service NISSAN SENTRA 2021 Repair Manual

SYSTEM MAINTENANCE
The sonar sensorsO1are located on the
rear bumper. Always keep the area near
the sonar sensors clean.
The sonar sensors may be blocked by tem-
porary ambient conditions such as splash-
ing water, mist or fog.
The blocked condition may also be caused
by objects such as ice, frost or dirt ob-
structing the sonar sensors.
Check for and remove objects obstructing
the area around the sonar sensors. Do not attach stickers (including transpar-
ent material), install accessories or apply
additional paint near the sonar sensors.
Do not strike or damage the area around
the sonar sensors. It is recommended that
you visit a NISSAN dealer if the area around
the sonar sensors is damaged due to a
collision.
FREEING A FROZEN DOOR LOCK
To prevent a door lock from freezing, apply
de-icer through the key hole. If the lock
becomes frozen, heat the key before in-
serting it into the key hole, or use the re-
mote keyless entry key fob or the NISSAN
Intelligent Key®.
ANTIFREEZE
In the winter when it is anticipated that the
temperature will drop below 32°F (0°C),
check the antifreeze to assure proper win-
ter protection. For additional information,
refer to “Engine cooling system” in the “Do-
it-yourself ” section of this manual.
BATTERY
If the battery is not fully charged during
extremely cold weather conditions, the
battery fluid may freeze and damage the
battery. To maintain maximum efficiency,
the battery should be checked regularly.
This vehicle is equipped with a sealed
maintenance free battery. It is recom-
mended that you visit a NISSAN dealer for
service.
LSD3754
COLD WEATHER DRIVING
Starting and driving5-125

6. Af ter the engine cools down, check thecoolant level in the engine coolant res-
ervoir with the engine running. Add cool-
ant to the engine coolant reservoir if
necessary. Have your vehicle repaired. It
is recommended that you visit a NISSAN
dealer for this service. When towing your vehicle, all State (Provin-
cial in Canada) and local regulations for
towing must be followed. Incorrect towing
equipment could damage your vehicle.
Towing instructions are available from a
NISSAN dealer. Local service operators are
generally familiar with the applicable laws
and procedures for towing. To assure
proper towing and to prevent accidental
damage to your vehicle, NISSAN recom-
mends having a service operator tow your
vehicle. It is advisable to have the service
operator carefully read the following pre-
cautions:CAUTION
• When towing, make sure that the
transmission, axles, steering system
and powertrain are in working condi-
tion. If any of these conditions apply,
dollies or a flatbed tow truck must be
used.
• Always attach safety chains before
towing.
For additional information, refer to “Flat
towing” in the “Technical and consumer in-
formation” section of this manual.
TOWING RECOMMENDED BY
NISSAN
NISSAN recommends towing your vehicle
based upon the type of drivetrain. For addi-
tional information, refer to the diagrams in
this section to ensure that your vehicle is
properly towed.
TOWING YOUR VEHICLE
6-12In case of emergency

When performing any inspection or main-
tenance work on your vehicle, always take
care to prevent serious accidental injury to
yourself or damage to the vehicle. The fol-
lowing are general precautions which
should be closely observed.CAUTION
• Do not work under the hood while
the engine is hot. Turn the engine off
and wait until it cools down.
• Avoid contact with used engine oil
and coolant. Improperly disposed
engine oil, engine coolant and/or
other vehicle fluids can damage the
environment. Always conform to lo-
cal regulations for disposal of vehicle
fluid.
• Never leave the engine or the trans-
mission related component harness
connector disconnected while the ig-
nition switch is in the ON position.
• Never connect or disconnect the bat-
tery or any transistorized compo-
nent while the ignition switch is in
the ON position.
This “Do-it-yourself ” section gives instruc-
tions regarding only those items which are
relatively easy for an owner to perform.
A Genuine NISSAN service manual is also
available. For additional information, refer
to “Owner's Manual/Service Manual order
information” in the “Technical and con-
sumer information” section of this manual.
MAINTENANCE PRECAUTIONS
8-2Do-it-yourself

