check engine LEXUS LS500 2018 Workshop Manual

3896-3. Do-it-yourself maintenance
LS500_OM_OM50F54U_(U) 6
Maintenance and care before serious problems arise.
 The tire pressure detected by the
tire pressure warning system can be
displayed on the multi-information
display. ( → P.76)
 If the tire pressure drops below a
predetermined level, the driver is
warned by a screen display and a
warning light. ( → P.422)
■
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.
■
Tire inflation pressure
●
It may take a few minutes to display the
tire inflation pressure after the engine
switch is turned to IGNITION ON mode.
It may also take a few minutes to display
the tire inflation pres sure after inflation
pressure has been adjusted.
●
Tire inflation pressu re changes with tem-
perature. The displayed values may also be different from the values measured
using a tire pressure gauge. ■
Situations in which the tire pressure
warning system may not operate prop-
erly ●
In the following cases, the tire pressure
warning system may not operate prop-
erly.
• If non-genuine Lexus wheels are used.
• If a tire has been replaced with a tire that
is not an OE (Original Equipment) tire.
• If a tire has been replaced with a tire that
is not of the specified size.
• If tire chains, etc. are installed.
• An auxiliary-supported run-flat tire is
equipped.
• If a window tint that affects the radio wave
signals is installed.
• If there is a lot of snow or ice on the vehi-
cle, particularly around the wheels or
wheel housings.
• If the tire inflation pressure is much higher
than the specified level.
• If wheels not equipped with tire pressure
warning valves and transmitter are used.
• If the ID code on the tire pressure warn-
ing valves and transmitters is not regis-
tered in the tire pressure warning
computer. ●
Performance may be af fected in the fol-
lowing situations.
• When driving near a TV tower, electric
power plant, gas stat ion, radio station,
large display, airport or other facility that
generates strong radi o waves or electri-
cal noise
• When carrying a portable radio, cellular
phone, cordless phone or other wireless
communication device
If tire position information is not correctly
displayed due to the radio wave conditions,
the display may be corrected by changing
the location of the vehicle as the radio wave
conditions may change.
●
When the vehicle is stopped, the time
taken for the warning to start or turn off
may be longer.
●
When the inflation pressure of a tire
drops rapidly, for example when a tire has
burst, the warning may not operate.

402 6-3. Do-it-yourself maintenance
LS500_OM_OM50F54U_(U) 1 Turn the engine switch off.
2 Open the glove box. Remove the
partition. ( → P.336)
3 Remove the panel.
4 Unlock the filter cover ( ), pull the
filter cover out of the claws ( ),
and remove the filter cover. 5 Remove the filter case.
6 Remove the air conditioning filter
from the filter case and replace it
with a new one. The “ UP” marks shown on the filter
and the filter case sh ould be pointing up.
■
Checking interval
Inspect and replace the air conditioning fil-
ter according to the maintenance schedule.
In dusty areas or areas with heavy traffic
flow, early replacement may be required.
(For scheduled maintenance information,
please refer to the “Owner’s Manual Sup-
plement” or “Scheduled Maintenance”.)
■
If air flow from the vents decreases dra-
matically
The filter may be clogged. Check the filter
and replace if necessary.
■
Air conditioning filt er with deodorizing
function
When fragrances are placed in your vehi-
cle, the deodorizing effect may become
significantly weakened in a short period.
When an air conditioning odor comes out
continuously, replace the air conditioning Air conditioning filter The air conditioning filter must be
changed regularly to maintain air
conditioning efficiency.
Removing the air conditioning
filter
A
B

4056-3. Do-it-yourself maintenance
LS500_OM_OM50F54U_(U) 6
Maintenance and care 1 Turn the engine switch off.
2 Open the fuse box cover. 
Engine compartment: type A fuse
box Remove the service cover ( → P.379) and
push the tabs in and lift the lid off.

Engine compartment: type B fuse
box Remove the engine compartment cover
( → P.378) and push the ta bs in and lift the
lid off. 
Driver’s side instrument panel Push the tab in and remove the lid.
Make sure to push the tab in during
removal or installation.

Passenger’s side instrument panel Push the tab in and remove the lid.
Make sure to push the tab in during
removal or installation.

