2020 MAZDA MODEL 3 HATCHBACK Owners Manual (in English)

Traffic Jam Assist (TJA)*
▼Traffic Jam Assist (TJA)
The TJA is a system which consists of a
headway control function and a steering
assist function for reducing driver fatigue
during traffic jams when driving on
expressways or highways.
This system performs
headway control to
maintain a constant distance between your
vehicle and a vehicle ahead at a preset
vehicle speed without you having to use
the accelerator or brake pedal. Even
further, with the steering assist function,
when vehicle lane lines are detected, the
function assists the driver in keeping the
vehicle within the lan e lines. If lane lines
are not detected, the function provides the
driver driving assistance in keeping the
vehicle along the motion path with the
vehicle ahead.
WA R N I N G
Do not rely completely on TJA:
 The TJA is not an automated driving
system. In addition, the functions have
limitations. Do not rely completely on the
system and always stay on course using
the steering wheel.
 Set a vehicle speed within the speed limit
according to the road conditions and the
weather conditions.
The TJA may not be able to detect a
vehicle ahead depending on the type of
vehicle ahead and its conditions, the
weather conditions, and the road
conditions. Additionally, the system
might be unable to decelerate sufficiently
if a vehicle ahead applies the brakes
suddenly, another vehicle cuts into the
driving lane, or the difference in vehicle
speed between your vehicle and the
vehicle ahead is larger, which could
result in an accident. Check the
surrounding conditions and always drive
carefully while keeping a safe distance
from vehicles ahead and on-coming
vehicles.

For the purposes of safety, switch the TJA
off when it is not being used.
Leaving the TJA turned on when it is not in
use is dangerous as it could operate
unexpectedly, resulting in an accident.

Do not use the TJA under the following
conditions. Otherwise, it may result in an
accident.
 General roads other than expressways or
highways (Driving under these
conditions using the TJA is not possible.)
 Roads with sharp curves and where
vehicle traffic is heavy with insufficient
space between vehicles, or roads where
frequent and repetitive acceleration and
deceleration occur (Driving under these
conditions using the TJA is not possible).
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When entering and exiting interchanges,
service areas, and parking areas of
expressways (If you exit an expressway
while headway control is in use, the
vehicle ahead will no longer be tracked
and your vehicle may accelerate to the
set speed).
 Slippery roads such as icy or
snow-covered roads (Tires could spin
causing you to lose vehicle control, or the
stop hold control may not operate.)
 Long, descending slopes (to maintain
distance between vehicles, the system
automatically and continuously applies
the brakes which could result in the loss
of brake power.)
 Two-wheeled vehicles such as
motorcycles or bicycles are ahead.
 (Automatic transmission vehicle)
Slopes with a steep gradient (The vehicle
ahead may not be detected correctly,
your vehicle may slip while stopped by
the stop hold control, or it may
accelerate suddenly after it starts
moving.)
 Driving under bad weather conditions
(rain, fog, and snow).
 The vehicle is driven on slippery roads
such as icy or snow -covered roads and
unpaved roads (Tires could spin causing
you to lose vehicle control, or the stop
hold control may not operate.)
 Tires of a different specified size are used,
such as a temporary spare tire.
 Tires with insufficient tread are used.
 The tire pressures are not adjusted to the
specified pressure.
 The vehicle is being used to tow a
camper or boat trailer.
 Tire chains are used.The vehicle is driven on roads with lane
lines other than white (yellow) lines, such
as an expressway.

Do not get out of the vehicle while the stop
hold control is operating.
(Automatic transmission vehicle)
Getting out of the vehicle while the stop
hold control is operating is dangerous as
the vehicle may move unexpectedly and
result in an accident. Before getting out of
the vehicle, switch the TJA off, apply the
parking brake, and then shift the selector
lever to the P position.

CAUTION
Turn the system off when the vehicle is
running on a chassis roller.
Heed the following cautions so that the TJA
can operate normally.
 Turn the system off when the vehicle is
running on a chassis roller.
 Do not modify the vehicle's suspensions.
 Always use wheels of the specified size
for the front and rear wheels. Consult an
Authorized Mazda Dealer for tire
replacement.

