check engine TOYOTA HIGHLANDER 2023 Workshop Manual

3936-3. Do-it-yourself maintenance
6
Maintenance and care
Check if the treadwear indica-
tors are showing on the tires.
Also check the tires for uneven
wear, such as excessive wear
on one side of the tread.
Check the spare tire condition
and pressure if not rotated.New tread
Worn tread
Treadwear indicator
The location of treadwear indicators
is shown by a “TWI” or “ ” mark,
WARNING
■When adding washer fluid
Do not add washer fluid when the
engine is hot or running as
washer fluid contains alcohol and
may catch fire if spilled on the
engine, etc.
NOTICE
■Do not use any fluid other
than washer fluid
Do not use soapy water or engine
antifreeze instead of washer fluid.
Doing so may cause streaking on
the vehicle’s painted surfaces, as
well as damaging the pump lead-
ing to problems of the washer
fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as
necessary.
Refer to the freezing tempera-
tures listed on the label of the
washer fluid bottle.
Tires
Replace or rotate tires in
accordance with mainte-
nance schedules and tread-
wear.
Checking tires

4086-3. Do-it-yourself maintenance
Use only Toyota wheel nuts
and wrenches designed for
use with your aluminum
wheels.
 When rotating, repairing or
changing your tires, check
that the wheel nuts are still
tight after driving 1000 miles
(1600 km).
 Be careful not to damage the
aluminum wheels when using
tire chains.
 Use only Toyota genuine bal-
ance weights or equivalent
and a plastic or rubber ham-
mer when balancing your
wheels. 1
Turn the engine switch off.
2 Open the glove box. Slide off
the damper.
3 Push in the glove box on the
vehicle’s outer side to discon-
nect the claws. Then pull out
the glove box and disconnect
the lower claws.
4 Unlock the filter cover ( ),
pull the filter cover out of the
NOTICE
●Ensure that only genuine Toyota
wheels are used on your vehi-
cle.
Tire pressure warning valves
and transmitters may not work
properly with non-genuine
wheels.
Aluminum wheel precau-
tions
Air conditioning filter
The air conditioning filter
must be changed regularly
to maintain air conditioning
efficiency.
Removing the air condi-
tioning filter

4126-3. Do-it-yourself maintenance
1Turn the engine switch off.
2 Open the fuse box cover.
Engine compartment: type A
fuse box (if equipped)
Push the tab in and lift the lid off.
Engine compartment: type B
fuse box
Push the tab in and lift the lid off.
Under the driver’s side instru-
ment panel
Remove the lid.
Make sure to push the claw when
removing/installing the lid.
3Remove the fuse.
Only type A fuse can be removed
using the pullout tool.
4Check if the fuse is blown.
Replace the blown fuse with a new
fuse of an appropriate amperage
rating. The amperage rating can be
found on the fuse box lid.
Type A
Checking and replac-
ing fuses
If any of the electrical com-
ponents do not operate, a
fuse may have blown. If this
happens, check and replace
the fuses as necessary.
Checking and replacing
fuses

4397-2. Steps to take in an emergency
7
When trouble arises
ger detection sensor may cause
the warning light to flash and the
warning buzzer to sound even if a
passenger is not sitting in the
seat.
●If a cushion is placed on the seat,
the sensor may not detect a pas-
senger, and the warning light may
not operate properly.
■SRS warning light
This warning light system monitors
the airbag sensor assembly, front
impact sensors, side impact sensors
(front), side impact sensors (front
door), side impact sensors (rear),
driver’s seat position sensor,
driver’s seat belt buckle switch, front
passenger occupant classification
system (ECU and sensors), “PASS
AIR BAG ON” indicator light, “PASS
AIR BAG OFF” indicator light, front
passenger’s seat belt buckle switch,
driver’s seat belt pretensioner, front
passenger’s seat be lt pretensioner
and force limiter, airbags, intercon-
necting wiring and power sources.
(  P.34)
■If the malfunction indicator
lamp comes on while driving
First check the following:
●Is the fuel t ank empty?
If it is, fill the f uel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go o ff after several
driving trips.
If the light does not go off even after
several trips, contact your Toyota
dealer as soon as possible.
■Electric power steering system
warning light (warning buzzer)
When the battery charge becomes
insufficient or the voltage temporar-
ily drops, the electric power steering
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
punctured.
If a tire is punctured: P. 4 4 6
If none of the tires are punctured:
Turn the engine switch off then turn
it to ON. Check if the tire pressure
warning light com es on or blinks.
If the tire pressure warning light
blinks for 1 minute then stays on
There may be a malfunction in the
tire pressure warning system. Have
the vehicle inspected by your Toyota
dealer immediately.
If the tire pressur e 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 pressure of each tire is
at the specified level and perform
initialization. ( P.399)
If the warning light d oes not turn off
several minutes af ter the initializa-
tion has been performed, have the
vehicle inspected by your Toyota
dealer immediately.
■The tire pressure warning light
may come on due to natural
causes
The tire pressure warning light may
come on due to natural causes such
as natural air leaks and tire inflation
pressure changes caused by tem-
perature. In this ca se, adjusting the
tire inflation pressure will turn off the
warning ligh t (after a few minutes).
■When a tire is replaced with a
spare tire
Vehicles with a co mpact spare tire:
The compact spare tire is not
equipped with a tire pressure warn-
ing valve and tran smitter. If a tire

