ECU MAZDA MODEL 3 HATCHBACK 2021 Owner's Manual

Never attach two child-restraint
systems to the same ISOFIX/LATCH*1
lower anchor:
Attaching two child-restraint systems
to the same ISOFIX/LATCH
*1 lower
anchor is dangerous. In a collision, one
anchor may not be strong enough to
hold two child-restraint system
attachments, and it may break, causing
serious injury or death. If you use the
seat position for another child-restraint
system when an outboard ISOFIX/
LATCH
*1 position is occupied, use the
center seat belts instead, and the
tether if tether-equipped.
Make sure the child-restraint system is
properly secured:
An unsecured child-restraint system is
dangerous. In a sudden stop or a
collision it could move causing serious
injury or death to the child or other
occupants. Follow the child-restraint
system manufacturer's instructions on
belt routing to secure the seat just as
you would with a child in it so that
nobody is tempted to put a child in an
improperly secured seat later on.
When not in use, remove it from the
vehicle or fasten it with a seat belt, or
attach it to BOTH ISOFIX/LATCH
*1
lower anchors for ISOFIX/LATCH*1
child-restraint systems.
Make sure there are no seat belts or
foreign objects near or around the
ISOFIX/LATCH
*1 child-restraint
system:
Not following the child-restraint system
manufacturer's instructions when
installing the child-restraint system is
dangerous. If seat belts or a foreign
object prevent the child-restraint
system from being securely attached to
the ISOFIX/LATCH
*1 lower anchors
and the child-restraint system is
installed improperly, the child-restraint
system could move in a sudden stop or
collision causing serious injury or death
to the child or other occupants. When
installing the child-restraint system,
make sure there are no seat belts or
foreign objects near or around the
ISOFIX/LATCH
*1 lower anchors.
Always follow the child-restraint
system manufacturer's instructions.
*1ISOFIX (Mexico)/LATCH (Except Mexico)
Installation on rear outboard seats
1. First, adjust the front seat to allow clearance between the
child-restraint system and the front
seat.
Refer to Adjusting the Driver's Seat
on page 2-5.
Refer to Adjusting the Front
Passenger's Seat on page 2-13.
2. Make sure the seatback is securely latched by pushing it back until it is
fully locked.
Essential Safety Equipment
Child Restraint
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3. Remove the cover of thechild-restraint system's ISOFIX/
LATCH
*1 lower anchors to verify the
locations of the ISOFIX/LATCH*1
lower anchors.
1. Lower anchor

NOTE
The ISOFIX/LATCH*1 lower
anchors marking on the cover
indicates the position of the
ISOFIX/LATCH
*1 lower anchors
for the attachment of a
child-restraint system.
Store the removed cover so that it
does not get lost.
4. Remove the head restraint.
However, when installing a backless
booster seat, always install the
vehicle head restraint to the seat
where the backless booster seat is
installed.
Refer to Head Restraints on page
2-17.
5. Secure the child-restraint system
using BOTH ISOFIX/LATCH
*1 lower
anchors, following the
child-restraint system
manufacturer's instruction. Pull on
the child-restraint to be sure both
anchors are engaged.
6. If your child-restraint system came equipped with a tether, that means
it is very important to properly
secure the tether for child safety.
Please carefully follow the
child-restraint system
manufacturer's instructions when
installing tethers.
*1 ISOFIX (Mexico)/LATCH (ExceptMexico)
WARNING
Use the tether and tether anchor only
for a child-restraint system:
Using the tether or tether anchor to
secure anything but a child-restraint
system is dangerous. This could
weaken or damage the tether or tether
anchor and result in injury.
Always remove the head restraint and
install child-restraint system (except
when installing a backless booster
seat):
Installing a child-restraint system
without removing the head restraint is
dangerous. The child-restraint system
cannot be installed correctly which
may result in death or injury to the
child in a collision.
(4–Door)
1. Tether strap
Essential Safety Equipment
Child Restraint
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If your vehicle is also equipped with a
front passenger occupant
classification system, refer to the Front
Passenger Occupant Classi fication
System (page 2-70) for details.
If your vehicle is equipped with a front
passenger occupant classi fication
system, the front passenger air bag
deactivation indicator light illuminates
for a speci fied time after the ignition is
switched ON.