Trunk Remove the luggage mat. ( → P.339)
Push the tab in and lift the lid off.Checking and replacing
fuses If any of the electrical components
do not operate, a fuse may have
blown. If this happens, check and
replace the fuses as necessary.
Checking and replacing fuses

426 7-2. Steps to take in an emergency
LS500_OM_OM50F54U_(U) If it is, tighten it securely.
The light will go off after several driving
trips.
If the light does not go off even after several
trips, contact your Lexus dealer as soon as
possible. ■
Electric power steering system warning
light (warning buzzer)
When the battery charge becomes insuffi-
cient or the voltage temporarily drops, the
electric power steeri ng system warning
light may come on and the warning buzzer
may sound. ■
When the tire pressure warning light
comes on
Inspect the tires to check if a tire is punc-
tured.
If a tire is punctured: → P.432
If none of the tires are punctured:
Turn the engine switch off then turn it to
IGNITION ON mode. Check if the tire
pressure warning light comes on or blinks. 
If the tire pressure wa rning light blinks for
approximately 1 minute then stays on
There may be a malfunction in the tire
pressure warning syst em. Have the vehicle
inspected by your Lexus dealer immedi-
ately. 
If the tire pressure warning light comes
on
1 After the temperature of the tires has
lowered sufficiently, check the inflation
pressure of each tire and adjust them to
the specified level.
2 If the warning light does not turn off
even after several minutes have
elapsed, check that the inflation pres-
sure of each tire is at the specified level
and perform initialization. ( → P.392)
■
The tire pressure warning light may
come on due to natural causes
The tire pressure wa rning light may come
on due to natural causes such as natural air
leaks and tire inflation pressure changes
caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the
warning light (after a few minutes). ■
Conditions that the tire pressure warn-
ing system may not function properly
→ P.389
WARNING■
If both the ABS and the brake system
warning lights remain on
Stop your vehicle in a safe place immedi-
ately and contact your Lexus dealer.
The vehicle will become extremely
unstable during br aking, and the ABS
system may fail, which could cause an
accident resulting in death or serious
injury. ■
When the electric power steering
system warning light comes on
When the light comes on yellow, the
assist to the power st eering is restricted.
When the light comes on red, the assist
to the power steering is lost and handling
operations of the steering wheel become
extremely heavy.
When steering wheel operations are
heavier than usual, grip the steering
wheel firmly and operate it using more
force than usual. ■
If the tire pressure warning light
comes on
Be sure to observe the following precau-
tions.
Failure to do so could cause a loss of
vehicle control and result in death or
serious injury.
●
Decelerate to the lowest appropriate
speed as soon as possible. Do not
drive over 50 mph (80 km/h).
●
Check and adjust the tire inflation
pressure immediately.
●
If the tire pressure warning light comes
on even after tire inflation pressure
adjustment, it is prob able that you have
a flat tire. Have the flat tire replaced by
the nearest Lexus dealer.

430 7-2. Steps to take in an emergency
LS500_OM_OM50F54U_(U)  In some situations, the master warning light and warning buzzer may not oper-
ate as specified. In this case, follow the instructions displayed in the warning
message.
 If a warning light comes on or flashes at the same time that a warning message is
displayed, take corrective actio n according to the warning light. ( → P.418)*
: A buzzer sounds the first time a message is shown on the multi-information display.
■
Warning messages
The warning messages explained below
may differ from the actual messages
according to operation conditions and vehi-
cle specifications. ■
Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound. ■
If “Engine Oil Level Low Add or
Replace” is displayed
The engine oil level is low. Check the level
of the engine oil, and add if necessary.
This message may appear if the vehicle is
stopped on a slope. Move the vehicle to a
level surface and check to see if the mes-
sage disappears.
■
If “Engine Stoppe d Steering Power
Low” is displayed
This message is displa yed if the engine is
stopped while driving.
When steering wheel operations are
heavier than usual, grip the steering wheel
firmly and operate it using more force than
usual. ■
If “Auto Power Off to Conserve Battery”
is displayed
Power was turned off due to the automatic
power off function. Next time when starting
the engine, increase the engine speed
slightly and maintain that level for approxi-
mately 5 minutes to recharge the battery. ■
If “Headlight System Malfunction Visit
Your Dealer” is displayed
The following systems may be malfunction-
ing. Have the vehicle inspected by your
Lexus dealer immediately. ●
The LED headlight system ●
AFS (Adaptive Front-lighting System) ●
The automatic headlight leveling system ●
AHB (Automatic High Beam)
■
If “Front Camera Unav ailable” or “Front
Camera Unavailable Remove Debris
On Windshield” is displayed
The following systems may be suspended
until the problem shown in the message is
resolved. ( → P.210, 217, 424)
●
PCS (Pre-Collision system)
●
LTA (Lane Tracing Assist) (if equipped)
●
LKA (Lane Keeping Assist) (if equipped)
●
Dynamic radar cruise control with
full-speed rangeComes on Does not sound Indicates a condition, such as malfunction of electri-
cal components, their cond ition, or indicates the
need for maintenance
Flashes Does not sound Indicates a situation, such as when an operation has
been performed incorrectly, or indicates how to
perform an operation correctlyWarning buzzer *
Warning