NOTE
The headway control does not detect the
following as physical objects.
Vehicles approaching in the opposite
direction
Pedestrians
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Stationary objects (stopped vehicles,
obstructions)
If a vehicle ahead is traveling at an
extremely low speed, the system may not
detect it correctly.
If there is a structure on the road or an
object (such as a monorail) at a low
height off the ground in front of the
vehicle, the system may operate.
Therefore, do not use the TJA.
Do not use the TJA under conditions in
which close proximity warnings are
frequently activated.
If it is necessary to accelerate for a lane
change or the vehicle ahead brakes
suddenly causing you to close in on the
vehicle rapidly, accelerate using the
accelerator pedal or decelerate using
the brake pedal depending on the
conditions.
While the TJA is in use, any intended
engine braking does not occur even if
you shift the shift lever (manual
transmission) or the selector lever
(automatic transmission). If
deceleration is required, lower the
vehicle speed setting or depress the
brake pedal.
While braking by the TJA control is
operating, you might hear an operation
sound, however, this does not indicate a
problem.
The brake lights turn on while braking
by the TJA control is operating,
however, they may not turn on while the
vehicle is on a down slope at the set
vehicle speed or traveling at a constant
speed and following a vehicle ahead.
Under the following conditions, the TJA
may not be able to detect white (yellow)
lines or vehicles ahead correctly and the
TJA may not operate normally.
The forward sensing camera (FSC)
cannot recognize the area in front of
the vehicle due to soiling or fog.
The white (yellow) lane lines are less
visible because of dirt or paint
flaking.
White (yellow) lane lines or vehicles
ahead are less visible because of bad
weather (rain, fog, or snow).
The vehicle is driven on a temporary
lane or section with a closed lane
resulting from construction where
there might be multiple white (yellow)
lane lines, or they are interrupted.
The camera picks up an obscure line,
such as a temporary line being used
for construction, or because of shade,
unmelted snow, or grooves filled with
water.
The road surface is wet and shiny
after rain, or there are puddles on the
road.
Heavy luggage is loaded in the trunk/
luggage compartment or on the rear
seat causing the vehicle to tilt.
A vehicle in front of your vehicle is
running near a white (yellow) lane
line making it less visible.
The windshield is dirty or foggy.
The vehicle is driven through an
intersection, a junction, or a fork in
the road.
While white (yellow) lane lines cannot
be detected due to road or weather
conditions.
The surrounding brightness suddenly
changes such as when entering or
exiting a tunnel.
The illumination of the headlights is
weakened because of dirt or the
optical axis is deviated at night.
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Back-light is reflected off the road
surface or the road surface is wet and
shiny after rain.
The shade of a guardrail parallel to a
white (yellow) lane line is cast on the
road.
The width of a lane is excessively
narrow or wide.
The road is excessively uneven.
The vehicle is shaken after hitting a
road bump.
There are various road markings or
division lines (lane markings) of
various shapes near an intersection.
The area in front of the camera is
soiled or an object that obstructs the
field of view is installed.
Exhaust gas from the vehicle in front,
sand, snow, and water vapor rising
from manholes and grating, and water
splashed into the air.
The surroundings are dark such as
during the early evening or early
morning.
A vehicle ahead with a certain
taillight shape.
A vehicle ahead veers off course from
your vehicle's line of travel.
A vehicle ahead is driving erratically.
The vehicle is driven on roads with
tight curves.

Headway control function
If a vehicle ahead is detected while
traveling at a constant speed, the
vehicle-ahead indication is displayed and
headway control is performed.