Small children must be protected by a
child-restraint system as stipulated by
law in every state and province. In
certain states and provinces, larger
children must use a child-restraint
system (page 2-32).

Carefully consider which child-restraint
system is necessary for your child and
follow the installation directions in this
Owner's Manual as well as the
child-restraint system manufacturer's
instructions.
WARNING
Seat belts must be worn in air bag
equipped vehicles:
Depending only on the air bags for
protection during an accident is
dangerous. Alone, air bags may not
prevent serious injuries. The
appropriate air bags can be expected
to in flate only in the first accident, such
as frontal, near frontal or side collisions
or roll-over accidents that are at least
moderate. Vehicle occupants should
always wear seat belts.

Children should not ride in the front
passenger seat:
Placing a child, 12 years or under, in
the front seat is dangerous. The child
could be hit by a deploying air bag and
be seriously injured or even killed. A
sleeping child is more likely to lean
against the door and be hit by the side
air bag in moderate collision to the
front-passenger side of the vehicle.
Whenever possible, always secure a
child 12 years and under on the rear
seats with an appropriate
child-restraint system for the child's
age and size.
Essential Safety Equipment
SRS Air Bags
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A rear passenger steps on the front
passenger seat rails with their feet.
 Luggage or other items are placed on
the seatback or hung on the head
restraint.
 Heavy items are placed in the
seatback map pocket.
 The seat is washed.
 Liquids are spilled on the seat.
 The front passenger seat is moved
backward, pushing into luggage or
other items placed behind it.
 The front passenger seatback
contacts the rear seat.
 Luggage or other items are placed
between the front passenger seat
and driver seat.
 Any accessories which might increase
the total seated weight on the front
passenger seat are attached to the
front passenger seat.
CAUTION
To assure proper deployment of the
front air bag and to prevent damage
to the sensors in the front seat
bottoms:
 Do not place sharp objects on the
front seat bottoms or leave heavy
luggage on them.
 Do not spill any liquids on the
front seats or under the front seats.
 To allow the sensors to function
properly, always perform the
following:
 Adjust the front seats as far back as
possible and always sit upright
against the seatbacks with seat
belts worn properly.
If you place your child on the front
passenger seat, secure the
child-restraint system properly and
slide the front passenger seat as far
back as possible (page 2-47).
NOTE
The system requires about 10
seconds to alternate between turning
the front passenger front and side air
bags and knee air bags, and seat belt
pretensioner system on or o ff.
The front passenger air bag
deactivation indicator light may
illuminate repeatedly if luggage or
other items are put on the front
passenger seat, or if the temperature
of the vehicle's interior changes
suddenly.
The front passenger air bag
deactivation indicator light may
illuminate for 10 seconds if the total
seated weight on the front passenger
seat changes.
The air bag/front seat belt
pretensioner system warning light
might illuminate if the front
passenger seat receives a severe
impact.
If the front passenger air bag
deactivation indicator light does not
illuminate after installing a
child-restraint system on the front
passenger seat,
first, re-install your
child-restraint system according to
the procedure in this owner's
manual. Then, if the front passenger
air bag deactivation indicator light
still does not illuminate, install the
child-restraint system on the rear seat
and consult an Authorized Mazda
Dealer as soon as possible.
Essential Safety Equipment
SRS Air Bags
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If the front passenger air bag
deactivation indicator light
illuminates when an adult is seated
in the front passenger seat, have the
passenger re-adjust their posture by
sitting with their feet on the floor,
and then re-fastening the seat belt. If
the front passenger air bag
deactivation indicator light still
illuminates, move the passenger to
the rear seat. If sitting in the rear seat
is not possible, slide the front
passenger seat as far back as
possible. Consult an Authorized
Mazda Dealer as soon as possible.
▼ Driver and Front Passenger Buckle
Switches
The buckle switches on the front seat
belts detect whether or not the front
seat belts are securely fastened and
further control the deployment of the
air bags.
Constant Monitoring
▼Constant Monitoring
The following components of the air
bag systems are monitored by a
diagnostic system:

Front air bag sensorsCrash sensors, and diagnostic
module (SAS unit)
Side crash sensorsAir bag modulesFront seat belt pretensionersAir bag/Front seat belt pretensioner
system warning light
Related wiring
(With Driver and Front Passenger
Occupant Classification System)
Driver seat slide position sensorFront passenger occupant
classi fication sensor
Front passenger occupant
classi fication module
Front passenger air bag deactivation
indicator light
Front passenger seat belt buckle
switch

