2020 INFINITI QX50 check engine

2. Have the belt checked regularly for con-dition.
REPLACING SPARK PLUGS
Iridium-tipped spark plugs
It is not necessary to replace iridium-tipped
Aspark plugs as frequently as conventional
type spark plugs because they last much lon-
ger. Follow the maintenance log shown in the
"Maintenance and schedules" section of this
manual. Do not service iridium-tipped spark
plugs by cleaning or regapping.
∙ Always replace spark plugs with recom-
mended or equivalent ones.
WARNING
Be sure the engine and ignition switch are
off and that the parking brake is engaged
securely.
CAUTION
Be sure to use the correct socket to remove
the spark plugs. An incorrect socket can
damage the spark plugs.
If replacement is required, it is recommended
that you visit an INFINITI retailer for this
service.
SDI1895
SPARK PLUGS
8-14Do-it-yourself

If the brakes do not operate properly, it is
recommended that you have the brakes
checked. It is recommended that you visit an
INFINITI retailer for this service.
Self-adjusting brakes
Your vehicle is equipped with self-adjusting
brakes.
The front and rear disc-type brakes self-
adjust every time the brake pedal is applied.
WARNING
Have your brake system checked if the
brake pedal height does not return to nor-
mal. It is recommended that you visit an
INFINITI retailer for this service.
Brake pad wear indicators
The disc brake pads on your vehicle have
audible wear indicators. When a brake pad
requires replacement, a high pitched scraping
or screeching sound will be heard when the
vehicle is in motion. The noise will be heard
whether or not the brake pedal is depressed.
Have the brakes checked as soon as possible
if the wear indicator sound is heard.Under some driving or climate conditions, oc-
casional brake squeak, squeal or other noise
may be heard. Occasional brake noise during
light to moderate stops is normal and does
not affect the function or performance of the
brake system.
Proper brake inspection intervals should be
followed.
For additional information regard-
ing brake inspections, refer to the appropri-
ate maintenance schedule information in the
"Maintenance and schedules" section of this
manual.
If any electrical equipment does not operate,
check for an open fuse.
Fuses are used in the passenger and engine
compartment. Spare fuses are provided and
can be found in the passenger compartment
fuse box.
When installing a fuse make sure the fuse is
installed in the fuse box securely.
LDI2997
BRAKES FUSES
8-18Do-it-yourself

ENGINE COMPARTMENT
WARNING
Never use a fuse of higher or lower amper-
age rating than that specified on the fuse
box cover. This could damage the electrical
system or electronic control units or cause a
fire.If any electrical equipment does not come on,
check for an open fuse.
1. Be sure the ignition switch and the head- light switch are OFF.
2. Open the engine hood.
3. Remove the fuse box cover by pushing the tabs and lifting the cover up.
4. Remove the fuse with the fuse puller. The fuse puller is located in the fuse
block in the passenger compartment.
5. If the fuse is open
A, replace it with a
new fuse
B.
6. If a new fuse also opens, have the elec- trical system checked and repaired. It is
recommended that you visit an INFINITI
retailer for this service.
Fusible links
If the electrical equipment does not operate
and fuses are in good condition, check the
fusible links. If any of these fusible links are
melted, replace with only Genuine NISSAN
parts.
LDI3174LDI3200
Do-it-yourself8-19