Steering assist function
When lane lines are detected, the function
assists the driver in keeping the vehicle
within the lane lines. If lane lines are not
detected, the function provides the driver
driving assistance in keeping the vehicle
along the motion path with the vehicle
ahead.
NOTE
Steering assist limit warning
If the steering assist function cannot keep
the vehicle within the lane lines while the
steering assist function is operating, a
warning sound is activated and a warning
is displayed on the multi-information
display to urge the driver to operate the
steering wheel.
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▼Traffic Jam Assist (TJA) Display
Indication
The TJA setting status and operation
conditions are indicated on the
multi-information display or the active
driving display.
Multi-information display (Basic
display)
1. Vehicle ahead display
2. TJA set vehicle speed

Multi-information display
(i-ACTIVSENSE display)
1. Vehicle ahead display
2. TJA set vehicle speed

Active driving display
1. Vehicle ahead display
2. TJA set vehicle speed

Steering assist function display
When the steering assist function operates,
the steering assist operation display on the
display changes from white to green.
NOTE
You can view the multi-information display
to check whether the steering assist is
performing controls in conjunction with
the traffic lane lines or a vehicle ahead.
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Inactive
Active (vehicle ahead)
Active (lane line)
If there is a problem with the TJA, a
message is displayed on the
multi-information display. Check the
details of the problem on the center
display and then have your vehicle
inspected by an Authorized Mazda Dealer.
Refer to If a Warnin g Light Turns On or
Flashes on page 7-27.
▼ Close Proximity Warning
If your vehicle rapidly closes in on the
vehicle ahead while you are traveling
under headway control, the warning sound
is activated and the brake warning is
indicated on the display. Keep a safe
distance between your vehicle and a
vehicle ahead.
1. “Depress Brake Pedal” message is
displayed
NOTE
In the following cases, the warnings and
brakes may not operate even if your
vehicle starts closing in on the vehicle
ahead.
You are driving your vehicle at the same
speed as the vehicle ahead.
Directly after the TJA operates.
Directly after the accelerator pedal is
released.
Another vehicle cuts into the driving
lane.
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▼Setting the System
Operation conditions
Headway control function
The TJA operates when all of th
e following conditions are met.
(Automatic transmission vehicle)
The vehicle speed is about 0 km/h (0 mph) to 145 km/h (90 mph).
The selector lever is in the D or M position (manual mode).
(Manual transmission vehicle)
The vehicle speed is about 30 km/h (19 mph) to 145 km/h (90 mph ).
The shift lever is in a position other than the R or N position.
The clutch pedal is not depressed.
The TJA is operating.
The headway control function of the Mazda Radar Cruise Control (MRCC) or Mazda
Radar Cruise Control with Stop & Go function (MRCC with Stop & Go function) is set to
operable (if it was set to inope rable, set it to operable using the personalization function).
The brake pedal is not depressed.
The parking brake is released (E lectric Parking Brake (EPB) indicator light is turned off).
There is no problem with the DSC.
All the doors are closed.
The driver's seat belt is fastened.

NOTE
(Automatic transmission vehicle)
Under the following conditions, the TJA cannot be used when the vehicle speed is 30 km/h
(19 mph) or slower.
There is a problem with the stop hold control function.
There is a problem with the Electric Parking Brake (EPB).
The TJA may not launch directly after the engine starts.

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Steering assist function
The steering assist function operates when all of the following conditions are met.
Your vehicle is moving and less than about 56 km/h (35 mph).
White (yellow) lane lines on both sides are detected and you ar e driving near the center of
the lane, or your vehicle detects a vehicle ahead.
The steering wheel is not turned sharply.
The turn signal lever is not operated.
The headway control function is operating.
(Manual transmission vehicle)
The vehicle speed is about 30 km/h (19 mph) or faster.
NOTE
The steering assist function operates so that the vehicle remains near the center of the
driving lane, however, depending on conditions such as the road curvature, road slope and
undulations, and vehicle speed, th e function might not be able to keep the vehicle near the
center of the driving lane.
Setting method
1. CANCEL switch
2. RES switch
3. TJA switch

1. Press the TJA switch. The TJA standby indication (white) turns on. In addition, the T JA display indication is
displayed on the mu lti-information display at the same time.
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