1998 Lexus LS400 check engine

DRIVING TIPS
187
Trailer towing tips
When towing a trailer, your vehicle will handle differently than
when not towing. The three main causes of vehicletrailer
accidents are driver error, excessive speed and improper trailer
loading. Keep these in mind when towing:
Before starting out, check the operation of the lights and all
vehicletrailer connections. After driving a short distance, stop
and recheck the lights and connections. Practice turning,
stopping and backing with a trailer in an area away from traffic
until you learn the feel.
Backing with a trailer is difficult and requires practice. Grip the
bottom of the steering wheel and move your hand to the left to
move the trailer to the left. Move your hand to the right to move
the trailer to the right. (This procedure is generally opposite to
that when backing without a trailer.) Also, just turn the steering
wheel a little at a time, avoiding sharp or prolonged turning. Have
someone guide you when backing to reduce the risk of an
accident.
Because stopping distance may be increased, vehicletovehicle
distance should be increased when towing a trailer. For each 16
km/h (10 mph) of speed, allow at least one vehicle and trailer
length between you and the vehicle ahead. Avoid sudden braking
as you may skid, resulting in jackknifing and loss of control. This
is especially true on wet or slippery surfaces.
Avoid jerky starts or sudden acceleration.Avoid jerky steering and sharp turns. The trailer could hit your
vehicle in a tight turn. Slow down before making a turn to avoid
the need of sudden braking.
Remember that when making a turn, the trailer wheels will be
closer than the vehicle wheels to the inside of the turn. Therefore,
compensate for this by making a larger than normal turning radius
with your vehicle.
Crosswinds and rough roads will adversely affect handling of
your vehicle and trailer, causing sway. Pay attention to the rear
from time to time to prepare yourself for being passed by large
trucks or buses, which may cause your vehicle and trailer to sway.
If swaying happens, firmly grip the steering wheel and reduce
speed immediately but gradually. Never increase speed. If it is
necessary to reduce speed, brake slowly. Steer straight ahead. If
you make no extreme correction with the steering or brakes, your
vehicle and trailer will stabilize.
Be careful when passing other vehicles. Passing requires
considerable distance. After passing a vehicle, do not forget the
length of your trailer and be sure you have plenty of room before
changing lanes.
In order to maintain efficient engine braking and electrical
charging performance, do not use overdrive. Transmission must
be in the ”4” position.

DRIVING TIPS
189
HOW TO SAVE FUEL AND MAKE
YOUR VEHICLE LAST LONGER
Getting more kilometer/mileage from a liter/gallon of fuel is easy
just take it easy. It will help make your vehicle last longer, too. Here
are some specific tips on how to save money on both fuel and repairs:
Keep your tires inflated at the correct pressure. Check the
pressure every two weeks, or at least once a month.
Underinflation causes tire wear and wastes fuel.
Do not carry unneeded weight in your vehicle. Excess weight
puts a heavier load on the engine, causing greater fuel
consumption.
Avoid lengthy warmup idling. Once the engine is running
smoothly, begin driving but gently. Remember, however, that
on cold winter days this may take a little longer.
Accelerate slowly and smoothly. Avoid jackrabbit starts.
Avoid long engine idling. If you have a long wait and you are
not in traffic, it is better to turn off the engine and start again later.
Avoid engine overrevving. Use a gear position suitable for the
road on which you are traveling.
Avoid continuous speeding up and slowing down.
Stopandgo driving wastes fuel.Avoid unnecessary stopping and braking. Maintain a steady
pace. Try to time the traffic signals so you only need to stop as
little as possible or take advantage of through streets to avoid
traffic lights. Keep a proper distance from other vehicles to avoid
sudden braking. This will also reduce wear on your brakes.
Avoid heavy traffic or traffic jams whenever possible.
Do not rest your foot on the brake pedal. This causes needless
wear, overheating and poor fuel economy.
Maintain a moderate speed on highways. The faster you drive,
the greater the fuel consumption. By reducing your speed, you
will cut down on fuel consumption.
Keep the front wheels in proper alignment. Avoid hitting the
curb and slow down on rough roads. Improper alignment not only
causes faster tire wear but also puts an extra load on the engine,
which, in turn, wastes fuel.
Keep the bottom of your vehicle free from mud, etc. This not
only lessens weight but also helps prevent corrosion.
Keep your vehicle tunedup and in top shape. A dirty air
cleaner, improper valve clearance, dirty plugs, dirty oil and
grease, brakes not adjusted, etc. all lower engine performance and
contribute to poor fuel economy. For longer life of all parts and
lower operating costs, keep all maintenance work on schedule,
and if you often drive under severe conditions, see that your
vehicle receives more frequent maintenance. (For scheduled
maintenance information, please refer to the separate ”Owner’s
Manual Supplement/Maintenance Schedule”.)
CAUTION

