2003 NISSAN SENTRA check engine

1. Visually inspect each belt for signs of un-
usual wear, cuts, fraying or looseness. If the
belt is in poor condition or is loose, have it
replaced or adjusted by a NISSAN dealer.
2. Have the belts checked regularly for condi-
tion and tension in accordance with the
maintenance schedule found in the
“NISSAN Service and Maintenance Guide”.
1. Power steering fluid pump
2. Water pump
3. Generator
4. A/C compressor
5. Crankshaft pulley
6. Auto tensionerREPLACING SPARK PLUGS
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 re-
move the spark plugs. An incorrect socket
can damage the spark plugs.
QR25DE engine
WDI0192WDI0193
SPARK PLUGS
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If you wax the surface of the hood, be careful not
to let wax get into the washer nozzle
s1. This may
cause clogging or improper windshield washer
operation. If wax gets into the nozzle, remove it
with a needle or small pin
s2.
CHECKING PARKING BRAKE
From the released position, pull the parking brake
lever up slowly and firmly. If the number of clicks is
out of the range listed, see a NISSAN dealer.
c6 - 7 clicks under pulling force of 44 lb (196
N) .
CHECKING BRAKE PEDAL
With the engine running, check the distanceA
between the upper surface of the pedal and the
metal floor. If it is out of the range shown, see a
NISSAN dealer.
Distance A: under depressing force of 110
lb (490 N)
Automatic
TransmissionManual
Transmission
3 1/2 in (90 mm) or more
WDI0195
WDI0196WDI0197
PARKING BRAKE AND BRAKE PEDAL
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Self-adjusting brakes
Your vehicle is equipped with self-adjusting
brakes.
The front (and rear, if so equipped) disc-type
brakes self-adjust every time the brake pedal is
applied. The rear drum-type brakes also self-
adjust every time the brake pedal is applied.
If the brake pedal goes down farther than normal,
it may be due to a lack of adjustment of the rear
drum brakes. To adjust, apply the parking brake
several times.
WARNING
See a NISSAN dealer for a brake system
check if the brake pedal height does not
return to normal.
Brake pad wear indicators
The disc brake pads on your vehicle have audible
wear indicators. When a brake pad requires re-
placement, a high pitched scraping or screech-
ing 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, occa-
sional brake squeak, squeal or other noise maybe heard. Occasional brake noise during light to
moderate stops is normal and does not affect the
function or performance of the brake system.
The rear drum brakes (if so equipped) do not
have audible wear indicators. Should you ever
hear an unusually loud noise from the rear drum
brakes, have them inspected as soon as possible
by a NISSAN dealer.
Proper brake inspection intervals should
be followed.For more information regarding
brake inspections, see the appropriate mainte-
nance schedule information in the “NISSAN Ser-
vice and Maintenance Guide”.
BRAKE BOOSTER
Check the brake booster function as follows:
1. With the engine off, press and release the
brake pedal several times. When brake
pedal movement (distance of travel) remains
the same from one pedal application to the
next, continue on to the next step.
2. While depressing the brake pedal, start the
engine. The pedal height should drop a little.
3. With the brake pedal depressed, stop the
engine. Keep the pedal depressed for about
30 seconds. The pedal height should not
change.4. Run the engine for one minute without de-
pressing the brake pedal, then turn it off.
Depress the brake pedal several times. The
pedal travel distance will decrease gradually
with each depression as the vacuum is re-
leased from the booster.
If the brakes do not operate properly, have the
brakes checked by a NISSAN dealer.
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ENGINE COMPARTMENT
CAUTION
Never use a fuse of a higher amperage
rating than specified on the fuse box
cover. This could damage the electrical
system 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 headlight
switch are OFF.
2. Open the engine hood.3. Remove the fuse box cover by pushing the
tab and lifting the cover up.
4. Remove the fuse with the fuse puller. The
fuse puller is located in the center of the fuse
block in the passenger compartment.
5. If the fuse is open, replace it with a new fuse.
6. If a new fuse also opens, have the electrical
system checked and repaired by a NISSAN
dealer.
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.
WDI0199WDI0200
FUSES
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HEADLIGHTS
The headlight is a semi-sealed beam type which
uses a replaceable headlight (halogen) bulb. A
bulb can be replaced from inside the engine
compartment without removing the headlight as-
sembly.
CAUTION
cHigh pressure halogen gas is sealed
inside the halogen bulb. The bulb may
break if the glass envelope is scratched
or the bulb is dropped.
cWhen handling the bulb, do not touch
the glass envelope.
cDO NOT TOUCH THE BULB
cUse the same number and wattage as
originally installed:
Wattage 65/55Bulb No. HB5/9007*
*: Always check with the Parts Depart-
ment at a NISSAN dealer for the latest
parts information.
cDo 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 per-
formance of the headlight.cAiming is not necessary after replacing
the bulb. When aiming adjustment is
necessary, contact a NISSAN dealer.
WDI0202
LIGHTS
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Octane rating tips
In most parts of North America, you should use
unleaded gasoline with an octane rating of at
least 87 AKI (Anti-Knock Index) number. How-
ever, you may use unleaded gasoline with an
octane rating as low as 85 AKI (Anti-Knock Index)
number in high altitude areas [over 4,000 ft
(1,219 m)] such as: Colorado, Montana, New
Mexico, Utah, Wyoming, northeastern Nevada,
southern Idaho, western South Dakota, western
Nebraska, and the part of Texas which is directly
south of New Mexico.
