2021 MAZDA MODEL 3 HATCHBACK brake sensor

To assure the correct operation of the
SBS-RC, heed the following cautions.
 Do not apply a sticker to a rear radar
and rear camera. Otherwise, the rear
radar and rear camera may not be
able to detect vehicles or
obstructions which could result in an
accident.
 Do not disassemble a rear radar and
rear camera.
 If cracks or damage caused by flying
gravel or debris is visible around a
rear radar and rear camera, stop
using the SBS -RC system
immediately and have your vehicle
inspected by an Authorized Mazda
Dealer. If the vehicle continues to be
driven with cracks or scratch marks
left around an ultrasonic sensor, the
system may operate unnecessarily
and cause an unexpected accident.
Refer to Stopping the Smart Brake
Support [Rear Crossing] (SBS -RC)
System Operation on page 4-168.
 Consult an Authorized Mazda Dealer
for rear bumper removal.
Do not modify the suspension:
If the vehicle height or inclination is
changed, the SBS -RC system may not
operate correctly because it cannot
detect obstructions correctly.Do not apply a strong force to a rear
radar and rear camera:
When washing the vehicle, do not
spray highly pressurized water against a
rear radar and rear camera, or rub it
strongly. In addition, do not hit the rear
bumper forcefully when loading and
unloading cargo. Otherwise, the
sensors may not detect obstructions
correctly which could cause the
SBS -RC system to not operate
normally, or it could operate
unnecessarily.
NOTE
The SBS -RC system will operate
under the following conditions.
The engine is running for 3 seconds
or more.
The shift lever (manual
transmission ve hicle) or the
selector lever (automatic
transmission vehicl e) is in the R
(reverse) position.
i-ACTIVSENSE warning indication/
warning light is not displayed in the
multi-information display.
The vehicle speed is under about
10 km/h (6 mph).
The vehicle speed of an
approaching vehicle is about 3
km/h (2 mph) or faster.
The SBS-R is not turned
off.The DSC is not malfunctioning.In the following cases, the
i-ACTIVSENSE warning indication/
warning light turns on and operation
of the system is stopped. If the
i-ACTIVSENSE warning indication/
warning light remains illuminated,
have the vehicle inspected at an
Authorized Mazda Dealer as soon as
possible.
Some problem with the system
including the SBS -RC system.
When Driving
i-ACTIVSENSE
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A pedestrian is in a dark location
such as during the night, or blends
into the background by wearing
clothes matching the background
color.Front Radar Sensor*
▼Front Radar Sensor
Your vehicle is equipped with a front
radar sensor.
The following systems also use the
front radar sensor.
Distance & Speed Alert (DSA)Mazda Radar Cruise Control
(MRCC)
Mazda Radar Cruise Control with
Stop & Go function (MRCC with
Stop & Go function)
Tra
ffic Jam Assist (TJA)Smart Brake Support (SBS)
The front radar sensor functions by
detecting the radio waves re flected o ff
a vehicle ahead or an obstruction sent
from the radar sensor.
The front radar sensor is mounted
behind the front emblem.
1. Front radar sensor

If “Safety and Driver Support Systems
Temporarily Disabled. Front Radar
Obscured. Drive Safely” is displayed on
the multi-information display of the
instrument cluster, clean the area
around the front radar sensor.
CAUTION
Heed the following precautions to
assure correct operation of each
system.
When Driving
i-ACTIVSENSE
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Rear Side Radar Sensor*
▼Rear Side Radar Sensor
Your vehicle is equipped with rear side
radar sensor. The following systems
also use the rear side radar sensor.
Blind Spot Monitoring (BSM)Rear Cross Tra
ffic Alert (RCTA)Smart Brake Support [Rear Crossing]
(SBS -RC)
The rear side radar sensors emit radio
waves and detect the radio waves
re flected off a vehicle approaching
from the rear or an obstruction.
4–Door
1. Rear side radar sensor