IN CASE OF AN EMERGENCY
193
IF YOUR ENGINE STALLS WHILE
DRIVING
If your engine stalls while driving . . . .
1. Reduce your speed gradually, keeping a straight line. Move
cautiously off the road to a safe place.
2. Turn on your emergency flashers.
3. Try starting the engine again.
If the engine will not start, see ”If your vehicle will not start”.
CAUTION
If the engine is not running, the power assist for the brakes and
steering will not work, so steering and braking will be much
harder than usual.
IF YOUR VEHICLE WILL NOT
START
(a) Simple checks
Before making these checks, make sure you have followed the
correct starting procedure instructions in ”How to start the engine”
on page 159 and that you have sufficient fuel. Since your vehicle is
equipped with the engine immobiliser system, also check whether
the other keys will start the engine. If they work, your key may be
broken. Have the key checked at your Lexus dealer. If none of your
keys work, the system is possibly broken. Call your Lexus dealer.
See ”Keys” on page 8.If the engine is not turning over or is turning over too slowly
1. Check that the battery terminals are tight and clean.
2. If the battery terminals are O.K., switch on the interior light.
3. If the light is out, dim or goes out when the starter is cranked, the
battery is discharged. You may try jump starting. See ”(c) Jump
starting” for further instruction.
If the light is O.K., but the engine still will not start, it needs
adjustment or repair. Call a Lexus dealer, Roadside Assistance or
Customer Service Assistance. (See ”Foreword”.)
NOTICE
Do not pull or pushstart the vehicle. It may damage the
vehicle or cause a collision when the engine starts. Also the
threeway catalytic converter may overheat and become a fire
hazard.
If the engine turns over at its normal speed but will not start
1. The engine may be flooded because of repeated cranking. See
”(b) Starting a flooded engine” for further instructions.
2. If the engine still will not start, it needs adjustment or repair. Call
a Lexus dealer, Roadside Assistance or Customer Service
Assistance. (See ”Foreword”.)

IN CASE OF AN EMERGENCY
196
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.
IF YOUR VEHICLE OVERHEATS
If your engine coolant temperature gauge indicates overheating,
if you experience a loss of power, or if you hear a loud knocking
or pinging noise, the engine has probably overheated.
When the engine overheats
Pull safely off the road, stop the vehicle and turn on your emergency
flashers. Put the transmission in ”P” and apply the parking brake.
A: If steam is coming from your engine:
Turn off the engine. Leave the hood closed until there is no sign of
steam or coolant. Your engine could have been seriously damaged
already. Call your Lexus dealer for assistance.
CAUTION
To help avoid personal injury, keep the hood closed until there
is no steam. Escaping steam or coolant is sign of very high
pressure.

IN CASE OF AN EMERGENCY
197 B: If no steam is coming from your engine:
Leave the engine running and turn off the air conditioning. Check
the following.
Is the cooling fan operating?
Is the coolant in the acceptable range?
Is the engine drive belt O.K.?
CAUTION
When the engine is running, keep hands and clothing away
from the moving fan and engine drive belt.
Do not attempt to remove the radiator cap when the engine
and radiator are hot. Serious injury could result from
scalding hot fluid and steam blown out under pressure.
If the cooling fan is not operating or the coolant is not in the
acceptable range, turn off the engine and call your Lexus dealer.
If both conditions are O.K., after the engine coolant temperature has
cooled to normal, continue driving your vehicle.
If the engine coolant temperature does not cool down, or your
vehicle overheats again, have it checked as soon as possible by your
Lexus dealer.
IF YOU HAVE A FLAT TIRE
1. Reduce your speed gradually, keeping a straight line. Move
cautiously off the road to a safe place well away from the traffic.
Avoid stopping on the center divider of a highway. Park on a level
spot with firm ground.
2. Stop the engine and turn on your emergency flashers.
3. Firmly set the parking brake and put the transmission in ”P”.
4. Have everyone get out of the vehicle on the side away from
traffic.
5. Read the following instructions thoroughly.
NOTICE
For vehicles equipped with the height control switch, be sure to
turn the ignition switch off before jacking. If this is not done, the
vehicle height adjustment function will operate, which may
cause body damage.
CAUTION
When jacking, be sure to observe the following to reduce the
possibility of personal injury:
Follow jacking instructions.
Do not start or run the engine while your vehicle is
supported by the jack.