CHECKING ENGINE COOLANT
LEVEL
Check the coolant levelin the reservoir
when the engine is cold. If the coolant
level is below the MIN level
OB, add coolant
to the MAX level
OA.
This vehicle contains Genuine NISSAN Long
Life Antifreeze/Coolant (blue). The life ex-
pectancy of the factory-fill coolant is
105,000 miles (168,000 km) or 7 years. Mixing
any other type of coolant or the use of
non-distilled water will reduce the life ex-
pectancy of the factory-fill coolant. For ad- ditional information, refer to the “Mainte-
nance and schedules” section of this
manual.
If the cooling system frequently requires
coolant, have it checked. It is recom-
mended that you visit a NISSAN dealer
for this service.
For additional information on the location
of the engine coolant reservoir, refer to “En-
gine compartment check locations” in this
section.
CHANGING ENGINE COOLANT
A NISSAN dealer can change the engine
coolant. The service procedure can be
found in the NISSAN Service Manual.
Improper servicing can result in reduced
heater performance and engine over-
heating.
WARNING
• To avoid the danger of being scalded,
never change the coolant when the
engine is hot.
• Never remove the engine coolant
reservoir cap when the engine is hot.
Serious burns could be caused by
high pressure fluid escaping from the
system. •
Avoid direct skin contact with used
coolant. If skin contact is made, wash
thoroughly with soap or hand
cleaner as soon as possible.
• Keep coolant out of the reach of chil-
dren and pets.
Engine coolant must be disposed of prop-
erly. Check your local regulations.
LDI3495
8-6Do-it-yourself

CAUTION
• NISSAN recommends using Genuine
NISSAN CVT Fluid NS-3 (or equiva-
lent) ONLY in NISSAN CVTs. Do not mix
with other fluids.
• Do not use Automatic Transmission
Fluid (ATF) or manual transmission
fluid in a NISSAN CVT, as it may dam-
age the CVT. Damage caused by the
use of fluids other than as recom-
mended is not covered under
NISSAN's New Vehicle Limited
Warranty.
• Using fluids that are not equivalent
to Genuine NISSAN CVT Fluid NS-3
may also damage the CVT. Damage
caused by the use of fluids other than
as recommended is not covered un-
der NISSAN's New Vehicle Limited
Warranty.
When checking or replacement of CVT fluid
is required, it is recommended that you visit
a NISSAN dealer for servicing. For additional brake and clutch fluid speci-
fication information, refer to “Recom-
mended fluids/lubricants and capacities”
in the “Technical and consumer informa-
tion” section of this manual.
CAUTION
Do not spill the fluid on any painted sur-
faces. This will damage the paint. If fluid
is spilled, immediately wash the sur-
face with water.
BRAKE FLUID
Check the fluid level in the reservoir. If the
level is below the MIN line
O1, or the brake
warning light comes on, add Genuine
NISSAN Brake Fluid or equivalent DOT 3
fluid up to the MAX line
O2. If fluid must be
added frequently, the system should be
checked. It is recommended that you visit a
NISSAN dealer for this service.
LDI3490
CONTINUOUSLY VARIABLE
TRANSMISSION (CVT) FLUID (if so
equipped) BRAKE AND CLUTCH (if so equipped)
FLUID

CLUTCH (if so equipped) FLUID
Check the fluid level in the reservoir. If the
level is below the MIN line
O1, or the brake
warning light comes on, add Genuine
NISSAN Brake Fluid or equivalent DOT 3
fluid up to the MAX line
O2. If fluid must be
added frequently, the system should be
checked. It is recommended that you visit a
NISSAN dealer for this service.
WINDSHIELD-WASHER FLUID
RESERVOIR
Fill the windshield-washer fluid reservoir
periodically. Add windshield-washer fluid
when the low windshield-washer fluid
warning light (if so equipped) comes on or
the “Low Washer Fluid” warning message
shows on the vehicle information display.
To check the fluid level, use your finger to
plug the center hole
O1of the cap/tube
assembly, then remove it from the reser-
voir. If there is no fluid in the tube, add fluid.
Add a washer solvent to the washer for
better cleaning. In the winter season, add a windshield washer antifreeze. Follow the
manufacturer's instructions for the mix-
ture ratio.
Refill the reservoir more frequently when
driving conditions require an increased
amount of windshield-washer fluid.
Recommended fluid is Genuine NISSAN
Windshield Washer Concentrate Cleaner &
Anti-freeze or equivalent.
LDI3496
WINDSHIELD-WASHER FLUID
Do-it-yourself8-11

