check engine TOYOTA HIGHLANDER 2023 Service Manual

3766-2. Maintenance
6-2.Maintenance
■Repair and replacement
It is recommended that genuine
Toyota parts be used for repairs to
ensure performanc e of each sys-
tem. If non-Toyota parts are used in
replacement or if a repair shop other
than a Toyota dealer performs
repairs, confirm the warranty cover-
age.
■Allow inspection and repairs to
be performed by a Toyota
dealer
●Toyota technicians are
well-trained specialists and are
kept up to date with the latest ser-
vice information. They are well
informed about the operation of all
systems on your vehicle.
●Keep a copy of the repair order. It
proves that the maintenance that
has been performed is under war-
ranty coverage. If any problem
should arise while your vehicle is
under warranty, your Toyota
dealer will promptly take care of it.
General maintenance should be
performed on a daily basis. This
can be done by yourself or by a
Toyota dealer.
Scheduled maintenance should
be performed at specified inter-
vals according to the mainte-
nance schedule.
For details about maintenance
items and schedules, refer to the
“Scheduled Maintenance Guide” or
“Owner’s Manual Supplement”.
Maintenance require-
ments
To ensure safe and econom-
ical driving, day-to-day care
and regular maintenance
are essential. It is the
owner’s responsibility to
perform regular checks.
Toyota recommends the fol-
lowing maintenance:
WARNING
■If your vehicle is not properly
maintained
Improper maintenance could
result in serious damage to the
vehicle and possible death or seri-
ous injury.
■Handling of the battery
●Engine exhaust, some of its
constituents, and a wide variety
of automobile components con-
tain or emit chemicals known to
the State of California to cause
cancer and birth defects and
other reproductive harm. Work
in a well ventilated area.
●Oils, fuels and fluids contained
in vehicles as well as waste pro-
duced by component wear con-
tain or emit chemicals known to
the State of California to cause
cancer and birth defects or
other reproductive harm. Avoid
exposure and wash any
affected area immediately.
●Battery posts, terminals and
related accessories contain lead
and lead compounds which are
known to cause brain damage.
Wash your hands after han-
dling. ( P.391)
General maintenance
Scheduled maintenance

3786-2. Maintenance
General maintenance
Listed below are the general
maintenance items that
should be performed at the
intervals specified in the
“Owner’s Warranty Informa-
tion Booklet” or “Owner’s
Manual Supplement/Sched-
uled Maintenance Guide”. It
is recommended that any
problem you notice should
be brought to the attention
of your Toyota dealer or
qualified service shop for
advice.
WARNING
■If the engine is running
Turn the engine off and ensure
that there is adequate ventilation
before performing maintenance
checks.
Engine compartment
ItemsCheck points
BatteryCheck the connec-
tions. ( P.391)
Brake fluid
Is the brake fluid at
the correct level?
( P.390)
Engine coolant
Is the engine cool-
ant at the correct
level? ( P.389)
Engine oil
Is the engine oil at
the correct level?
( P.386)
Exhaust sys-
temThere should not
be any fumes or
strange sounds.
Radiator/con-
denser
The radiator and
condenser should
be free from for-
eign objects.
( P.390)
Washer fluid
Is there sufficient
washer fluid?
( P.392)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should
move smoothly
(without uneven
pedal effort or
catching).
Automatic
transmission
“Park” mecha-
nism
• When parked on a slope and the
shift lever is in P,
is the vehicle
securely
stopped?
ItemsCheck points

3806-2. Maintenance
The OBD system determines
that a problem exists some-
where in the emission control
system. Your vehicle may not
pass the I/M test and may need
to be repaired. Contact your
Toyota dealer to service the
vehicle.
When the battery is discon-
nected or discharged
Readiness codes that are set
during ordinary driving are erased.
Also, depending on your driving
habits, the readiness codes may
not be completely set.
When the fuel tank cap is
loose
Vehicle exterior
ItemsCheck points
Doors
• Do the doors
operate
smoothly?
Engine hood
• Does the engine hood lock system
work properly?
Fluid leaks
• There should not be any signs of
fluid leakage
after the vehicle
has been parked.
Tires
• Is the tire infla-tion pressure
correct?
• The tires should not be damaged
or excessively
worn.
• Have the tires been rotated
according to the
maintenance
schedule?
• The wheel nuts should not be
loose.
Windshield
wipers/rear
window wiper
• The wiper blades should not show
any signs of
cracking, split-
ting, wear, con-
tamination or
deformation.
• The wiper blades should clear the
windshield/rear
window without
streaking or skip-
ping.
Emission inspection
and maintenance (I/M)
programs
Some states have vehicle
emission inspection pro-
grams which include OBD
(On Board Diagnostics)
checks. The OBD system
monitors the operation of
the emission control sys-
tem.
If the malfunction indica-
tor lamp comes on
Your vehicle may not pass
the I/M test in the follow-
ing situations:

