2020 MAZDA MODEL 3 HATCHBACK ECU

Fuses
▼Fuses
Your vehicle's electrical system is
protected by fuses.

If any lights, accessories, or controls do
not work, inspect the appropriate circuit
protector. If a fuse has blown, the inside
element will be melted.

If the same fuse blows
again, avoid using
that system and consult an Authorized
Mazda Dealer as soon as possible.
▼ Fuse Replacement
Replacing the fuses on the vehicle's left
side
If the electrical system does not work, first
inspect the fuses on the vehicle's left side.

1. Make sure the ignition is switched off,
and other switches are off.
2. Open the fuse panel cover.
3. Pull the fuse straight out with the fuse puller provided on the fuse block
located in the engine compartment.
4. Inspect the fuse and replace it if it is
blown.
1. Normal
2. Blown

5. Insert a new fuse of the same amperage rating, and make sure it fits
tightly. If it does not fit tightly, have an
expert install it. Consult an Authorized
Mazda Dealer.
If you have no spare fuses, borrow one
of the same rating from a circuit not
essential to vehicle operation, such as
the audio or accessory socket circuit.
CAUTION
Always replace a fuse with a genuine
Mazda fuse or equivalent of the same
rating. Otherwise you may damage the
electric system.
6. Reinstall the cover and make sure that it is securely installed.
Maintenance and Care
Owner Maintenance
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Replacing the fuses under the hood
If the headlights or other electrical
components do not work and the fuses in
the cabin are normal, inspect the fuse
block under the hood.
If a fuse is blown, it must be replaced.
Follow these steps:

1. Make sure the ignition is switched off,
and other switches are off.
2. Remove the fuse block cover.
3. If any fuse but the MAIN fuse is
blown, replace it with a new one of the
same amperage rating .
1. Normal
2. Blown

WA R N I N G
Do not replace the main fuse by
yourself. Have an Authorized Mazda
Dealer perform the replacement:
Replacing the fuse by yourself is
dangerous because the MAIN fuse is a
high current fuse. Incorrect
replacement could cause an electrical
shock or a short circuit resulting in a
fire.
4. Reinstall the cover and make sure that it is securely installed.
Maintenance and Care
Owner Maintenance
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▼Active Driving Display
Maintenance*
The dust-proof sheet has a coating. When
cleaning, do not use a hard or
rough-surface cloth, or cleaning detergent.
In addition, if a chemical solvent gets on
the active driving display, wipe it off
immediately. The dust-proof sheet could
be damaged and the surface coating could
be scratched. Use a fine, soft cloth such as
those used for cleaning eyeglasses.
NOTE
Use of compressed air when cleaning the
dust-proof sheet is recommended.
▼Panel Maintenance
If a panel becomes soiled, wipe it off with
a soft cloth soaked in clean water and
thoroughly wrung out.
If some areas require further cleaning, use
the following procedure:
1. Wipe the soiled area with a soft cloth
soaked in a mild detergent (approx.
5 %) diluted with water.
2. Wipe off the remaining detergent using a cloth soaked in clean water and
wrung out well.
NOTE
Be particularly careful when cleaning
shiny surface panels and metallic parts
such as plating as they can be scratched
easily.
▼Cleaning the Window Interiors
If the windows become covered with an
oily, greasy, or waxy film, clean them with
glass cleaner. Follow
the directions on the
container.
CAUTION
 Do not scrape or scratch the inside of the
window glass. It could damage the
thermal filaments and the antenna lines.
 When washing the inside of the window
glass, use a soft cloth dampened in
lukewarm water, gently wiping the
thermal filaments and the antenna lines.
Use of glass cleaning products could
damage the thermal filaments and the
antenna lines.
▼ Cleaning the Floor Mats
Rubber floor mats should be cleaned with
mild soap and water only.
WA R N I N G
Do not use rubber cleaners, such as tire
cleaner or tire shine, when cleaning rubber
floor mats:
Cleaning the rubber floor mats with rubber
cleaning products makes the
floor mats
slippery.
This may cause an accident when
depressing the accelerator, brake, or clutch
(Manual transmission) pedal or when
getting in or out of the vehicle.
After removing the floor mats for
cleaning, always reinstall them securely
(page 3-46).
Maintenance and Care
Appearance Care
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2. Remove the cover.
3. Turn the wing bolt and jack screwcounterclockwise.

1. Wing bolt
2. jack screw

5–Door
1. Remove the luggage mat.
2. Remove the jack.
To secure the jack
4–Door
1. Insert the wing bo lt into the jack with
the jack screw pointing to the front and
turn the wing bolt clockwise to
temporarily tighten it.
2. Turn the jack screw clockwise.
1. Wing bolt
2. jack screw

3. Turn the wing bolt completely to secure the jack.
NOTE
If the jack is not comp letely secured, it
could rattle while driving. Make sure the
jack screw is sufficiently tightened.
If Trouble Arises
Flat Tire
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(Vehicles without sub-woofer)
Turn the spare tire hold-down bolt
counterclockwise and remove the spare
tire.