Some day-to-day and regular maintenance is
essential to maintain your vehicle good me-
chanical condition, as well as its emissions
and engine performance.
It is the owner’s responsibility to make sure
that the scheduled maintenance, as well as
general maintenance, is performed.
As the vehicle owner, you are the only one
who can ensure that your vehicle receives
proper maintenance. You are a vital link in the
maintenance chain.
GENERAL MAINTENANCE
General maintenance includes those items
which should be checked during normal day-
to-day operation. They are essential for
proper vehicle operation. It is your responsi-
bility to perform these procedures regularly
as prescribed.
Performing general maintenance checks re-
quires minimal mechanical skill and only a few
general automotive tools.
These checks or inspections can be done by
yourself, a qualified technician or, if you pre-
fer, an INFINITI retailer.
SCHEDULED MAINTENANCE
The maintenance items listed in this section
are required to be serviced at regular inter-
vals. However under severe driving condi-
tions, additional or more frequent mainte-
nance will be required.
WHERE TO GO FOR SERVICE
If maintenance service is required or your
vehicle appears to malfunction, have the sys-
tems checked and serviced. It is recom-
mended that you visit an INFINITI retailer for
this service.
INFINITI technicians are well-trained spe-
cialists and are kept up-to-date with the lat-
est service information through technical bul-
letins, service tips and training programs.
They are fully qualified to work on INFINITI
vehiclesbeforework begins.
If your vehicle is involved in a collision, it is
recommended that you ask your INFINITI
retailer where the nearest INFINITI Certified
Collision Center is located, or go to
http://collision.infinitiusa.com.
You can be confident that an INFINITI retail-
er’s service department can perform the ser-
vice needed to meet the maintenance re-
quirements on your vehicle. During the normal day-to-day operation of
the vehicle, general maintenance should be
performed regularly as prescribed in this sec-
tion. If you detect any unusual sounds, vibra-
tions or smells, be sure to check for the cause
or have it checked promptly. In addition, it is
recommended that you visit an INFINITI re-
tailer if you think that repairs are required.
When performing any checks or maintenance
work, closely observe the “Maintenance pre-
cautions” in the “Do-it-yourself” section of
this manual.
EXPLANATION OF GENERAL
MAINTENANCE ITEMS
Additional information on the following
items with“*”isfound in the “Do-it-
yourself” section of this manual.
Outside the vehicle
The maintenance items listed here should be
performed from time to time, unless other-
wise specified.
Doors and engine hood:
Check that the doors
and engine hood operate properly. Also en-
sure that all latches lock securely. Lubricate
hinges, latches, latch pins, rollers and links if
necessary. Make sure that the secondary
latch keeps the hood from opening when the
primary latch is released.
MAINTENANCE REQUIREMENTS GENERAL MAINTENANCE
9-2Maintenance and schedules

Seat belts:Check that all parts of the seat
belt system (for example, buckles, anchors,
adjusters and retractors) operate properly
and smoothly, and are installed securely.
Check the belt webbing for cuts, fraying,
wear or damage.
Seats: Check seat position controls such as
seat adjusters, seatback recliner, etc., to en-
sure they operate smoothly and all latches
lock securely in every position. Check that the
head restraints/headrests move up and
down smoothly and the locks (if so equipped)
hold securely in all latched positions.
Steering wheel: Check for changes in the
steering system, such as excessive free play,
hard steering or strange noises.
Warning lights and chimes: Make sure all
warning lights and chimes are operating
properly.
Windshield defroster: Check that the air
comes out of the defroster outlets properly
and in sufficient quantity when operating the
heater or air conditioner.
Windshield wiper and washer*: Check that
the wipers and washer operate properly and
that the wipers do not streak.Under the hood and vehicle
The maintenance items listed here should be
checked periodically (for example, each time
you check the engine oil or refuel).
Battery (for maintenance free batteries)*:
This vehicle is equipped with a sealed main-
tenance free battery. It is recommended that
you visit an INFINITI retailer for this service.
NOTE:
Care should be taken to avoid situations
that can lead to potential battery discharge
and potential no-start conditions such as:
1. Installation or extended use of elec-
tronic accessories that consume battery
power when the engine is not running
(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.
Brake fluid level*: Make sure that the brake
fluid level is between the MAX and MIN lines
on the reservoir.
Engine coolant level*: Check the coolant level
when the engine is cold. Engine drive belt*:
Make sure the drive belt is
not frayed, worn, cracked or oily.
Engine oil level*: Check the level after parking
the vehicle on a level spot and turning off the
engine. Wait more than 15 minutes for the oil
to drain back into the oil pan.
Exhaust system: Make sure there are no
loose supports, cracks or holes. If the sound
of the exhaust seems unusual or there is a
smell of exhaust fumes, immediately have the
exhaust system inspected. It is recommended
that you visit an INFINITI retailer for this
service. For additional information, refer to
“Exhaust gas (carbon monoxide)” in the
“Starting and driving” section of this manual.
Fluid leaks: Check under the vehicle for fuel,
oil, water or other fluid leaks after the vehicle
has been parked for a while. Water dripping
from the air conditioner after use is normal. If
you should notice any leaks or if fuel fumes
are evident, check for the cause and have it
corrected immediately.
Radiator and hoses: Check the front of the
radiator and clean off any dirt, insects, leaves,
etc., that may have accumulated. Make sure
the hoses have no cracks, deformation, rot or
loose connections.
9-4Maintenance and schedules