The diagnostic module continuously
monitors the system's readiness. This
begins when the ignition is switched
ON and continues while the vehicle is
being driven.
Essential Safety Equipment
SRS Air Bags
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3Before Driving
Use of various features, including keys, doors, mirrors and
windows.
Keys........................................ 3-2 Keys...................................... 3-2
Keyless Entry System...............3-4
Advanced Keyless Entry
System.....................................3-9 Advanced Keyless Entry
System
*................................. 3-9
Operational Range...............3-10
Doors and Locks..................... 3-11 Door Locks.......................... 3-11
Liftgate/Trunk Lid.................3-19
Inside Trunk Release Lever (4-
door)
*................................. 3-24
Fuel and Emission................... 3-25 Fuel and Engine Exhaust
Precautions......................... 3-25
Fuel-Filler Lid and Cap..........3-27
Mirrors.................................. 3-30 Mirrors................................3-30
Windows............................... 3-34 Power Windows...................3-34
Moonroof*.......................... 3-37
Security System.......................3-40 Modi fication and Add-
On Equipment..................... 3-40
Immobilizer System..............3-40
Theft-Deterrent System
*........3-42
Driving Tips............................ 3-44 Break-In Period.................... 3-44
Saving Fuel and Protection of the
Environment........................ 3-44
Hazardous Driving............... 3-45
Floor Mat............................ 3-46
Rocking the Vehicle..............3-46
Winter Driving..................... 3-47
Driving In Flooded Area........3-49
Overloading........................ 3-49
Driving on Uneven Road.......3-50
Turbocharger Information
(SKYACTIV -G 2.5T).............. 3-50
Towing.................................. 3-51 Trailer Towing...................... 3-51
Recreational Towing............. 3-51
*Some models.3-1
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Door Locks
▼Door Locks
WARNING
Always take all children and pets with
you or leave a responsible person
with them:
Leaving a child or a pet unattended in
a parked vehicle is dangerous. In hot
weather, temperatures inside a vehicle
can become high enough to cause
brain damage or even death.
Do not leave the key in your vehicle
with children and keep them in a
place where your children will not
fi
nd or play with them:
Leaving children in a vehicle with the
key is dangerous. This could result in
someone being badly injured or even
killed.
Keep all doors locked when driving:
Unlocked doors in a moving vehicle
are dangerous. Passengers can fall out
if a door is accidentally opened and
can more easily be thrown out in an
accident.
Always close all the windows and
moonroof, lock the doors, fuel-filler
lid, and liftgate and take the key with
you when leaving your vehicle
unattended:
Leaving your vehicle unlocked is
dangerous as children could lock
themselves in a hot vehicle, which
could result in death. Also, a vehicle
left unlocked becomes an easy target
for thieves and intruders.
After closing the doors and the
liftgate/trunk lid, always verify that
they are securely closed:
Doors and the liftgate/trunk lid not
securely closed are dangerous, if the
vehicle is driven with a door and the
liftgate/trunk lid not securely closed,
the door and the liftgate/trunk lid
could open unexpectedly resulting in
an accident.
Always con firm the safety around the
vehicle before opening a door and the
liftgate/trunk lid:
Suddenly opening a door and the
liftgate/trunk lid is dangerous. A
passing vehicle or a pedestrian could
be hit and cause an accident.
CAUTION
 Always
confirm the conditions
around the vehicle before opening/
closing the doors and the liftgate/
trunk lid and use caution during
strong winds or when parked on an
incline. Not being aware of the
conditions around the vehicle is
dangerous because fingers could get
caught in the door and the liftgate/
trunk lid or a passing pedestrian
could be hit, resulting in an
unexpected accident or injury.
Before Driving
Doors and Locks
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▼Unlocking with Auxiliary Key
Only the driver's door can be unlocked
using the auxiliary key.
Refer to Keys on page 3-2.
Insert the auxiliary key while the
driver's door handle is pulled and turn
the key to the unlock side. Turn the
auxiliary key back to its original
position before removing it.
NOTE
If you attempt to open the driver’s
door using an unauthorized auxiliary
key, the key cylinder will spin around
but the door will not unlock.
▼Locking , Unlocking with Touch
Sensor, Door Handle (With the
advanced keyless function)
By touching the sensing area of the
touch sensor, various locking/
unlocking operations can be done
without taking the key out of a bag or
pocket.
There are two types of touch sensors
used for locking and unlocking, and
each sensor is built into the outer door
handle on the driver and front
passenger's doors.
1. Sensing area of door lock touch
sensor (Depression on outer side of
door handle)
2. Sensing area of door release touch
sensor (Inner side of door handle)
NOTE
When locking/unlocking with the
transmitter carried, securely touch
the sensing area of the touch sensor
as follows.
Locking
Unlocking
The system may not operate normally
under the following conditions.
You touch the sensing area of the
door lock touch sensor and the
sensing area of the door release
touch sensor at the same time.
You touch the sensing area of the
touch sensor whil e wearing gloves.
Foreign matter such as snow or dirt
is stuck on the sensing area of the
touch sensor.
Before Driving
Doors and Locks
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You pull the door handle just after
touching the sensing area of the
touch sensor.
The system may operate if the outer
side door handle of a front door is
splashed with water by a car wash or
rain while the transmitter is in the
operation range.
If the system does not operate even
though you touch the sensing area of
the touch sensor correctly, release
the touch sensor once, and then
touch the sensing area of the touch
sensor again after waiting about 3
seconds.
Locking
When locking, touch the sensing area
of the door lock touch sensor with all
of the following conditions met.
The ignition is switched OFF.All the doors are closed.You are carrying the transmitter.
The following locations are locked by
touching the sensing area of the door
lock touch sensor.
All doorsFuel- filler lidLiftgate
When locking, the hazard warning
lights and sound operate one time.
Unlocking
When unlocking, touch the sensing
area of the door release touch sensor
with all of the following conditions
met.
The ignition is switched OFF.The driver’s door is locked.Three seconds or longer have passed
since the doors were locked.
You are carrying the transmitter.
(Unlocking from the driver's door)
The following locations are unlocked
by touching the sensing area of the
door release touch sensor of the
driver's door.
Driver’s doorFuel- filler lid
NOTE
The location to be unlocked can be
changed.
Refer to the Settings section in the
Mazda Connect Owner's Manual.
When unlocking , the hazard warning
lights and sound operate two times.