3846-3. Do-it-yourself maintenance
1Pull the hood lock release
lever.
The hood will pop up slightly.
2Pull up the auxiliary catch
lever and lift the hood.
3 Hold the hood open by insert-
ing the support rod into the
slot.
Hood
Opening the hood
WARNING
■Pre-driving check
Check that the hood is fully closed
and locked.
If the hood is not locked properly,
it may open while the vehicle is in
motion and cause an accident,
which may result i n death or seri-
ous injury.
■To prevent a injuries
The support rod may be hot after
driving the vehicle. Touching the
hot support rod may lead to burns
or other serious injuries.
■After installing the support
rod into the slot
Make sure the rod supports the
hood securely preventing it from
falling down onto your head or
body.
NOTICE
■When the hood is open
Even if the engine switch is turned
off, the cooling fan may continue
to operate for a short time. When
the cooling fan is rotating, do not
touch or approac h the inside of
the engine compartment.
■When closing the hood
Be sure to return the support rod
to its clip before closing the hood.
Closing the hood with the support
rod not clipped could cause the
hood to bend.

3866-3. Do-it-yourself maintenance
Engine coolant reservoir ( P.389)
Fuse boxes ( P.412)
Engine oil filler cap ( P.387)
Engine oil level dipstick ( P.386)
Battery ( P.391)
Brake fluid reservoir ( P.390)
Washer fluid tank ( P.392)
Electric cooling fan
Condenser ( P.390)
Radiator ( P.390)
With the engine at operating
temperature and turned off,
check the oil level on the dip- stick.
■Checking the engine oil
1 Park the vehicle on level
ground. After warming up the
engine and turning it off, wait
Engine compar tment
Components
Checking and adding the
engine oil

3876-3. Do-it-yourself maintenance
6
Maintenance and care
more than 5 minutes for the
oil to drain back into the bot-
tom of the engine.
2 Holding a rag under the end,
pull the dipstick out.
3 Wipe the dipstick clean.
4 Reinsert the dipstick fully.
5 Holding a rag under the end,
pull the dipstick out and
check the oil level.
Low
Normal
Excessive
The shape of the dipstick may differ
depending on the type of vehicle or
engine.
6Wipe the dipstick and reinsert
it fully.
■Checking the oil type and
preparing the item needed
Make sure to check the oil type
and prepare the items needed
before adding oil.
 Engine oil selection
P.476
 Oil quantity (Low  Full)
1.9 qt. (1.8 L, 1.6 Imp. qt.)
 Item
Clean funnel
■Adding engine oil
If the oil level is below or near
the low level mark, add engine
oil of the same type as that
already in the engine.
1 Remove the oil filler cap by
turning it counterclockwise.
2 Add engine oil slowly, check-
ing the dipstick.
3 Install the oil filler cap by
turning it clockwise.
■Engine oil consumption
A certain amount of engine oil will
be consumed while driving. In the
following situatio ns, oil consump-
tion may increase, and engine oil
may need to be refilled in between
oil maintenance intervals.

3886-3. Do-it-yourself maintenance
●When the engine is new, for
example directly after purchasing
the vehicle or after replacing the
engine
●If low quality oil or oil of an inap-
propriate viscosity is used
●When driving at high engine
speeds or with a heavy load,
when towing, or when driving
while accelerating o r decelerating
frequently
●When leaving the engine idling for
a long time, or wh en driving fre-
quently through heavy traffic
■If the oil is spilled on the engine
cover
To prevent the engine cover from
being damaged, remove any engine
oil from the engine cover as soon as
possible using a neutral detergent.
Do not use an organic solvent such
as brake cleaner.
■After changing the engine oil
The engine oil maintenance data
should be reset. Perform the follow-
ing procedures:
7-inch display
1 Select of the multi-informa-
tion display.
2 Press or of the meter
control switch, select and
then press and hold .
3 Press or of the meter
control switch, se lect “Oil Mainte-
nance” and then press .
4 Select “Yes” and press .
5 A message will be displayed on
the multi-information display
when the reset procedure has
been completed.
12.3-inch display
1 Select of the multi-informa-
tion display. 2
Press or of the meter
control switch, select and
then press and hold .
3 Press or of the meter
control switch, select “Oil Mainte-
nance” and then press .
4 Select “Yes” and press .
5 A message will be displayed on
the multi-inform ation display
when the reset procedure has
been completed.
WARNING
■Used engine oil
●Used engine oil contains poten-
tially harmful contaminants
which may cause skin disorders
such as inflammation and skin
cancer, so care should be taken
to avoid prolonged and
repeated contact. To remove
used engine oil from your skin,
wash thoroughly with soap and
water.
●Dispose of used oil and filters
only in a safe and acceptable
manner. Do not dispose of used
oil and filters in h ousehold trash,
in sewers or onto the ground.
Call your Toyota dealer, service
station or auto parts store for
information concerning recy-
cling or disposal.
●Do not leave used engine oil
within the reach of children.
NOTICE
■To prevent serious engine
damage
Check the oil le vel on a regular
basis.

