Page 440 of 498

CAUTION
.Do not ground accessories directly to the
battery terminal. Doing so will bypass
the variable voltage control system and
the vehicle battery may not charge
completely.
. Use electrical accessories with the en-
gine running to avoid discharging the
vehicle battery.
The variable voltage control system mea-
sures the amount of electrical discharge
from the battery and controls voltage
generated by the generator.SDI2119
VQ37VHR engine
1. Power steering fluid pump
2. Alternator
3. Crankshaft pulley
4. Air conditioner compressor
5. Drive belt auto-tensioner
WARNING
Be sure the ignition switch is in the OFF or
LOCK position before servicing drive belts.
The engine could rotate unexpectedly.
1. Visually inspect each belt for signs of
unusual wear, cuts, fraying or loosen- ess. If the belt is in poor condition or
loose, have it replaced or adjusted by
an INFINITI retailer.
2. Have the belts checked regularly for condition and tension in accordance
with the maintenance schedule in your
“INFINITI Service and Maintenance
Guide”.
Maintenance and do-it-yourself8-17
VARIABLE VOLTAGE CONTROL SYSTEM DRIVE BELTS
Page 441 of 498
8-18Maintenance and do-it-yourself
WARNING
Be sure the engine and the 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.
SDI2020
REPLACING SPARK PLUGS
If replacement is required, see an INFINITI
retailer for servicing.
Iridium-tipped spark plugs
It is not necessary to replace the iridium-
tipped spark plugs as frequently as the
conventional type spark plugs since they
will last much longer. Follow the main-
tenance schedule in“INFINITI Service and
Maintenance Guide” , but do not reuse
them by cleaning or regapping. Always replace spark plugs with recom-
mended or equivalent ones.
SPARK PLUGS
Page 442 of 498
SDI2033
Remove the retainers*1as illustrated and
pull out the filter element
*2.
The filter element should not be cleaned
and reused. Replace it according to the
maintenance intervals. See “INFINITI Ser-
vice and Maintenance Guide” for mainte-
nance intervals. When replacing the filter, wipe the inside of the air cleaner housing
and the cover with a damp cloth.
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 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 careful 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.
Maintenance and do-it-yourself8-19
AIR CLEANER
Page 444 of 498

SDI2362
If you wax the surface of the hood, be
careful not to let wax get into the washer
nozzle
*A. This may cause clogging or
improper windshield washer operation. If
wax gets into the nozzle, remove it with a
needle or small pin
*B. Be careful not to
damage the nozzle. Contact an INFINITI retailer if checking or
replacement is required.
If the brakes do not operate properly, have
the brakes checked by an INFINITI retailer.
SELF-ADJUSTING BRAKES
Your vehicle is equipped with self-adjust-
ing brakes.
The disc-type brakes self-adjust every time
the brake pedal is applied.
WARNING
See an INFINITI retailer for a brake system
check if the brake pedal height does not
return to normal.
BRAKE PAD WEAR WARNING
The disc brake pads have audible wear
warnings. When a brake pad requires
replacement, it will make a high pitched
scraping sound when the vehicle is in
motion. This scraping sound will first occur
only when the brake pedal is depressed.
After more wear of the brake pad, the
sound will always be heard even if the
brake pedal is not depressed. Have the
brakes checked as soon as possible if the
wear warning sound is heard.
Under some driving or climate conditions,
Maintenance and do-it-yourself8-21
REAR WINDOW WIPER BLADES
BRAKES
Page 450 of 498

HEADLIGHTS
Replacing
Fog may temporarily form inside the lens of
the exterior lights in the rain or in a car
wash. A temperature difference between
the inside and the outside of the lens
causes the fog. This is not a malfunction. If
large drops of water collect inside the lens,
contact an INFINITI retailer.
Xenon headlight bulb (if so equipped):
If replacement is required, see an INFINITI
retailer.
WARNING
HIGH VOLTAGE
When xenon headlights are on, they pro-
duce a high voltage. To prevent an electric
shock, never attempt to modify or disas-
semble. Always have your xenon headlights
replaced at an INFINITI retailer. For addi-
tional information, see “Headlight and turn
signal switch” in the“2. Instruments and
controls” section.
Halogen headlight bulb (if so equipped):
The headlight is a semi-sealed beam type
which uses a replaceable headlight (halo-
gen) bulb. If replacement is required, see
an INFINITI retailer for servicing.
CAUTION
.High pressure halogen gas is sealed
inside the bulb. The bulb may break if
the glass envelope is scratched or the
bulb is dropped.
. Only touch the plastic base when hand-
ling the bulb. Never touch the glass
envelope. Touching the glass could sig-
nificantly affect bulb life and/or head-
light performance.
. Do not leave the bulb out of the head-
light reflector for a long period of time
as dust, moisture, and smoke may enter
the headlight body and affect the
performance of the headlight.
. Aiming is not necessary after replacing
the bulb. When aiming adjustment is
necessary, contact an INFINITI retailer.
Maintenance and do-it-yourself8-27
Page 453 of 498