Using unleaded gasoline with an octane
rating lower than stated above can cause
persistent, heavy “spark knock.” (“Spark
knock” is a metallic rapping noise.) If se-
vere, this can lead to engine damage. If you
detect a persistent 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, have a NISSAN dealer correct the
condition. Failure to correct the condition
is misuse of the vehicle, for which NISSAN
is not responsible.
Incorrect ignition timing may result in spark
knock, after-run and/or overheating, which may
cause excessive fuel consumption or enginedamage. If any of the above symptoms are en-
countered, have your vehicle checked at a
NISSAN dealer.
However, now and then you may notice
light spark knock for a short time while
accelerating 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.
9-4Technical and consumer information
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ENGINE
ModelQG18DE QR25DE
TypeGasoline, 4-cycle, DOHC Gasoline, 4-cycle, DOHC
Cylinder arrangement4-cylinder in-line 4-cylinder in-line
Bore x Stroke in (mm) 3.150 x 3.465 (80. x 88.0) 3.504 x 3.937 (89.0 x 100.0)
Displacement cu in (cm
3) 107.94 (1,769) 151.8 (2488)
Firing order1–3–4–2 1–3–4–2
Idle speed rpm
Ignition timing degree (B.T.D.C.) at idle speed
degree/rpm See the “Emission Control label” on the underside of the hood.
CO percentage at idle speed
[No air]%
Platinum-tipped type Platinum-tipped type
Spark plug Hot PLFR4A-11 *1 PLFR4A-11 *1
Standard PLFR5A-11 *1 PLFR5A-11 *1
Cold PLFR6A-11 *1 PLFR6A-11 *1
Camshaft operationTiming chain Timing chain
Spark plug gap (Nominal) in (mm) 0.043 (1.1) 0.043 (1.1)
Generator belt size0.843 x 32.28, (21.4 x 820)
Width x Length in (mm) 0.843 x 44.09, (21.4 x 1,120)*2 0.843 x 88.46, (21.4 x 2247)
*1: Always check with the Parts Department at a NISSAN dealer for the latest parts information.
*2: With air conditioner
The spark ignition system of this vehicle meets all requirements of the Canadian Interference-Causing Equipment Regulations.
SPECIFICATIONS
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to the vehicle bumper or axle. Be sure to leave
enough slack in the chains to permit turning
corners.
Trailer lights
Trailer lights should comply with federal and/or
local regulations. When wiring the vehicle for
towing, connect the stop and tail light pickup into
the vehicle electrical circuit.
Trailer brakes
If your trailer is equipped with a braking system,
make sure it conforms to federal and/or local
regulations and that it is properly installed.
WARNING
Never connect a trailer brake system di-
rectly to the vehicle brake system.
Pre-towing tips
cBe certain your vehicle maintains a level posi-
tion when a loaded and/or unloaded trailer is
hitched. Do not drive the vehicle if it has an
abnormal nose-up or nose-down condition;
check for improper tongue load, overload,
worn suspension or other possible causes of
either condition.
cAlways secure items in the trailer to prevent
load shift while driving.cBe certain your rear view mirrors conform to all
federal, state or local regulations. If not, install
any mirrors required for towing before driving
the vehicle.
Trailer towing tips
In order to gain skill and an understanding of the
vehicle’s behavior, you should practice turning,
stopping and backing up in an area which is free
from traffic. Steering stability and braking perfor-
mance will be somewhat different than under
normal driving conditions.
cAlways secure items in the trailer to prevent
load shift while driving.
cAvoid abrupt starts, acceleration or stops.
cAvoid sharp turns or lane changes.
cAlways drive your vehicle at a moderate speed.
cAlways block the wheels on both vehicle and
trailer when parking. Parking on a slope is not
recommended; however, if you must do so,
and if your vehicle is equipped with an auto-
matic transmission, first block the wheels and
apply the parking brake, and then move the
transmission shift selector lever into the P
(Park) position. If you move the shift selector
lever to the P (Park) position before blocking
the wheels and applying the parking brake,
transmission damage could occur.cWhen going down a hill, shift into a lower gear
and use the engine braking effect. When go-
ing up a long grade, downshift the transmis-
sion to a lower gear and reduce speed to
reduce chances of engine overloading and/or
overheating. However, for long steep grades,
do not stay in 1st or 2nd gear when driving
above 35 MPH (56 km/h) .
cIf the engine coolant rises to an extremely high
temperature when the air conditioner system
is on, turn off the air conditioner. Coolant heat
can be additionally vented by opening the win-
dows, switching the fan control to high and
setting the temperature control to the HOT
position.
cTrailer towing requires more fuel than normal
circumstances.
cAvoid towing a trailer for your vehicle’s first
500 miles (805 km) .
cHave your vehicle serviced more often than at
intervals specified in the recommended Main-
tenance Schedule in the “NISSAN Service
and Maintenance Guide”.
cWhen making a turn, your trailer wheels will be
closer to the inside of the turn than your vehicle
wheels. To compensate for this, make a larger
than normal turning radius during the turn.
9-16Technical and consumer information
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