• If the battery is labeled “do not open” it ismaintenance free and battery fluid
should not be checked. It is recom-
mended that you visit a NISSAN dealer or
a qualified specialist workshop to con-
firm the battery’s performance.
• Keep the battery surface clean and dry. Clean the battery with a solution of bak-
ing soda and water.
• Make certain the terminal connections are clean and securely tightened.
• If the vehicle is not to be used for 30 days or longer, disconnect the negative (-) bat-
tery terminal cable to prevent discharge.
NOTE:
Care should be taken to avoid situations
that can lead to potential battery dis-
charge and potential no-start conditions
such as:
1. Installation or extended use of elec-
tronic accessories that consume bat-
tery power when the engine is not run-
ning (Phone chargers, GPS, DVD
players, etc.)
2. Vehicle is not driven regularly and/or
only driven short distances.
In these cases, the battery may need to
be charged to maintain battery health.
WARNING
• Do not expose the battery to flames,
an electrical spark or a cigarette. Hy-
drogen gas generated by the battery
is explosive. Explosive gases can
cause blindness or injury. Do not al-
low battery fluid to contact your skin,
eyes, fabrics or painted surfaces. Sul-
furic acid can cause blindness or in-
jury. Af ter touching a battery or bat-
tery cap, do not touch or rub your
eyes. Thoroughly wash your hands. If
the acid contacts your eyes, skin or
clothing, immediately flush with wa-
ter for at least 15 minutes and seek
medical attention.
• When working on or near a battery,
always wear suitable eye protection
and remove all jewelry.
• Battery posts, terminals and related
accessories contain lead and lead
compounds. Wash hands af ter
handling.
• Keep battery out of the reach of
children.
• Do not tip the battery.
NOTE:
Do not try to open the top of the battery.
This battery is not equipped with remov-
able vent caps.
JUMP STARTING
If jump starting is necessary, refer to “Jump
starting” in the “In case of emergency” sec-
tion of this manual. If the engine does not
start by jump starting, the battery may
have to be replaced. It is recommended
that you visit a NISSAN dealer for this
service.
LDI3302

1. Visually inspect the belt for signs of un-usual wear, cuts, or fraying. If the belt is in
poor condition, have it replaced or ad-
justed. It is recommended that you visit a
NISSAN dealer for this service.
2. Have the belt checked regularly for condition.
REPLACING SPARK PLUGS
CAUTION
Be sure to use the correct socket to re-
move the spark plugs. An incorrect
socket can damage the spark plugs.
Iridium-tipped spark plugs
It is not necessary to replace iridium-
tipped
OAspark plugs as frequently as con-
ventional type spark plugs because they
last much longer. Follow the maintenance
log shown in the “Maintenance and sched-
ules” section of this manual. Do not service
platinum-tipped spark plugs by cleaning or
regapping.
• Always replace spark plugs with rec-
ommended or equivalent ones.
If replacement is required, it is recom-
mended that you visit a NISSAN dealer for
this service.
SDI1895
SPARK PLUGS
Do-it-yourself8-15

The viscous paper type filter element (if so
equipped) should not be cleaned and re-
used. The dry paper type filter element (if so
equipped) may be cleaned an reused. Re-
place it according to the maintenance log
shown in the “Maintenance and schedules”
section of this manual.
To remove the air cleaner filter:
1. Unlatch the retaining clips
OA.
2. Pull up at points
OBand remove.
3. Pull up and remove air cleaner housing. 4. Remove the air cleaner filter. Wipe the
inside of the air cleaner filter housing
and the cover with a damp cloth, then
replace air cleaner filter.
NOTE:
Af ter installing a new air cleaner, make
sure the air cleaner cover is seated in the
housing and latch the clips.
WARNING
• Operating the engine with the air
cleaner removed can cause you or
others to be burned. The air cleaner
not only cleans the air, it stops the
flame if the engine backfires. If it isn't
there, and the engine backfires, you
could be burned. Do not drive with
the air cleaner removed, and be care-
ful when working on the engine with
the air cleaner removed.
• Never pour fuel into the throttle body
or attempt to start the engine with
the air cleaner removed. Doing so
could result in serious injury.
IN-CABIN MICROFILTER
The in-cabin microfilter restricts the entry
of airborne dust and pollen particles and
reduces some objectionable outside
odors. The filter is located behind the glove
box. For additional information, refer to the
“Maintenance and schedules” section of
this manual for change intervals.
If replacement is required, it is recom-
mended that you visit a NISSAN dealer for
this service.
LDI3498
AIR CLEANER

3. Remove the fuse box cover by pushingthe tabs
OAand lif ting the cover up.
4. Remove the fuse with the fuse puller, which is located in the center of the fuse
box cover in the passenger compart-
ment. For additional information, refer to
“Passenger Compartment” in the “Do-it
yourself ” section of this manual.
5. If the fuse is open
OB, replace it with an
equivalent good fuse
OC.
6. Push the fuse box cover to install.
If a new fuse also opens, have the electrical
system checked and repaired. It is recom-
mended that you visit a NISSAN dealer for
this service.
NOTE:
Your vehicle may not be equipped with
all fuses listed on the fuse label.
Fusible links
If the electrical equipment does not oper-
ate and fuses are in good condition, check
the fusible links. If any of these fusible links
are melted, replace with only Genuine
NISSAN parts.
LDI2746
8-20Do-it-yourself