4317-2. Steps to take in an emergency
LS500_OM_OM50F54U_(U) 7
When trouble arises ●
RSA (Road Sign Assist) (if equipped)●
AHB (Automatic High Beam)■
If “Maintenance Required Soon” is dis-
played
Indicates that all maintenance according to
the driven distance on the maintenance
schedule *
should be performed soon.
Comes on approximately 4500 miles
(7200 km) after the message has been
reset. If necessary, perform maintenance.
Please reset the message after the mainte-
nance is performed. ( → P.368)*
: Refer to the separa te “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.■
If “Maintenance Required Visit Your
Dealer” is displayed
Indicates that all maintenance is required to
correspond to the driven distance on the
maintenance schedule *
.
Comes on approximately 5000 miles
(8000 km) after the message has been
reset. (The indicator will not work properly
unless the message ha s been reset.) Per-
form the necessary maintenance. Please
reset the message after the maintenance is
performed. ( → P.368)*
: Refer to the separa te “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.
■
If “Oil Maintenance Required Soon” is
displayed
Indicates that the engine oil should be
scheduled to be changed.
Check the engine oil an d change it if neces-
sary. After changing the engine oil, make
sure to reset the message. ( → P.381)
■
If “Oil Maintenance Required” is dis-
played
Indicates that the engine oil should be
changed.
Check and change the en gine oil, and oil fil-
ter by your Lexus deal er. After changing the engine oil, make sure to reset the message.
( → P.381) ■
If “Shift System Malfunction Driving
Unavailable” is displayed
There is a malfunction in the shift control
system. Have the vehicle inspected by your
Lexus dealer immediately. ■
If a message that indicates the need for
the shift lever operation is displayed
To prevent the shift le ver from being oper-
ated incorrectly or the vehicle from moving
unexpectedly, a message that requires shift-
ing the shift position may be displayed on
the multi-information display. In that case,
follow the instruction of the message and
shift the shift position. ■
If a message that indicates the need for
visiting your Lexus dealer is displayed
The system or part shown on the
multi-information display is malfunctioning.
Have the vehicle inspected by your Lexus
dealer immediately. ■
If a message that indicates the need for
referring to Owner’ s Manual is dis-
played ●
If any of the following messages are
shown on the multi-information display,
follow the instructions.
• “Engine Coolant Temp High” ( → P.443)
•“Battery Low” ( → P.438)
• “Transmission Fluid Temp High” ( → P.164)●
If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malf unction. Have the
vehicle inspected by your Lexus dealer
immediately.
• “Access System with Elec. Key Malfunc-
tion”
• “Shift System Malfunction”
• “P Switch Malfunction”
• “Shift System Unavailable”
●
If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malfun ction. Immediately
stop the vehicle and contact your Lexus
dealer.
• “Braking Power Low”
• “Charging System Malfunction”
• “Oil Pressure Low”

434 7-2. Steps to take in an emergency
LS500_OM_OM50F54U_(U) ( → P.438)
 The battery terminal connections
may be loose or corroded.
( → P.384)
The engine starting system may be
malfunctioning due to an electrical
problem such as electronic key battery
depletion or a blown fuse. However, an
interim measure is available to start the
engine. ( → P.434)
One of the following may be the cause
of the problem:
 One or both of the battery terminals
may be disconnected. ( → P.384)
 The battery may be discharged.
( → P.438)
 There may be a malfunction in the
steering lock system. Contact your Lexus dealer if the problem
cannot be repaired, or if repair procedures
are unknown.
When the engine does not start, the
following steps can be used as an
interim measure to start the engine if
the engine switch is functioning nor- mally.
Do not use this starting procedure
except in cases of emergency.
1 Press the parking brake switch to
check that the parking brake is set.
( → P.170) Parking brake indicator will come on.
2 Turn the engine switch to ACCES-
SORY mode.
3 Press and hold the engine switch
for about 15 seconds while
depressing the brake pedal firmly.
Even if the engine can be started using
the above steps, the system may be
malfunctioning. Have the vehicle
inspected by your Lexus dealer.The starter motor does not turn
over
The starter motor does not turn
over, the interior lights and head-
lights do not turn on, or the horn
does not sound.
Starting the engine in an emer-
gency

