2021 TOYOTA HIGHLANDER HYBRID ECU

4546-3. Do-it-yourself maintenance
HIGHLANDER HV_U
3Remove the light bulb.
4 Install a new light bulb, and
then install the bulb base to
the light unit by inserting it
and turning it clockwise.
After installing th e bulb base, wig-
gle it lightly to make sure it is
securely installed and turn on the
back-up lights to visually check that
there is no light leaking from
between the bulb base and light
unit.
5 Install the cover.
Align the tabs of the cover with the
grooves and install the cover.
■License plate lights
1 Remove the cover.
Using a flathead screwdriver,
remove the cover.
To prevent damage to the vehicle,
wrap the tip of th e flathead screw-
driver with tape, etc.
2 Remove the lens.
Lens
Hook

4566-3. Do-it-yourself maintenance
HIGHLANDER HV_U
WARNING
■To prevent injury
Before performing any light bulb
replacement procedure, be sure
to turn the power switch off. Fail-
ure to do so may result in burns
from hot compone nts or a part of
your body may get caught on an
operating component, possibly
causing serious injury.
■Replacing light bulbs
●Turn off the lights. Do not
attempt to replace the bulb
immediately after turning off the
lights.The bulbs become very
hot and may cause burns.
●Do not touch the glass portion
of the light bulb with bare
hands. When it is unavoidable
to hold the glass portion, use
and hold with a clean dry cloth
to avoid getting moisture and
oils on the bulb. Also, if the bulb
is scratched or dropped, it may
blow out or crack.
●Fully install light bulbs and any
parts used to secure them. Fail-
ure to do so may result in heat
damage, fire, or water entering
the light unit. This may damage
the lights or cause condensa-
tion to build up on the lens.
●Do not attempt t o repair or dis-
assemble light bulbs, connec-
tors, electric circuits or
component parts.
Doing so may result in death or
serious injury due to electric
shock.
■To prevent damage or fire
●Make sure bulbs are fully
seated and locked.
●Check the wattage of the bulb
before installing to prevent heat
damage.

4587-1. Essential information
HIGHLANDER HV_U
7-1.Essential information
Press the switch.
All the turn signal lights will flash.
To turn them off, press the switch
once again.
■Emergency flashers
●If the emergency flashers are
used for a long time while the
hybrid system is not operating
(while the “READY” indicator is
not illuminated), the 12-volt bat-
tery may discharge.
●If any of the SRS airbags deploy
(inflate) or in the event of a strong
rear impact, the emergency flash-
ers will turn on automatically.
The emergency flashers will turn
off automatically after operating
for approximately 20 minutes. To
manually turn t he emergency
flashers off, press the switch
twice.
(The emergency flashers may not
turn on automatically depending
on the force of the impact and
conditions of the collision.)
1 Steadily step on the brake
pedal with both feet and
firmly depress it.
Do not pump the brake pedal
repeatedly as this will increase the
effort required to slow the vehicle.
2Shift the shift lever to N.
If the shift lever is shifted to N
3 After slowing down, stop the
vehicle in a safe place by the
road.
4 Stop the hybrid system.
If the shift lever cannot be
shifted to N
3 Keep depressing the brake
pedal with both feet to reduce
vehicle speed as much as
possible.
4 To stop the hybrid system,
press and hold the power
switch for 2 consecutive sec-
onds or more, or press it
Emergency flashers
The emergency flashers are
used to warn other drivers
when the vehicle has to be
stopped on the road due to
a breakdown, etc.
Operating instructions
If your vehicle has to
be stopped in an emer-
gency
Only in an emergency, such
as if it becomes impossible
to stop the vehicle in the
normal way, stop the vehicle
using the following proce-
dure:
Stopping the vehicle

