1998 Lexus LS400 check engine

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 af fecting
vehicle handling, hints on vehicle safety and safe driving techniques
are all explained. Please read ev erything 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 impor tance 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 wi sh to perform inspection and
maintenance yourself.

SWITCHES
23 Daytime Running Light System (Canada only)
The headlights turn on when the parking brake is released with the
engine started, even with the light switch in the ”OFF” 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.
Under the daytime running light system, the headlights turn on at
reduced intensity. Twist the knob to the second clickstop to turn to
full intensity for driving at night.
When setting the knob to the third clickstop (”AUTO”), 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 the engine is not running.
Automatic headlight leveling system (Vehicles with
discharge headlight only)
As the headlight beam level is always maintained automatically at
the proper level in all loading conditions, your headlights do not
dazzle other road users.
If this system fails, the multi information display shows a message
”HEADLIGHT LEVELING”. If this occurs, have your vehicle
checked by Lexus dealer.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
39
(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) Malfunction Indicator Lamp
This lamp comes on in the following cases.
a. The fuel tank is completely empty. (See ”Fuel gauge” on page 34
for instructions.)
b. The fuel tank cap is not tightened securely. (See ”Fuel tank cap”
on page 65 for instructions.)
c. There is a problem somewhere in your engine electrical system
or electronic throttle control system.
If it comes on while you are driving in case c., have your vehicle
checked/repaired by your Lexus dealer as soon as possible.
(g) ”ABS” Warning Light
This light warns that there is a problem somewhere in your antilock
brake system.
If the light comes on while you are driving, have your vehicle
checked by your Lexus dealer as soon as possible.
The light will come on when the ignition key is turned to ”ON”, and
will go off after about a few seconds.
When the ”ABS” warning light is on (and the brake system warning
light is off), the brake system operates conventionally but antilock
brake system is not assisting brake performance so that the wheels
could lock up during a sudden brake or braking on slippery road
surfaces.
(h) Open Door Warning Light
This light remains on until all the doors are completely closed.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
44
(b) Warning messages
13L052
Reminder light
W40
W40
When the engine oil pressure becomes too low, the above
message appears, the reminder light flashes and the warning
tone sounds.
If this message appears 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 message may appear 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 message displayed
even for one block. It may ruin the engine.
W41 W41
When your brake pads are worn enough to require replacement,
the above message appears, the reminder light flashes and the
warning tone sounds.
If this message appears while you are driving, have the brake pads
checked and replaced by your Lexus dealer as soon as possible.
W43 W43
W42
W42
W451
W44
W44
W46
W46
When any door or trunk is open with the ignition switch turned
on, the message which door or trunk is open appears, and the
reminder light comes on.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
45 If you continue driving with any door or trunk open, the reminder
light starts flashing and the warning tone sounds to remind you to
close the door or trunk.
W52 W52
If the driver’s door is opened with the ignition switch turned off
and the moon roof opened, the above message appears and the
reminder light flashes.
W48 W48
In the following cases, the warning message appears and the
reminder light next to the warning message and the ”VSC OFF”
indicator light come on. And the warning tone also sounds.
(a) After the removal of the battery terminals (See ”Initial
adjustment of vehicle skid control system” on page 175.)
(b) If the vehicle skid control system malfunctions
If the above message appears for the cause of (b), have your vehicle
checked by your Lexus dealer as soon as possible.
Although the above message appears, you can continue your normal
driving, but without the vehicle skid control system function.
W49 W49
In the following cases, the above message appears, the reminder
light comes on and the warning tone sounds.
When the headlight switch is turned to the first or second
clickstop with one or more of tail light bulbs burned out.
When the brake pedal is held down with one or more of stop light
bulbs burned out.
Have defective bulbs replaced as soon as possible.
W50 W50
When the engine oil level is too low, the above message appears,
the reminder light comes on and the warning tone sounds.
Add oil as soon as possible. (For instructions, see ”Checking the
engine oil level” on page 230.)
NOTICE
Continued engine operation with low engine oil will damage the
engine.