1. Spare tire hold-down bolt
NOTE
If the spare tire hold-down bolt cannot
be loosened, hold the edge of the tire
and turn the spare tire hold-down bolt
until it rotates.
To secure the spare tire
Store the spare tire in the reverse order of
removal. After storing, verify that the
spare tire is stored securely.
Changing a Flat Tire
▼ Changing a Flat Tire
NOTE
If the following occurs while driving, it
could indicate a flat tire.
Steering becomes difficult.
The vehicle begins to vibrate
excessively.
The vehicle pulls in one direction.
If you have a flat ti re, drive slowly to a
level spot that is well off the road and out
of the way of traffic to change the tire.
Stopping in traffic or on the shoulder of a
busy road is dangerous.
WA R N I N G
Be sure to follow the directions for
changing a tire:
Changing a tire is dangerous if not done
properly. The vehicle can slip off the jack
and seriously injure someone.
No person should place any portion of their
body under a vehicle that is supported by a
jack.
Never allow anyone inside a vehicle
supported by a jack:
Allowing someone to remain in a vehicle
supported by a jack is dangerous. The
occupant could cause the vehicle to fall
resulting in serious injury.
NOTE
Make sure the jack is well lubricated
before using it.
If Trouble Arises
Flat Tire
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WA R N I N G
Do not apply oil or grease to lug nuts
and bolts and do not tighten the lug
nuts beyond the recommended
tightening torque:
Applying oil or grease to lug nuts and
bolts is dangerous. The lug nuts could
loosen while driving and cause the tire
to come off, resulting in an accident. In
addition, lug nuts and bolts could be
damaged if tightened more than
necessary.
4. Turn the jack handle counterclockwise using the lug wrench and lower the
vehicle.
5. Use the lug wrench to tighten the nuts in the order shown.

If you are unsure of how tight the nuts
should be, have them inspected at an
Authorized Mazda Dealer.
Nut tightening torque
N·m (kgf·m, ft·lbf) 108―147 (12―14,
80―108)
WA R N I N G
Always securely and correctly tighten
the lug nuts:
Improperly or loosely tightened lug
nuts are dangerous. The wheel could
wobble or come off. This could result in
loss of vehicle control and cause a
serious accident.
Be sure to reinstall the same nuts you
removed or replace them with metric
nuts of the same configuration:
Because the wheel studs and lug nuts
on your Mazda have metric threads,
using a non-metric nut is dangerous.
On a metric stud, it would not secure
the wheel and would damage the stud,
which could cause the wheel to slip off
and cause an accident.
6. (Aluminum wheel equipped vehicle)
Remove the center cap by tapping it
from the backside of the wheel using
the lug wrench.
7. Store the damaged tire in the trunk (4-door) or lugg age compartment
(5-door).

8. Secure the damaged tire to the vehicle using the following method.
If Trouble Arises
Flat Tire
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(Vehicles with flat tire hold-down
bolt (excluding vehicles with
sub-woofer for 5-door))
1. Spread apart the tabs on the sparetire hold-down bolt that was
removed when removing the spare
tire and remove the bolt for
securing the spare tire.
1. Tabs
2. Bolt for securing spare tire
3. Spare tire hold-down bolt

2. Remove the bolt for securing the
flat tire from its stored position and
install it in place of the removed
spare tire hold-down bolt.
1. Bolt for securing the flat tire
2. Spare tire hold-down bolt

NOTE
The longer bolt is used as the bolt
for securing the flat tire, and the
shorter one is used as the bolt for
securing the spare tire. When
installing a bolt, check the bolt's
length.
3. Secure the damaged tire to the vehicle using the flat tire
hold-down bolt.
(Vehicles with flat tire hold-down
bolt and with sub-woofer for
5-door))
1. Remove the bolt for securing theflat tire from its stored position.
2. Secure the damaged tire to the vehicle using the flat tire
hold-down bolt.
1. Flat tire hold-down bolt
2. Sub-woofer

If Trouble Arises
Flat Tire
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(Vehicles without flat tire hold-down
bolt)
1. Secure the damaged tire to thevehicle using the spare tire
hold-down bolt removed when
removing the spare tire.
9. Place the trunk mat (4-door) orluggage mat (5-door) on the damaged
tire.
10. Remove the tire blocks and store thetools and jack.
11. Check the inflation pressure. Refer to Tires on page 9-9.
12. Have the flat tire repaired or replaced
as soon as possible.
13. After repairing or replacing the flat
tire, install the wheel cover (vehicles
with steel wheels) or center cap
(vehicles with alumi num wheels) using
the following procedure.
(Wheel cover)
1. Align the notch on the wheel cover with the tire valve of the wheel and
install the whee l cover to the
wheel.
1. Notch
2. Tire valve
CAUTION
Always align the notch on the wheel
cover with the tire valve of the
wheel. Otherwise, it could cause
damage to the wheel cover and the
tire valve.
(Center cap)
1. Align the center cap with the center hole of the wheel and install the
center cap to the wheel.
If Trouble Arises
Flat Tire
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