4627-2. Steps to take in an emergency
HIGHLANDER HV_U
The following may indicate a
problem with your transmission.
Contact your Toyota dealer or
commercial towing service
before towing.
The hybrid system warning
message is shown on the
multi-information display and
the vehicle does not move.
 The vehicle makes an abnor-
mal sound.
WARNING
■While towing
●When towing using cables or
chains, avoid sudden starts, etc.
which place excessive stress on
the towing eyelets, cables or
chains. The towing eyelets,
cables or chains may become
damaged, broken debris may hit
people, and cause serious dam-
age.
●Do not turn the power switch off.
There is a possibility that the
steering wheel is locked and
cannot be operated.
NOTICE
■To prevent damage to the
vehicle when towing using a
wheel-lift type truck
●Do not tow the vehicle from the
rear when the power switch is
off. The steering lock mecha-
nism is not strong enough to
hold the front wheels straight.
●When raising the vehicle,
ensure adequate ground clear-
ance for towing at the opposite
end of the raised vehicle. With-
out adequate clearance, the
vehicle could be damaged while
being towed.
■To prevent damage to the
vehicle when towing with a
sling-type truck
Do not tow with a sling-type truck,
either from the front or rear.
■To prevent damage to the
vehicle during emergency
towing
Do not secure cables or chains to
the suspension components.
■Recreational towing (behind
motor home, etc.)
Never dinghy tow your vehicle to
prevent causing serious damage
to the Hybrid AWD system (AWD
models) and transmission.
(  P.212)
Situations when it is nec-
essary to contact dealers
before towing

4737-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER HV_U
■Parking brake indicator (warning buzzer)*
*: A buzzer will sound if the vehicle is driven at a speed of app roximately 3
mph (5 km/h) or more.
■Brake hold operated indicator
■Warning buzzer
In some cases, the buzzer may not
be heard due to being in a noisy
location or audio sound.
■Front passenger detection sen-
sor, seat belt reminder and
warning buzzer
●If luggage is placed on the front
passenger seat, the front passen-
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 n ot 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 occupan
t classification
system (ECU and s ensors), “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 b elt pretensioner
and force limiter, airbags, intercon-
necting wiring and power sources.
(  P. 3 4 )
■If the malfunction indicator
lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel ta nk cap loose?
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, con tact your Toyota
Warning lightDetails/Actions
(flashes)
(U.S.A.)
or
(flashes)
(Canada)
It is possible that the parking brake is not fully engaged or
released
 Operate the parking brake switch once again.
This light comes on when the parking brake is not released.
If the light turns of f after the parking brake is fully release d,
the system is operating normally.
Warning lightDetails/Actions
(flashes)
Indicates a malfunction in the brake hold system
 Have the vehicle inspected by your Toyota dealer
immediately.

4927-2. Steps to take in an emergency
HIGHLANDER HV_U
WARNING
• VDIM
• Dynamic radar cruise control
with full-speed range
• PCS (Pre-Collision System)
• LTA (Lane Tracing Assist)
• RSA (Road Sign Assist) (if equipped)
• Automatic High Beam
• AFS (Adaptive Front-lighting System) (if equipped)
• Tire pressure warning system
• Intuitive parking assist (if equipped)
• PKSB (Parking Support Brake) (if equipped)
• Toyota parking assist monitor (if equipped)
• Panoramic view monitor (if equipped)
• BSM (Blind Spot Monitor)
• Navigation system (if equipped)
Also, not only can the following
system not be utilized fully, but it
may even negatively affect the
drive-train components:
• E-Four (AWD models)
■Speed limit when using the
compact spare tire
Do not drive at speeds in excess
of 50 mph (80 km/h) when a com-
pact spare tire is installed on the
vehicle.
The compact spare tire is not
designed for driving at high
speeds. Failure to observe this
precaution may lead to an acci-
dent causing death or serious
injury.
■After using the tools and jack
Before driving, ma ke sure all the
tools and jack are securely in
place in their storage location to
reduce the possibility of personal
injury during a collision or sudden
braking.
NOTICE
■Be careful when driving over
bumps with the compact
spare tire installed on the
vehicle
The vehicle becomes lower when
driving with the compact spare tire
compared to when driving with
standard tires. Be careful when
driving over uneven road sur-
faces.
■Driving with tire chains and
the compact spare tire
Do not fit tire chains to the com-
pact spare tire. Tire chains may
damage the vehicle body and
adversely affect d riving perfor-
mance.
■When replacing the tires
When removing or fitting the
wheels, tires or th e tire pressure
warning valve and transmitter,
contact your Toyota dealer as the
tire pressure warning valve and
transmitter may be damaged if not
handled correctly.
■When stowing the flat tire
●Ensure that there is no object
caught between the tire and the
vehicle underbody.