5–Door
1. Rear side radar sensor

The rear side radar sensors are installed
inside the rear bumper, one on each
side.
Always keep the surface of the rear
bumper near the rear side radar
sensors clean so that they operate
normally. Also, do not apply items such
as stickers.
Refer to Exterior Care on page 6-48.
CAUTION
If the rear bumper receives a severe
impact, the system may no longer
operate normally. Stop the system
immediately and have the vehicle
inspected at an Authorized Mazda
Dealer.
NOTE
The detection ability of the rear side
radar sensor has limitations. In the
following cases, the detection ability
may lower and the system may not
operate normally.
The rear bumper near the rear side
radar sensor has become
deformed.
Snow, ice or mud adheres to the
rear side radar sensor on the rear
bumper.
Under bad weather conditions
such as rain, snow and fog.
Under the following conditions, the
rear side radar sensor cannot detect
target objects or it may be di fficult to
detect them.
Small motorcycles, bicycles,
pedestrians, animals, shopping
carts, and stationary objects on a
road or a road side.
Vehicle shapes which do not re flect radar waves well such as
empty trailers with a low vehicle
height and sports cars.
When Driving
i-ACTIVSENSE
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CAUTION
Do not install any accessories within the detection ranges of the sensors. It may
a ff ect the system operation.
 Depending on the type of obstruction and the surrounding conditions, the
detection range of a sensor may narrow, or the sensors may not be able to detect
obstructions.
NOTE
When the ignition is switched OFF, the system status before it was turned off is
maintained. For example, if the ignition is switched OFF while the parking sensor
is activated, the system will be activate d when the ignition is switched ON the
next time.
The system may not operate normally under the following conditions:
Mud, ice, or snow is adhering to the sensor area (Returns to normal operation
when removed).
The sensor area is frozen (Returns to normal operation when the ice is thawed).The sensor is covered by a hand.The sensor is excessively shocked.The vehicle is excessively tilted.Under extremely hot or cold weather conditions.The vehicle is driven on bumps, inclines, gravel, grating, or grass covered roads.Anything which generates ultrasonic wave s such as another vehicle's horn, the
engine sound of a motorcycle, the air brake sound of a large-sized vehicle, or
another vehicle's sensors approaches the vehicle.
The vehicle is driven in heavy rain or in road conditions causing water-splash.A commercially-available fender pole or an antenna for a radio transmitter is
installed to the vehicle.
The vehicle is moving towards a tall or square curbstone, or a steep grade.An obstruction is too close to the sensor.The vehicle is moving towards an uneven wall or stairs.There are multiple obstructions.The vehicle is driven in a place with low ceilings.Obstructions under the bumper cannot be detected. Obstructions which are
lower than the sensor or thin may not be detected even though they were
detected once.
The following types of obstructions may not be detected:
Thin objects such as wire, rope or polesThings which absorb sonic waves easily such as cotton or snowAngular shaped objectsVery tall objects, and those which are wide at the topSmall, short objectsAlways have the system inspected at an Authorized Mazda Dealer if any shock is
applied to the bumpers, even in a minor accident. If the sensors are deviated, they
cannot detect obstructions.
When Driving
Pa r k i n g S e n s o r Sys te m
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DisplayDistance between vehicle and obstruc-
tion
Without 360° view monitor
With 360° viewmonitor Front ultrasonic
sensor
*/Front cor-
ner ultrasonic sen-
sor
*
Rear ultrasonic sen-sor/Rear corner ul- trasonic sensor/
Rear side ultrasonic
sensor
*
Without front ul-trasonic sensor
and front corner
ultrasonic sensor With front ultra-
sonic sensor and
front corner ultra-
sonic sensor
RedFront ultrasonic sen-
sor:
Within approx. 35.0
cm (13.7 in)
Front corner ultra- sonic sensor:
Within approx. 25 cm (9.8 in) Rear ultrasonic sen-
sor:
Within approx. 35.0 cm (13.7 in)
Rear corner ultra-
sonic sensor/Rear
side ultrasonic sen-
sor:
Within approx. 25
cm (9.8 in)
▼Parking Sensor OFF Switch
When the switch is pressed, the
parking sensor is stopped and the
indicator light turns on.
If the switch is pressed again, the
parking sensor becomes operational
and the indicator light turns o
ff.
1. Indicator light
NOTE
(Automatic vehicle)
The detection indicator and buzzer
of the front ultrasonic sensors/front
corner ultrasonic sensors do not
operate when the selector lever is in
the P position.
The detection indicator and buzzer
sound do not activate when the
parking brake is applied.
When Driving
Pa r k i n g S e n s o r Sys te m
4-242*Some models.
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▼Tire Pressure Monitoring System
(TPMS) Warning Indication/
Warning Light (Flashing)
If there is a problem with the TPMS or
the voltage of a tire pressure sensor
decreases, the TPMS warning light
fl
ashes and a message is displayed on
the multi-information display. Have
your vehicle inspected by an
Authorized Mazda Dealer.
WARNING
Do not drive the vehicle at high
speeds if the TPMS warning light turns
on or fl ashes:
Driving the vehicle at high speeds
while the TPMS warning light is turned
on or fl ashing is dangerous because
the brake performance and the
steering wheel operability will be
reduced. If the vehicle is driven at high
speeds or the brakes are suddenly
applied, it could lead to an accident.
Gradually apply the brakes to lower the
vehicle's speed.
Do not ignore the TPMS warning light
when it is turned on or flashing:
Continuing to drive the vehicle while
ignoring the illumination/ flashing of
the TPMS warning light is dangerous
because a tire may burst which could
lead to an accident. Take appropriate
measures as soon as possible.
▼ KEY Warning Indication/Warning
Light (Red)
“Keyless Entry System Malfunction.
Have the Vehicle Inspected” is
displayed
This message is displayed if the
advanced keyless entry & push button
start system has a problem.
Contact an Authorized Mazda Dealer.
CAUTION
If the message is indicated, or the push
button start indicator light (amber)
fl
ashes, the engine may not start. If the
engine cannot be started, try starting it
using the emergency operation for
starting the engine, and have the
vehicle inspected at an Authorized
Mazda Dealer as soon as possible.
Refer to Emergency Operation for
Starting the Engine on page 4-9.
If Trouble Arises
Warning/Indicator Lights and Warning Sounds
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▼Low Fuel Warning Beep
When the low fuel warning light
fl
ashes, a warning beep is activated
once at the same time.
▼ Brake Override Warning Beep
A warning beep is activated when the
accelerator pedal and brake pedal are
depressed at the same time while
driving. Only depress the brake pedal.
▼Shift Position Warning Beep
A sound is activated when the push
button start is pressed while the
selector lever is in a position other
than P, and the ignition is switched to
ACC. Check the selector lever
position.
▼Electric Parking Brake (EPB)
War n in g Be ep
The warning buzzer is activated under
the following conditions:
The vehicle is driven with the parking
brake applied.
The Electric Parking Brake (EPB)
switch is pulled while the vehicle is
driven.
You attempt to start driving the
vehicle while the conditions for
releasing the Electric Parking Brake
(EPB) automatically have not been
met.
▼
AUTOHOLD Warning Beep
Warning light
flashes/message is
displayed and beep sound is activated
simultaneously for about 5 seconds
when using AUTOHOLD function or
when AUTOHOLD switch is operated.
Because a problem with AUTOHOLD
function has occurred, AUTOHOLD
function does not operate even if
AUTOHOLD switch is operated.