4437-2. Steps to take in an emergency
7
When trouble arises
The warning lights and warning buzzers operate as follows depend-
ing on the content of the message. If a message indicates the need
for inspection by a dealer, have the vehicle inspected by your To y o t a
dealer immediately.
*: A buzzer sounds the first time a message is shown on the multi-informa-
tion display.
■Warning messages
The warning messages explained
below may differ from the actual
messages according to operation
conditions and vehicle specifica-
tions.
■Warning buzzer
In some cases, the buzzer 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 l evel surface and
check to see if the message disap-
pears.
Messages and warnings
Warning lightWarning
buzzer
*Warning
-Sounds
 Indicates an important situation, such as
when a system relate d to driving is mal-
functioning or that danger may result if
the correction procedure is not per-
formed
 Indicates a situation, such as when dam-
age to the vehicle or danger may result
Comes on or
flashesSounds
Indicates an importan t situation, such as
when the systems shown on the
multi-information display may be malfunc-
tioning
-Does not sound
 Indicates a condition, such as malfunc-
tion of electrical components, their condi-
tion, or indicates the need for
maintenance
 Indicates a situatio n, such as when an
operation has been performed incor-
rectly, or indicates how to perform an
operation correctly

4457-2. Steps to take in an emergency
7
When trouble arises
●PCS (Pre-Collision system)
●LTA (Lane Tracing Assist)
●Dynamic radar cruise control with
full-speed range
■If “AWD System Overheated
Switching to 2WD Mode” or
“AWD System Overheated 2WD
Mode Engaged” is displayed
This message may be displayed
when driving under extremely high
load conditions.
Drive the vehicle at low speeds or
stop the vehicle in a safe place with
the engine running until the mes-
sage is cleared.
If the message is not cleared, have
the vehicle inspected by your Toyota
dealer.
■If “Check Fuel Cap” is dis-
played
The fuel tank cap is not properly
installed. Correctly install the fuel
tank cap.
■If “Maintenance Required
Soon” is displayed
Indicates that all maintenance
according to the dr iven distance on
the maintenance schedule
* should
be performed soon.
Comes on approximately 4500
miles (7200 km) after the message
has been reset. If necessary, per-
form maintenance. Please reset the
message after the maintenance is
performed. ( P.377)
*: Refer to the separate “Scheduled
Maintenance Guide” or “Owner’s
Manual Supplement” for the main-
tenance 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 sched-
ule
*. Comes on approximately 5000
miles (8000 km) after the message
has been reset. (The indicator will
not work properly unless the mes-
sage has been rese
t.) Perform the
necessary maintenance. Please
reset the message after the mainte-
nance is performed. ( P.377)
*: Refer to the separate “Scheduled
Maintenance Guide” or “Owner’s
Manual Supplement” for the main-
tenance 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 and change it if
necessary. After changing the
engine oil, make sure to reset the
message. ( P.388)
■If “Oil Maintenance Required” is
displayed
Indicates that the engine oil should
be changed.
Check and change the engine oil,
and oil filter by your Toyota dealer.
After changing the engine oil, make
sure to reset t he message.
(  P.388)
■If a message that indicates the
need for visiting your Toyota
dealer is displayed
The system or part shown on the
multi-information di splay is malfunc-
tioning. Have the vehicle inspected
by your Toyota dealer immediately.
■If a message that indicates the
need for referring to Owner’s
Manual is displayed
●If any of the following messages
are shown on the multi-informa-
tion display, it may indicate a mal-
function. Immediately stop the
vehicle and contact your Toyota
dealer.
• “Braking Power Low Stop in a Safe Place See Owner's Manual”