IN CASE OF AN EMERGENCY
210
40L026-3
2
Insert your finger, the screwdriver or equivalent into the hole
to push down the shift lock override button. You can shift the
selector lever while pushing the button.
For your safety, keep the brake pedal depressed.
Be sure to have the system checked by your Lexus dealer as soon as
possible.
IF YOU LOSE YOUR KEYS OR
LOCK YOURSELF OUT
Many Lexus dealers can make a new key if you can give them the
key number. Since your vehicle is equipped with the engine
immobiliser system, the dealer will also need your master key.
See the suggestion given in ”Keys” on page 8.
If your keys are locked in the vehicle and you cannot get a duplicate,
many Lexus dealers can still open the door for you, using their
special tools. If you must break a window to get in, we suggest
breaking the smallest side window because it is the least expensive
to replace. Be extremely cautious to avoid cuts from the glass.
Even if you lose only one key, contact your Lexus dealer to make a
new key. If you lose all your master keys, you cannot make new
keys; the whole system must be replaced.

MAINTENANCE
214Your copy of the repair order is proof that all required maintenance
has been performed for warranty coverage. And if any problems
should arise with your vehicle while under warranty, your Lexus
dealer will promptly take care of it. Again, be sure to keep a copy
of the repair order for any service performed on your Lexus.
What about doityourself maintenance?
Many of the maintenance items are easy to do yourself, if you have
a little mechanical ability and a few basic automotive tools. Simple
instructions for how to perform them are presented in Section 6.
If you are a skilled doityourself mechanic, the Lexus service
manuals are recommended. Please be aware that doityourself
maintenance can affect your warranty coverage. See your Owner’s
Guide, Owner’s Manual Supplement or Warranty Booklet for the
details.
GENERAL MAINTENANCE
Listed below are the general maintenance items that should be
performed at the intervals specified. It is recommended that any
problem you notice be brought to the attention of your Lexus dealer
or qualified service shop for their advice.
CAUTION
Make these checks only where adequate ventilation can be
obtained if you run the engine.
Vehicle exterior
Items listed below should be performed from time to time, unless
otherwise specified.
Tire pressure
Check the pressure with a gauge every two weeks, or at least once
a month and adjust as shown on the tire pressure label. See page 241
for additional information.
Tire surface
Check the tires carefully for cuts, damage or excessive wear. See
page 243 for additional information.
Wheel nuts
When checking the tires, make sure to check the nuts for looseness.
Tighten them if necessary.

MAINTENANCE
215 Tire rotation
Rotate the tires every 12000 km (7500 miles). See page 242 for
additional information.
Fluid leaks
Check underneath for leaking fuel, oil, water or other fluid after the
vehicle has been parked for a while. If you smell fuel fumes or notice
any leak, have the cause found and corrected immediately.
Doors and engine hood
Check that all doors, including trunk lid, operate smoothly and all
latches lock securely. Make sure the engine hood secondary latch
secures the hood when the primary latch is released.
Vehicle interior
Items listed below should be checked regularly, e.g. while
performing periodic services, cleaning the vehicle, etc.
Lights
Make sure the headlights, stop lights, tail lights, turn signal lights,
and other lights are working. Check headlight aim.
Service reminder indicators and warning buzzers
Check that all service reminder indicators and warning buzzers
function properly.Steering wheel
Check that it has the specified freeplay. Be alert for changes in
steering condition, such as hard steering, excessive freeplay or
strange noise.
Seats
Check that all front seat controls such as seat adjusters, seatback
recliner, etc. operate smoothly. Check that the head restraints move
up and down smoothly and that the locks hold securely in any latched
position.
Seat belts
Check that the seat belt system such as buckles, retractors and
anchors operate properly and smoothly. Make sure the belt webbing
is not cut, frayed, worn or damaged.
Accelerator pedal
Check the pedal for smooth operation and uneven pedal effort or
catching.
Brake pedal
Check the pedal for smooth operation and the proper clearance and
freeplay. Check the brake booster function.
Brakes
At a safe place, check that the brakes do not pull to one side when
applied.