8-30Maintenance and do-it-yourself
SDI1500B
Cargo light
SDI1839
Vanity mirror lightIf you have a flat tire, see
“Flat tire”in the
“6. In case of emergency” section.
TIRE PRESSURE
Tire Pressure Monitoring System
(TPMS)
This vehicle is equipped with the Tire
Pressure Monitoring System (TPMS). It
monitors tire pressure of all tires except
the spare. When the low tire pressure
warning light is lit and the CHECK TIRE
PRESSURE warning appears on the dot
matrix liquid crystal display, one or more
of your tires is significantly under-inflated.
The TPMS will activate only when the
vehicle is driven at speeds above 16 MPH
(25 km/h). Also, this system may not
detect a sudden drop in tire pressure (for
example a flat tire while driving).
For more details, see“Low tire pressure
warning light” in the“2. Instruments and
controls” section,“Tire Pressure Monitor-
ing System (TPMS)” in the“5. Starting and
driving” section and “Tire Pressure Mon-
itoring System (TPMS) ”in the “6. In case
of emergency” section.
Tire inflation pressure
Check the pressure of the tires
(including the spare) often and al-
ways prior to long distance trips. The
recommended tire pressure specifi-
cations are shown on the Tire and
Loading Information label under the
“Cold Tire Pressure” heading. The
Tire and Loading Information label is
affixed to the driver side center pillar.
Tire pressures should be checked
regularly because:
.Most tires naturally lose air over time.
.Tires can lose air suddenly whendriven over potholes or other
objects or if the vehicle strikes a
curb while parking.
The tire pressures should be checked
when the tires are cold. The tires are
considered COLD after the vehicle
has been parked for 3 or more hours,
or driven less than 1 mile (1.6 km) at
moderate speeds.
WHEELS AND TIRES
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Incorrect tire pressure, including
under inflation, may adversely affect
tire life and vehicle handling.
WARNING
.Improperly inflated tires can fail
suddenly and cause an accident.
. The Gross Vehicle Weight rating
(GVWR) is located on the F.M.V.S.
S./C.M.V.S.S. certification label.
The vehicle weight capacity is
indicated on the Tire and Loading
Information label. Do not load
your vehicle beyond this capacity.
Overloading your vehicle may re-
sult in reduced tire life, unsafe
operating conditions due to pre-
mature tire failure, or unfavorable
handling characteristics and could
also lead to a serious accident.
Loading beyond the specified ca-
pacity may also result in failure of
other vehicle components. .
Before taking a long trip, or
whenever you heavily load your
vehicle, use a tire pressure gauge
to ensure that the tire pressures
are at the specified level.
. For additional information regard-
ing tires, refer to “Important Tire
Safety Information ”(US) or “Tire
Safety Information ”(Canada) in
the Warranty Information Booklet.
Maintenance and do-it-yourself8-31
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8-36Maintenance and do-it-yourself
bears white lettering or bears manu-
facturer, brand and/or model name
molding that is higher or deeper than
the same molding on the other side-
wall of the tire, or (2) the outward
facing sidewall of an asymmetrical
tire that has a particular side that
must always face outward when
mounted on a vehicle.
TYPES OF TIRES
WARNING
.When changing or replacing tires, be
sure all four tires are of the same type
(Example: Summer, All Season or Snow)
and construction. An INFINITI retailer
may be able to help you with information
about tire type, size, speed rating and
availability.
. Replacement tires may have a lower
speed rating than the factory equipped
tires, and may not match the potential
maximum vehicle speed. Never exceed
the maximum speed rating of the tire.
. Replacing tires with those not originally specified by INFINITI could affect the
proper operation of the TPMS.
. For additional information regarding
tires, refer to “Important Tire Safety
Information” (US) or“Tire Safety Infor-
mation” (Canada) in the Warranty Infor-
mation Booklet.
All season tires
INFINITI specifies all season tires on some
models to provide good performance all
year, including snowy and icy road condi-
tions. All Season tires are identified by ALL
SEASON and/or M&S (Mud and Snow) on
the tire sidewall. Snow tires have better
snow traction than All Season tires and
may be more appropriate in some areas.
Summer tires
INFINITI specifies summer tires on some
models to provide superior performance on
dry roads. Summer tire performance is
substantially reduced in snow and ice.
Summer tires do not have the tire traction
rating M&S on the tire sidewall.
If you plan to operate your vehicle in snowy
or icy conditions, INFINITI recommends the
use of SNOW tires or ALL SEASON tires on all four wheels.
Snow tires
If snow tires are needed, it is necessary to
select tires equivalent in size and load
rating to the original equipment tires. If
you do not, it can adversely affect the
safety and handling of your vehicle.
Generally, snow tires will have lower speed
ratings than factory equipped tires and
may not match the potential maximum
vehicle speed. Never exceed the maximum
speed rating of the tire.
If you install snow tires, they must be the
same size, brand, construction and tread
pattern on all four wheels.
For additional traction on icy roads,
studded tires may be used. However, some
U.S. states and Canadian provinces prohi-
bit their use. Check local, state and
provincial laws before installing studded
tires. Skid and traction capabilities of
studded snow tires, on wet or dry surfaces,
may be poorer than that of non-studded
snow tires.