Underbody:The underbody is frequently ex-
posed to corrosive substances such as those
used on icy roads or to control dust. It is very
important to remove these substances, oth-
erwise rust may form on the floor pan, frame,
fuel lines and around the exhaust system. At
the end of winter, the underbody should be
thoroughly flushed with plain water, being
careful to clean those areas where mud and
dirt may accumulate. For additional informa-
tion, refer to the “Appearance and care” sec-
tion of this manual.
Windshield-washer fluid*: Check that there
is adequate fluid in the reservoir. The following descriptions are provided to
give you a better understanding of the sched-
uled maintenance items that should be regu-
larly checked or replaced. The maintenance
schedule indicates at which mileage/time in-
tervals each item requires service.
In addition to scheduled maintenance, your
vehicle requires that some items be checked
during normal day-to-day operation. For ad-
ditional information, refer to “General main-
tenance” in this section.
Items marked with
“*”are recommended by
INFINITI for reliable vehicle operation. You
are not required to perform maintenance on
these items in order to maintain the warran-
ties which come with your INFINITI. Other
maintenance items and intervals are required.
When applicable, additional information can
be found in the “Do-it-yourself” section of
this manual. NOTE:
INFINITI does not advocate the use of non-
OEM approved aftermarket flushing sys-
tems and strongly advises against perform-
ing these services on an INFINITI product.
Many of the aftermarket flushing systems
use non-OEM approved chemicals or sol-
vents, the use of which has not been vali-
dated by INFINITI.
For recommended fuel, lubricants, fluids,
grease, and refrigerant, refer to “Recom-
mended fluids/lubricants and capacities” in
the “Technical and consumer information”
section of this manual.
EMISSION CONTROL SYSTEM
MAINTENANCE:
Drive belt*:
Check engine drive belt for wear,
fraying or cracking and for proper tension.
Replace any damaged drive belt.
Engine air filter: Replace at specified inter-
vals. When driving for prolonged periods in
dusty conditions, check/replace the filter
more frequently.
EXPLANATION OF SCHEDULED
MAINTENANCE ITEMS
Maintenance and schedules9-5

