
released.
If you drive your vehicle without releasing the parking brake,
the buzzer sounds.
 When the brake fluid level is low ...
CAUTION
It is dangerous to continue driving normally when the
brake fluid level is low.
Have your vehicle checked at your Lexus dealer in the
following cases:
The light does not come on even if the parking brake is
applied when the ignition key is in the ºONº position.
 The light does not come on even if the ignition key is turned
on with the parking brake released.
A warning light turning on briefly during operation does not
indicate a problem.
CAUTION
If either of the following conditions occurs, immediately
stop your vehicle at a safe place and contact your Lexus
dealer.
 The light does not turn off even after the parking
brake is released while the engine is running.
In the case, the brakes may not work properly and
your stopping distance will become longer. Depress
the brake pedal firmly and bring the vehicle to an
immediate stop.
 The brake system warning light remains on together
with the ºABSº warning light.
In this case, not only the anti±lock brake system will
fail but also the vehicle will become extremely
unstable during braking.
2003 IS300 from Aug. '02 Prod. (OM53439U)

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.
2003 IS300 from Aug. '02 Prod. (OM53439U)

GAUGES, METERS AND SERVICE REMINDER INDICATORS
49
(g) Low Engine Oil Level Warning Light
This light warns that the engine oil level is too low. Add oil as
soon as possible. (For instructions, see ºChecking the engine
oil levelº on page 315.)
While driving on steep inclines or rough roads which causes
the vehicle to substantially sway or on curves, this light may
come on due to the movement of engine oil in the engine.
In normal conditions, due to engine oil consumption, this light
may come on earlier than the specified service interval of the
scheduled maintenance. This is because the engine oil is
consumed to the low level within the scheduled maintenance
interval and does not indicate a problem. (For detailed
information, see ºFacts about engine oil consumptionº on page
313.)
NOTICE
Continued engine operation with low engine oil will damage the engine.
(h) Malfunction Indicator Lamp
This lamp comes on when the ignition key is turned to the
ºONº position and goes off after the engine starts. This
means that the warning light system is operating properly.
If the lamp remains on, or the lamp comes on while
driving, first check the followings. 
Empty fuel tank
If the fuel tank is empty, refuel immediately.
 Loose fuel tank cap
If the fuel tank cap is loose, securely tighten it.
These cases are temporary malfunctions. The malfunction
indicator lamp will go off after taking several driving trips.
If the lamp will not go off even after the several trips, contact
your Lexus dealer as soon as possible.
If the fuel tank is not empty or the fuel tank cap is not
loose...
 There is a problem somewhere in the engine, emission
control system, electronic throttle control system, automatic
transmission electrical system or warning light system itself.
Contact your Lexus dealer as soon as possible to service the
vehicle.
If this lamp comes on and the engine speed does not increase
with the accelerator pedal depressed down to about the middle
position, there may be a problem somewhere in your electronic
throttle control system.
At this time, if you depress the accelerator pedal more firmly
and slowly, you can drive your vehicle at low speeds. Have
your Lexus checked by your Lexus dealer as soon as possible.
Even if the abnormality of the electronic throttle control system
is corrected during low speed driving, the system may not be
recovered until the engine is stopped and the ignition key is
turned to ºACCº or ºLOCKº position.
2003 IS300 from Aug. '02 Prod. (OM53439U)

GAUGES, METERS AND SERVICE REMINDER INDICATORS
52
How to check all the service reminder
indicators
(except the low fuel level warning light):
1. Apply the parking brake.
2. Open the door.
The following service reminder indicator should come on. It
goes off when you close the door completely.
3. Turn the ignition key to ºACCº.
The following service reminder indicator should come on. It
goes off after 6 seconds.
4. Turn the ignition key to ºONº.
The following service reminder indicators should come on.


or
or

or
The following service reminder indicators go off after a few
seconds.
or

The lights other than the slip indicator light may stay on for
about 60 seconds after the engine is started. It is normal if they
go out after a while.
If any service reminder indicator or warning buzzer does not
function as described above, have it checked by your Lexus
dealer as soon as possible.
2003 IS300 from Aug. '02 Prod. (OM53439U)