check engine TOYOTA HIGHLANDER 2021 (in English) Workshop Manual

4386-3. Do-it-yourself maintenance
HIGHLANDER_U
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

4667-2. Steps to take in an emergency
HIGHLANDER_Udealer 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.472 If none of the tires are punctured:
Turn the engine switch off then turn
it to ON. Check if the tire pressure
warning light comes 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 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 pressure of each tire is
at the specified level and perform
initialization. ( P.426)
If the warning light does not turn off
several minutes after 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 case, adjusting the
tire inflation pressure will turn off the
warning light (afte
r a few minutes).
■When a tire is replaced with a
spare tire
Vehicles with a compact spare tire:
The compact spare tire is not
equipped with a tire pressure warn-
ing valve and transmitter. If a tire
goes flat, the tire pressure warning
light will not turn off even though the
flat tire has been replaced with the
spare tire. Replace the spare tire
with the repaired tire and adjust the
tire inflation pressure. The tire pres-
sure warning light will go off after a
few minutes.
Vehicles with a full-size spare tire:
The spare tire is also equipped with
a tire pressure warning valve and
transmitter. The ti re pressure warn-
ing light will turn on if the tire infla-
tion pressure of the spare tire is low.
If a tire goes flat, the tire pressure
warning light will not turn off even
though the flat tire has been
replaced with the spare tire.
Replace the spare tire with the
repaired tire and adjust the tire infla-
tion pressure. The tire pressure
warning light will go off after a few
minutes.
■Conditions that the tire pres-
sure warning system may not
function properly
 P.422
WARNING
■If both the ABS and the brake
system warning lights remain
on
Stop your vehicle in a safe place
immediately and contact your Toy-
ota dealer.
The vehicle will become
extremely unstable during brak-
ing, and the ABS system may fail,
which could cause an accident
resulting in death or serious injury.

4697-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER_U
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 Toyota
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 level 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 important situation, such as
when the systems shown on the
multi-information disp lay 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 situation, such as when an
operation has been performed incor-
rectly, or indicates how to perform an
operation correctly

4707-2. Steps to take in an emergency
HIGHLANDER_U
■If “Engine Stopped Steering
Power Low” is displayed
This message is displayed 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 “Shift to P when Parked” is
displayed
This message is displayed when the
driver’s door is opened without turn-
ing the engine switch off with the
shift lever in any position other than
P. Change the shift lever to P.
■If “Auto Power OFF to Conserve
Battery” is displayed
Power was cut off due to the auto-
matic power off function. Next time
when starting the engine, increase
the engine speed slightly and main-
tain that level for approximately 5
minutes to recharge the battery.
■If “Headlight System Malfunc-
tion Visit Your Dealer” is dis-
played
The following systems may be mal-
functioning. Have the vehicle
inspected by your Toyota dealer
immediately.
●The LED headlight system (if AFS
[Adaptive Front-lighting System]
equipped)
●AFS (Adaptive Front-lighting Sys-
tem) (if equipped)
●The automatic headlight leveling
system (if equipped)
●Automatic High Beam
■If “Radar Cruise Control
Unavailable” is displayed
The dynamic radar cruise control
with full-speed range system cannot
be used temporarily. Use the system
when it becomes available again.
■If a message that indicates the
malfunction of front camera is
displayed
The following systems may be sus-
pended until the problem shown in
the message is resolved. ( P.233,
464)
●PCS (Pre-Collision system)
●LTA (Lane Tracing Assist)
●Automatic High Beam
●RSA (Road Sign Assist) (if
equipped)
●Dynamic radar cruise control with
full-speed range
■If a message that indicates the
malfunction of radar sensor is
displayed
The following systems may be sus-
pended until the problem shown in
the message is resolved. ( P.233,
464)
●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
(AWD models)
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 inspect ed by your Toyota
dealer.
■If “Check Fuel Cap” is dis-
played
The fuel tank cap is not properly
installed. Correctl y install the fuel
tank cap.