Engine coolant*:Replace coolant at the
specified interval. When adding or replacing
coolant, be sure to use only Genuine NISSAN
Long Life Antifreeze/Coolant (blue) or
equivalent with the proper mixture. (For ad-
ditional information on the proper mixture for
your area, refer to “Engine cooling system” in
the “Do-it-yourself” section of this manual.)
NOTE: Mixing any other type of coolant or
the use of non-distilled water may reduce
the recommended service interval of the
coolant.
Engine oil and oil filter: Replace engine oil
and oil filter at the specified intervals. For
recommended oil grade and viscosity refer to
“Recommended fluids/lubricants and capaci-
ties” in the “Technical and consumer informa-
tion” section of this manual.
Engine valve clearance*: Inspect only if valve
noise increases. Adjust valve clearance if nec-
essary.
Evaporative emissions control vapor lines*:
Check vapor lines for leaks or looseness.
Tighten connections or replace parts as nec-
essary. Fuel lines*:
Check the fuel hoses, piping and
connections for leaks, looseness, or deterio-
ration. Tighten connections or replace parts
as necessary.
Spark plugs: Replace at specified intervals.
Install new plugs of the same type as origi-
nally equipped.
CHASSIS AND BODY
MAINTENANCE:
Brake lines and cables: Visually inspect for
proper installation. Check for chafing, cracks,
deterioration, and signs of leaking. Replace
any deteriorated or damaged parts immedi-
ately.
Brake pads and rotors: Check for wear, de-
terioration and fluid leaks. Replace any dete-
riorated or damaged parts immediately.
Exhaust system: Visually inspect the exhaust
pipes, muffler and hangers for leaks, cracks,
deterioration, and damage. Tighten connec-
tions or replace parts as necessary.
In-cabin microfilter: Replace at specified in-
tervals. When driving for prolonged periods in
dusty conditions, replace the filter more fre-
quently. Propeller shaft(s):
Check for damage, loose-
ness, and grease leakage. (AWD)
Steering gear and linkage, axle and suspen-
sion parts, drive shaft boots: Check for dam-
age, looseness, and leakage of oil or grease.
Under severe driving conditions, inspect more
frequently.
Tire rotation: Tires should be rotated every
7,500 miles (12,000 km) according to the
instructions under “Explanation of general
maintenance items” in this section. When ro-
tating tires, check for damage and uneven
wear. Replace if necessary.
Transmission fluid/oil, differential oil and
transfer case oil: Visually inspect for signs of
leakage at specified intervals.
Replace at specified intervals.
9-6Maintenance and schedules

E–15 fuel
E-15 fuel is a mixture of approximately 15%
fuel ethanol and 85% unleaded gasoline.
E-15 can only be used in vehicles designed to
run on E-15 fuel. U.S. government regula-
tions require fuel ethanol dispensing pumps
to be identified with small, square, orange
and black label with the common abbrevia-
tion or the appropriate percentage for that
region.
E–85 fuel
E-85 fuel is a mixture of approximately 85%
fuel ethanol and 15% unleaded gasoline.
E-85 can only be used in a Flexible Fuel Ve-
hicle (FFV). Do not use E-85 in your vehicle.
U.S. government regulations require fuel
ethanol dispensing pumps to be identified by
a small, square, orange and black label with
the common abbreviation or the appropriate
percentage for that region.
Fuel containing MMT
MMT, or methylcyclopentadienyl manganese
tricarbonyl, is an octane boosting additive.
INFINITI does not recommend the use of fuel
containing MMT. Such fuel may adversely
affect vehicle performance, including the
emissions control system. Note that while
some fuel pumps label MMT content, not alldo, so you may have to consult your gasoline
retailer for more details.
Aftermarket fuel additives
INFINITI does not recommend the use of any
aftermarket fuel additives (for example, fuel
injector cleaner, octane booster, intake valve
deposit removers, etc.) which are sold com-
mercially. Many of these additives intended
for gum, varnish or deposit removal may con-
tain active solvents or similar ingredients that
can be harmful to the fuel system and engine.
Octane rating tips
Using unleaded gasoline with an octane rat-
ing lower than recommended can cause per-
sistent, heavy “spark knock.” (“Spark knock”
is a metallic rapping noise.) If severe, this can
lead to engine damage. If you detect a per-
sistent heavy spark knock even when using
gasoline of the stated octane rating, or if you
hear steady spark knock while holding a
steady speed on level roads, it is recom-
mended that you have an INFINITI retailer
correct the condition. Failure to correct the
condition is misuse of the vehicle, for which
INFINITI is not responsible.
Incorrect ignition timing may result in spark
knock, after-run and/or overheating, which
may cause excessive fuel consumption or en-
gine damage. If any of the above symptoms
are encountered, have your vehicle checked.
It is recommended that you visit an INFINITI
retailer.
However, now and then you may notice light
spark knock for a short time while accelerat-
ing or driving up hills. This is not a cause for
concern, because you get the greatest fuel
benefit when there is light spark knock for a
short time under heavy engine load.
Technical and consumer information10-5