4617-2. Steps to take in an emergency
7
When trouble arises
functioning normally.
Do not use this starting proce-
dure except in cases of emer-
gency.
1Pull the parking brake switch
to check that the parking
brake is set. ( P.205)
Parking brake indicator will come
on.
2 Shift the shift lever to P.
3 Turn the engine switch to
ACC.
4 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 malfunction-
ing. Have the vehicle inspected
by your Toyota dealer.
If you lose your keys
New genuine mechanical
keys can be made by your
Toyota dealer using another
mechanical key and the key
number stamped on your
key number plate.
Keep the plate in a safe
place such as your wallet,
not in the vehicle.
NOTICE
■When an electronic key is lost
If the electronic key remains lost,
the risk of vehicle theft increases
significantly. Visit your Toyota
dealer immediately with all
remaining electronic keys that
were provided with your vehicle.

4637-2. Steps to take in an emergency
7
When trouble arises
■When the electronic key does
not work properly
●Make sure that the smart key sys-
tem has not been deactivated in
the customization setting. If it is
off, turn the function on. (Custom-
izable features: P.494)
●Check if battery-saving mode is
set. If it is set, cancel the function.
( P.133)
■Unlocking the door
Use the mechanical key
( P.114) in order to perform the
following operations: 1
Locks all the doors
2 Unlocks all the doors
Turning the key unlocks the driver’s
door. Turning the key again unlocks
the other doors.
■Key linked functions
1 Closes the windows and the
moon roof
* (turn and hold)
2 Opens the windows and the
moon roof
* (turn and hold)
These settings mus t be customized
at your Toyota dealer.
*: If equipped
If the electronic key
does not operate prop-
erly
If communication between
the electronic key and vehi-
cle is interrupted ( P.133)
or the electronic key cannot
be used because the battery
is depleted, the smart key
system and wireless remote
control cannot be used. In
such cases, the doors can
be opened and the engine
can be started by following
the procedure below.
Locking and unlocking
the doors

4647-2. Steps to take in an emergency
1Ensure that the shift lever is
in P and depress the brake
pedal.
2 Touch the Toyota 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 ON.
When the smart key system is
deactivated in customization set-
ting, the engine switch will turn to
ACC.
3Firmly depress the brake
pedal and check that is shown on the multi-informa-
tion display.
4 Press the engine switch
shortly and firmly.
In the event that the engine still
cannot be started, contact your
Toyota dealer.
■Stopping the engine
Shift the shift lever to P, set the park-
ing brake, and press the engine
switch as you normally do when
stopping the engine.
■Replacing the key battery
As the above proce dure is a tempo-
rary measure, it is recommended
that the electronic key battery be
replaced immediately when the bat-
tery is depleted. ( P.410)
■Changing engine switch modes
Release the brake pedal 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.199)
WARNING
■When using the mechanical
key and operating the power
windows or moon roof (if
equipped)
Operate the power window or
moon roof after checking to make
sure that there is n o possibility of
any passenger having any of their
body parts caught in the window
or moon roof. Al so, do not allow
children to operate the mechani-
cal key. It is possible for children
and other passengers to get
caught in the power window or
moon roof.
Starting the engine

4707-2. Steps to take in an emergency
hoses and radiator core (radi-
ator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant leaks,
immediately contact your Toyota
dealer.
4 The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator cap
5 Add coolant if necessary.
Water can be used in an emer- gency if coolant is unavailable.
6
Start the engine and turn the
air conditioning system on to
check that the radiator cool-
ing fan operates and to check
for coolant leaks from the
radiator or hoses.
The fan operates when the air con-
ditioning system is turned on imme-
diately after a cold start. Confirm
that the fan is operating by check-
ing the fan sound and air flow. If it is
difficult to check these, turn the air
conditioning system on and off
repeatedly. (The fan may not oper-
ate in freezing temperatures.)
7If the fan is not operating:
Stop the engine immediately
and contact your Toyota
dealer.
If the fan is operating:
Have the vehicle inspected at
the nearest Toyota dealer.
8 Check if “Engine Coolant
Temp High Stop in a Safe
Place See Owner's Manual”
is shown on the multi-infor-
mation display.
If the message does not disappear:
Stop the engine and contact your
Toyota dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Toyota dealer.