STARTING AND DRIVING
155
THREEWAY CATALYTIC
CONVERTER
31L0022
Threeway catalytic converters are emission control devices
installed in the exhaust system.
It looks somewhat like a muffler, but its purpose is to reduce
pollutants in the exhaust gas.
CAUTION
Keep people and combustible materials away from the
exhaust pipe while the engine is running. The exhaust gas
is very hot.
Do not drive, idle or park your vehicle over anything that
might burn easily such as grass, leaves, paper or rags.
NOTICE
A large amount of unburned gases flowing into the threeway
catalytic converter may cause it to overheat and create a fire
hazard. To prevent this and other damage, observe the following
precautions:
Use only unleaded gasoline.
Do not drive with an extremely low fuel level; running out of
fuel could cause the engine to misfire, creating an excessive
load on the threeway catalytic converter.
Do not allow the engine to run at idle speed for more than 20
minutes.
Avoid racing the engine.
Do not pushstart or pullstart your vehicle.
Do not turn off the ignition while the vehicle is moving.
Keep your engine in good running order. Malfunctions in the
engine electrical system, electronic ignition
system/distributor ignition system or fuel system could cause
an extremely high threeway catalytic converter
temperature.
If the engine becomes difficult to start or stalls frequently,
take your vehicle in for a checkup as soon as possible.
Remember, your Lexus dealer knows your vehicle and its
threeway catalytic converter system best.

STARTING AND DRIVING
156To ensure that the threeway catalytic converter and the
entire emission control system operate properly, your vehicle
must receive the periodic inspections required by the Lexus
Maintenance Schedule. For scheduled maintenance
information, refer to the separate ”Owner’s Manual
Supplement/ Maintenance Schedule”.
ENGINE EXHAUST CAUTION
CAUTION
Avoid inhaling the engine exhaust. It contains carbon
monoxide, which is a colorless and odorless gas. It can
cause unconsciousness or even death.
Make sure the exhaust system has no holes or loose
connections. The system should be checked from time to
time. If you hit something, or notice a change in the sound
of the exhaust, have the system checked immediately.
Do not run the engine in a garage or enclosed area except
for the time needed to drive the vehicle in or out. The
exhaust gases cannot escape, making this a particularly
dangerous situation.
Do not remain for a long time in a parked vehicle with the
engine running. If it is unavoidable, however, do so only in
an unconfined area and adjust the heating or cooling
system to force outside air into the vehicle.
Keep the trunk lid closed while driving. An open or
unsealed trunk lid may cause exhaust gases to be drawn
into the vehicle. If you must drive with the trunk lid open
to accommodate a large object, close the windows, open all
the dashboard vents and have the heating or cooling system
deliver fresh air into the vehicle by turning the fan to high
speed with the air intake control button in the OUTSIDE
AIR mode.
To allow proper operation of your vehicle’s ventilation
system, keep the inlet grilles in front of the windshield clear
of snow, leaves, or other obstructions.
If you smell exhaust fumes in the vehicle, drive with the
windows open and the trunk lid closed. Have the cause
immediately located and corrected.

STARTING AND DRIVING
157
BEFORE STARTING THE ENGINE
1. Check the area around the vehicle before entering it.
2. Adjust seat position, seatback angle, head restraint height and
steering wheel angle.
3. Adjust inside and outside rear view mirrors.
4. Lock all doors.
5. Fasten seat belts.
Remember to check that the service reminder indicators function
when turning the key to ”ON”, and check the fuel gauge to see that
you have sufficient fuel.
IGNITION SWITCH WITH
STEERING LOCK
31L0011
”START” Starter motor on. The key will return to the ”ON”
position when released.
For starting tips, see page 159.
”ON” Engine on and all accessories on.
This is the normal driving position.
NOTICE
Do not leave the key in the ”ON” position if the engine is not
running. The battery will discharge and the electronic ignition
system/distributor ignition system could be damaged.
”ACC” Accessories such as the radio operate, but the engine
is off.
If you leave the key in the ”ACC” or ”LOCK” position and open the