4717-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER_U
■If “Maintenance Required
Soon” is displayed
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, per-
form maintenance. Please reset the
message after the maintenance is
performed. ( P.403)
*: 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 reset.) Perform the
necessary maintenance. Please
reset the message after the mainte-
nance is performed. ( P.403)
*: 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.414)
■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 the message.
(  P.414)
■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”
• “Oil Pressure Low Stop in a Safe
Place See Owner's Manual”
• “Charging System Malfunction Stop in a Safe Place See Owner's
Manual”
●If “Smart Key System Malfunction
See Owner's Manual” is shown on
the multi-information display, it
may indicate a malfunction. Have
the vehicle inspected by your Toy-
ota dealer immediately.
●If any of the following messages
are shown on the multi-informa-
tion display, follow the instruc-
tions.
• “Engine Coolant Temp High Stop in a Safe Place See Owner's Man-
ual” ( P.495)
• “High Transmission Fluid Temp See Owner's Manual” ( P.206)

4837-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER_U
7Confirm it is not loose after
tightening:
1 Push and pull the tire
2 Try rotating
Visually check to ensure tire is not
hung on surrounding parts.
If looseness or misassembly exists,
repeat steps 2 to 7 .
8Repeat step 7, any time the
tire is lowered or disturbed.
9 Stow the jack and all tools.
■The compact spare tire (vehi-
cles with a compact spare tire)
●The compact spare tire is identi-
fied by the label “TEMPORARY
USE ONLY” on the tire sidewall.
Use the compact spare tire tempo-
rarily, and only in an emergency.
●Make sure to che ck the tire infla-
tion pressure of the compact
spare tire. ( P.505)
■When using the compact spare
tire (vehicles with a compact
spare tire)
As the compact spare tire is not
equipped with a tire pressure warn-
ing valve and transmitter, low infla-
tion pressure of the spare tire will
not be indicated by the tire pressure
warning system. Also, if you replace
the compact spare tire after the tire
pressure warning light comes on,
the light remains on.
■When the compact spare tire is
equipped (vehicles with a com-
pact spare tire)
When driving with the compact
spare tire installed, the vehicle
height will be different than when
driving with standard tires.
■If you have a flat front tire on a
road covered with snow or ice
(vehicles with a compact spare
tire)
Install the compact spare tire on one
of the rear wheels of the vehicle.
Perform the following steps and fit
tire chains to the front tires:
1 Replace a rear tire with the com-
pact spare tire.
2 Replace the flat front tire with the
tire removed from the rear of the
vehicle.
3 Fit tire chains to the front tires.
WARNING
■When using the compact
spare tire (vehicles with a
compact spare tire)
●Remember that the compact
spare tire provided is specifi-
cally designed for use with your
vehicle. Do not use your com-
pact spare tire on another vehi-
cle.
●Do not use more than one com-
pact spare tire simultaneously.
●Replace the compact spare tire
with a standard tire as soon as
possible.
●Avoid sudden acceleration,
abrupt steering, sudden brak-
ing and shifting operations that
cause sudden engine braking.

4877-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER_U
as an interim measure to start
the engine if the engine switch is
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.211)
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.

4897-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER_U
■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.521)
●Check if battery-saving mode is
set. If it is set, cancel the function.
( P.135)
■Unlocking the door
Use the mechanical key
( P.116) 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 must 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.135)
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

4907-2. Steps to take in an emergency
HIGHLANDER_U
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 procedure is a tempo-
rary measure, it is recommended
that the electronic key battery be
replaced immediately when the bat-
tery is depleted. ( P.436)
■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.205)
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 no possibility of
any passenger having any of their
body parts caught in the window
or moon roof. Also, 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

4967-2. Steps to take in an emergency
HIGHLANDER_U
hoses and radiator core (radi-
ator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant leaks,
immediately contact your Toyota
dealer.
4The 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.