4937-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER HV_U
One of the following may be the
cause of the problem:
The electronic key may not be
functioning properly.
( P.496)
 There may not be sufficient
fuel in the vehicle’s tank.
Refuel the vehicle.
 There may be a malfunction
in the immobilizer system.
( P.79)
 There may be a malfunction
in the steering lock system.
 The hybrid system may be
malfunctioning due to an elec-
trical problem such as elec-
tronic key battery depletion or
a blown fuse. However,
depending on the type of mal-
function, an interim measure
is available to start the hybrid
system. ( P.494)
NOTICE
●Securely tighten the spare tire
clamp bolt to hold the spare
wheel carrier by the hook.
●Stow the flat tire in the spare tire
location. Failure to do so may
cause damage to the spare tire
carrier. Proper storage reduces
the possibility of injury in a colli-
sion or during sudden braking.
●Have the flat tire repaired and
the spare tire replaced with it as
soon as possible.
■Proper storage of the spare
tire
●If the hoist assembly is slanted
when stowing a tire, the hoist
assembly may become stuck in
the wheel opening and the tire
may not be raised properly,
causing damage to the wheel or
the wire cable.
●Do not attempt to turn the spare
tire clamp bolt without a tire on
the hoist assembly, as doing so
may cause the wire cable to slip
off of the shaft inside the unit
and the wire cable may not be
able to be raised or lowered. If
the spare tire clamp bolt has
been turned without a tire on the
hoist assembly and the wire
cable cannot be raised or low-
ered, contact your Toyota
dealer.
If the hybrid system
will not star t
Reasons for the hybrid sys-
tem not starting vary
depending on the situation.
Check the following and
perform the appropriate
procedure:
The hybrid system will not
start even though the cor-
rect starting procedure is
being followed. ( P.213)

5017-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER HV_U
■Starting the hybrid system
when the 12-volt battery is dis-
charged
The hybrid system cannot be started
by push-starting.
■To prevent 12-volt battery dis-
charge
●Turn off the headlights and the
audio system while the hybrid sys-
tem is off.
●Turn off any unnecessary electri-
cal components when the vehicle
is running at a low speed for an
extended period, such as in heavy
traffic.
■When the 12-volt battery is
removed or discharged
●Information stor ed in the ECU is
cleared. When the 12-volt battery
is depleted, have the vehicle
inspected at you r Toyota dealer.
●Some systems may require initial-
ization. ( P.542)
■When removing the 12-volt bat-
tery terminals
When the 12-volt battery terminals
are removed, the information stored
in the ECU is cleared. Before
removing the 12-volt battery termi-
nals, contact your Toyota dealer.
■Charging the 1 2-volt battery
The electricity stor ed in the 12-volt
battery will discharge gradually even
when the vehicle is not in use, due
to natural discharge and the drain-
ing effects of certain electrical appli-
ances. If the vehicle is left for a long
time, the 12-volt battery may dis-
charge, and the hybrid system may
be unable to start. (The 12-volt bat-
tery recharges aut omatically while
the hybrid system is operating.)
■When recharging or replacing
the 12-volt battery
●In some cases, i t may not be pos-
sible to unlock the doors using the
smart key system when the 12-volt battery is
discharged. Use
the wireless remote control or the
mechanical key to lock or unlock
the doors.
●The hybrid syste m may not start
on the first attempt after the
12-volt battery has recharged but
will start normally after the second
attempt. This is not a malfunction.
●The power switch mode is memo-
rized by the vehicle. When the
12-volt battery is reconnected, the
system will return to the mode it
was in before the 12-volt battery
was discharged. Before discon-
necting the 12-volt battery, turn
the power switch off.
If you are unsure what mode the
power switch was in before the
12-volt battery discharged, be
especially careful when recon-
necting the 12-volt battery.
●The power back door must be ini-
tialized. ( P.142)
■When replacing t he 12-volt bat-
tery
●Use a Central Degassing type
12-volt battery (European Regula-
tions).
●Use a 12-volt battery that the case
size is same as the previous one
(LN2), 20 hour rate capacity
(20HR) is equivalent (55Ah) or
greater, and per formance rating
(CCA) is equivalent (345A) or
greater.
• If the sizes differ, the 12-volt bat- tery cannot be properly secured.
• If the 20 hour rate capacity is low,
even if the time p eriod where the
vehicle is not used is a short time,
the 12-volt battery may discharge
and the hybrid system may not be
able to start.
●Use a 12-volt battery with a han-
dle. If a 12-volt battery without a
handle is used, removal is more
difficult.
●After replacing, firmly attach the
following items to the exhaust hole
of the 12-volt battery.