If the warning light flashes/message is
displayed and the beep sound is
activated simultaneously, have your
vehicle inspected at an Authorized
Mazda Dealer.
▼ Vehicle Problem Warning Beep
If any of the following problems occur,
a warning beep is activated. Check the
information regarding the warning
indication in the instrument cluster or
on the center display.
Automatic transmission problemIncrease in automatic transmission
internal temperature
Brake
fluid amount decreaseEngine oil level sensor problemElectric Parking Brake (EPB) problemEngine hydraulic pressure decreaseEngine coolant temperature increaseEngine system problem
If Trouble Arises
Warning/Indicator Lights and Warning Sounds
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Index
F
FlasherHazard warning.................... 4-60
Headlights............................4-46
Flat Tire Changing a flat tire................. 7-7
Mounting the spare tire........ 7-12
Removing a flat tire................ 7-8
Floor Mat................................. 3-46
Fluids Brake/Clutch........................6-21
Classi fication.......................... 9-5
Washer................................ 6-22
Foot Brake................................ 4-65
Forward Sensing Camera (FSC) ..........
.............................................. 4-203
Front Camera/Side Cameras/Rear
Camera.................................. 4-213
Front Cross Tra ffic Alert (FCTA) ..........
.............................................. 4-113
Front Cross Traffic Alert (FCTA)
Warning Beep........................... 7-46
Front Radar Sensor.................. 4-207
Front Side Radar Sensor........... 4-209
Fuel Filler lid and cap...................3-27
Requirements....................... 3-25
Tank capacity......................... 9-5
Fuses........................................ 6-40 Panel description.................. 6-43
Replacement........................ 6-40
G
Gauges..................................... 4-12
Glove Compartment..................5-46
H
Hazardous Driving.....................3-45
Hazard Warning Flasher............. 4-60
HeadlightsComing home light...............4-50
Flashing................................4-49
High-low beam.................... 4-49
Leaving home light............... 4-50
Leveling................................4-51
Head Restraint.......................... 2-17
High Beam Control System
(HBC)....................................... 4-90 High Beam Control System (HBC)
indicator light (green)........... 4-91
Hill Launch Assist (HLA)............. 4-75
HomeLink Wireless Control
System...................................... 4-60
Hood Release........................... 6-13
Horn........................................ 4-59
I
If a Warning Light Turns On or
Flashes......................................7-27
If the Active Driving Display Does Not
Operate.................................... 7-50
Ignition Not Switched O ff (STOP)
Warning Beep........................... 7-43
Ignition Switch............................ 4-4
Illuminated Entry System............ 5-41
Immobilizer System................... 3-40
Inside Trunk Release Lever......... 3-24
Inspecting Brake/Clutch Fluid
Level.........................................6-21
Inspecting Coolan t Level............ 6-20
Inspecting Engine Oil Level.........6-19
Inspecting Washer Fluid Level..... 6-22
Instrument Cluster..................... 4-12 Average fuel economy...........4-20
Compass display.................. 4-21
Current fuel economy........... 4-20
Dashboard illumination........ 4-18
Distance-to-empty................4-20
10-4
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