(Unlocking from the front passenger’s
door)
The following locations are unlocked
by touching the sensing area of the
door release touch sensor of the front
passenger's door.
All doorsFuel- filler lidLiftgate
When unlocking , the hazard warning
lights and sound operate two times.
NOTE
Con firm that all the doors and
liftgate/trunk lid are securely locked.
For the liftgate/trunk lid, move it
without pressing the electric liftgate/
trunk lid opener to verify that the
liftgate/trunk lid has not been left
ajar.
Before Driving
Doors and Locks
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▼Rear Door Child Safety Locks
Rear doors that have been locked
using the child safety lock switched to
the lock side cannot be opened from
inside the vehicle.
For child safety, switch the child safety
lock on both rear doors to the lock
side.
When opening a rear door with the
child safety lock switched to the lock
side, pull the outer door handle with
the lock knob inside the vehicle
switched to the unlock side.
1. Auxiliary key (page 3-2)
2. Lock
3. Unlock
Liftgate/Trunk Lid
▼Liftgate/Trunk Lid
WARNING
Never allow a person to ride in the
luggage compartment/trunk:
Allowing a person to ride in the
luggage compartment/trunk is
dangerous. The person in the luggage
compartment/trunk could be seriously
injured or killed during sudden braking
or a collision.
Do not drive with the liftgate/trunk
lid open:
Exhaust gas in the cabin of a vehicle is
dangerous. An open liftgate/trunk lid
in a moving vehicle will cause exhaust
gas to be drawn into the cabin. This
gas contains CO (carbon monoxide),
which is colorless, odorless, and highly
poisonous, and it can cause loss of
consciousness and death. Moreover,
an open liftgate/trunk lid could cause
occupants to fall out in an accident.
Do not stack or leave loaded luggage
unsecured in the luggage
compartment:
Otherwise, the luggage may move or
collapse, resulting in injury or an
accident. In addition, do not load
luggage higher than the seatbacks. It
may a
ffect the side or rear field of view.
Additionally, if the air bags deploy, the
cargo may scatter which could result in
serious injury or death.
Before Driving
Doors and Locks
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