3896-3. Do-it-yourself maintenance
6
Maintenance and careThe coolant level is satisfactory
if it is between the “FULL” and
“LOW” lines on the reservoir
when the engine is cold.Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL” line. (
P.469)
■Coolant selection
Only use “Toyota Super Long Life
Coolant” or a similar high quality
ethylene glycol ba sed non-silicate,
non-amine, non-nitrite, and
non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is
a mixture of 50% c oolant and 50%
deionized water. (Minimum tem-
perature: -31°F [-35°C])
Canada:
“Toyota Super Long Life Coolant” is
a mixture of 55% c oolant and 45%
deionized water. (Minimum tem-
perature: -44°F [-42°C])
For more details about coolant, con-
tact your Toyota dealer.
■If the coolant level drops within
a short time of replenishing
Visually check the radiator, hoses,
engine coolant reservoir cap, drain
cock and water pump.
If you cannot find a leak, have your
Toyota dealer test the cap and
check for leaks in the cooling sys-
tem.
NOTICE
■When replacing the engine oil
●Be careful not to spill engine oil
on the vehicle components.
●Avoid overfilling, or the engine
could be damaged.
●Check the oil le vel on the dip-
stick every time you refill the
vehicle.
●Be sure the engine oil filler cap
is properly tightened.
■If oil is spilled on the engine
cover
To prevent the engine cover from
being damaged, remove any
engine oil from the engine cover
as soon as possible using a neu-
tral detergent. Do not use an
organic solvent such as brake
cleaner.
Checking the coolant
WARNING
■When the engine is hot
Do not remove the engine coolant
reservoir cap and radiator cap.
The cooling system may be under
pressure and may spray hot cool-
ant if the cap is removed, causing
serious injuries, such as burns.

3906-3. Do-it-yourself maintenance
Check the radiator and con-
denser and clear away any for-
eign objects. If either of the
above parts is extremely dirty or
you are not sure of their condi-
tion, have your vehicle
inspected by your Toyota dealer.
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
lines on the tank.
■Adding fluid
Make sure to check the fluid
type and prepare the necessary
item.
 Fluid type
SAE J1703 or FMVSS No.116 DOT
3 brake fluid
SAE J1704 or FMVSS No.116 DOT
4 brake fluid
Item
Clean funnel
■Brake fluid can absorb moisture
from the air
Excess moisture in the brake fluid
can cause a dangerous loss of brak-
ing efficiency. Use only newly
opened brake fluid.
NOTICE
■When adding coolant
Coolant is neither plain water nor
straight antifreeze. The correct
mixture of water and antifreeze
must be used to provide proper
lubrication, corrosion protection
and cooling. Be sure to read the
antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to
prevent it from d amaging parts or
paint.
Checking the radiator and
condenser
WARNING
■When the engine is hot
Do not touch the r adiator or con-
denser as they may be hot and
cause serious injuries, such as
burns.
■When the electric cooling fan
are operating
Do not touch the engine compart-
ment. With the engine switch in
ON, the electric cooling fan may
automatically start to run if the air
conditioning is on and/or the cool-
ant temperature is high. Be sure
the engine switch is OFF when
working near the electric cooling
fan or radiator grille.
Checking and adding the
brake fluid

3916-3. Do-it-yourself maintenance
6
Maintenance and care
Check the battery as follows.
■Battery exterior
Make sure that the battery termi-
nals are not corroded and that
there are no loose connections,
cracks, or loose clamps.
Terminals
Hold-down clamp
■Before recharging
When recharging, the battery pro-
duces hydrogen gas which is flam-
mable and explosive. Therefore,
observe the followi ng precautions
before recharging:
●If recharging with the battery
installed on the vehicle, be sure to
disconnect the ground cable.
●Make sure the power switch on
the charger is off when connecting
and disconnecting the charger
cables to the battery.
■After recharging/reconnecting
the battery
The engine may not start. Follow the
procedure below to initialize the sys-
tem.
1 Shift the shift lever to P.
2 Open and close any of the doors.
3 Restart the engine.
●Unlocking the doors using the
smart key system may not be pos-
sible immediately after reconnect-
ing the battery. If this happens,
use the wireless remote control or
the mechanical key to lock/unlock
the doors.
●Start the engine with the engine
switch in ACC. T he engine may
not start with th e engine switch
turned off. However, the engine
will operate normally from the sec-
ond attempt.
●The engine switch mode is
recorded by the vehicle. If the bat-
tery is disconnected and recon-
nected, the vehicle will return the
engine switch mode to the status it
was in before the battery was dis-
connected. Make sure to turn off
the engine before disconnecting
the battery. Take extra care when
connecting the battery if the
engine switch mode prior to the
battery being disconnected is
unknown.
If the system will not start even after
multiple attempts, contact your Toy-
WARNING
■When filling the reservoir
Take care as brake fluid can harm
your hands and eyes and damage
painted surfaces.
If fluid gets on your hands or in
your eyes, flush t he affected area
with clean water immediately.
If you still experien ce discomfort,
see a doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level
to go down slightly as the brake
pads wear out or when the fluid
level in the accumulator is high.
If the reservoir needs frequent
refilling, there may be a serious
problem.
Battery