436 7-2. Steps to take in an emergency
LS500_OM_OM50F54U_(U) ■
When the electronic key does not work
properly●
Make sure that the smart access system
with push-button start has not been dis-
abled at your Lexus dealer. If it has been
disabled, re-enable it.●
Check if battery-saving mode is set. If it is
set, cancel the function. ( → P.108)
■
Unlocking the door
Use the mechanical key ( → P.94) in
order to perform the following opera-
tions: 1 Pull the driver’s door handle and
insert the mechanical key.
2 Unlock the door.
3 Remove the key, return the handle,
and then pull the handle again. ■
Locking the door
1 With the door open, push down the
inside lock button.
2 Close the door. ■
Trunk
Turn the mechanical key clockwise to
open. ( → P.60)If the electronic key does not
operate properly If communication between the
electronic key and vehicle is inter-
rupted ( → P.108) or the electronic
key cannot be used because the
battery is depleted, the smart
access system with push-button
start and wireless remote control
cannot be used. In such cases, the
doors and trunk can be opened and
the engine can be started by follow-
ing the procedure below.
NOTICE■
In case of a smart access system with
push-button start malfunction or
other key-related problems
Take your vehicle with all the electronic
keys provided with your vehicle to your
Lexus dealer.
Locking and unlocking the
doors, unlocking the trunk

4377-2. Steps to take in an emergency
LS500_OM_OM50F54U_(U) 7
When trouble arises ■
Key linked functions
1 Closes the windows and the moon
roof *
or panoramic moon roof *

(turn and hold)
2 Opens the windows and the moon
roof *
or panoramic moon roof *

(turn and hold)These settings must be customized at your
Lexus dealer. *
:If equipped 1 Depress the brake pedal.
2 Touch the Lexus emblem side of the
electronic key to the engine switch. When the electronic key is detected, a
buzzer sounds and the engine switch will
turn to IGNITION ON mode.
When the smart access system with
push-button start is deactivated in custom-
ization setting, the engine switch will turn
to ACCESSORY mode.
3 Firmly depress the brake pedal and
check that is shown on the
multi-information display.
4 Press the engine switch.
In the event that the engine still cannot
be started, contact your Lexus dealer. ■
Stopping the engine
Set the parking brake, shift the shift position
to P and press the engine switch as you nor-
mally do when stop ping the engine.
■
Electronic key battery
As the above procedure is a temporary
measure, it is recommended that the elec-
tronic key battery be replaced immediately
when the battery is depleted. ( → P.403)
■
Changing engine switch modes
Release the brake pe dal and press the
engine switch in step 3 above. The engine
does not start and modes will be changed
each time the switch is pressed. ( → P.162)WARNING
■
When using the mechanical key and
operating the power windows or the
moon roof or panoramic moon roof
Operate the power window or the moon
roof or panoramic moon roof after
checking to make sure that there is no
possibility of any passe nger having any of
their body parts caught in the window or
the moon roof or panoramic moon roof.
Also, do not allow ch ildren to operate the
mechanical key. It is possible for children
and other passengers to get caught in
the power window or the moon roof or
panoramic moon roof. Starting the engine

444 7-2. Steps to take in an emergency
LS500_OM_OM50F54U_(U) Reservoir
“F” line
“L” line
5 Add coolant if necessary.Water can be used in an emergency if
coolant is unavailable.
 Engine →
P.444
 Intercooler Remove the engine compartment cover
and add coolant. 6 Start the engine and turn the air
conditioning system on to check
that the radiator cooling fan oper-
ates and to check for coolant leaks
from the radiator or hoses. The fan operates when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fan is operating
by checking the fan sound and air flow. If it
is difficult to check these, turn the air con-
ditioning system on and off repeatedly.
(The fan may not oper ate in freezing tem-
peratures.)
7 If the fan is not operating:
Stop the engine immediately and
contact your Lexus dealer.
If the fan is operating:
Have the vehicle inspected at the
nearest Lexus dealer. ■
When adding engine coolant
Add coolant in accordance with the follow-
ing procedure.
1 Remove the engine compartment
cover.A
B
C