2001 NISSAN ALMERA o2 sensor

SEF122U
Checking Water in Fuel Filter Sensor (where
fitted)
NJFE00251. Remove the connector from filter and water in fuel filter sen-
sor.
2. Turn the key switch ªONº. Lift the float to ensure that the
warning lamp turns on.
Water in fuel filter sensor tightening torque:
: 3.9 - 5.9 N´m (0.4 - 0.6 kg-m, 35 - 52 in-lb)
Discard the old O-ring and replace it with a new one.
Removal and InstallationNJFE0015WARNING:
When replacing fuel line parts, be sure to observe the following.
+Put a ªCAUTION: FLAMMABLEº sign in workshop.
+Be sure to furnish workshop with a CO
2fire extinguisher.
+Do not smoke while servicing fuel system. Keep open flames and sparks away from work area.
CAUTION:
+Before removing fuel line parts, carry out the following procedures:
a) Put drained fuel in an explosion-proof container and put the lid on securely.
b) Disconnect battery ground cable.
+Always replace O-ring and clamps with new ones.
+Do not kink or twist tubes when they are being installed.
+Do not tighten hose clamps excessively to avoid damaging hoses.
+After installing tubes, run engine and check for fuel leaks at connections.
FUEL SYSTEMYD
Checking Water in Fuel Filter Sensor (where fitted)
FE-22

SFE561AB
SFE658AA
After connecting quick connector, make sure the connection is
firmly made using the following method.
+Pull on the fuel tube and connector to make sure they are firmly
connected.
+Start the engine, increase engine speed and verify that there
are no leaks.
Fuel Level Sensor UnitNJFE0032
SFE645A
FUEL SYSTEMYD
Fuel Tank (Cont'd)
FE-29

JFE613A
REMOVALNJFE0032S01For SedanNJFE0032S01011. Disconnect battery ground cable.
2. Open fuel filler lid and filler cap.
3. Remove rear seat cushion. Refer to BT-60, ªRemoval and
Installationº.
4. Remove inspection hole cover under the rear seat.
SFE600A
5. Disconnect electrical connector.
6. Disconnect the quick connectors.
+For disconnect of quick connectors, refer to step 7. of ªFuel
Tank Removalº.
7. Remove the six screws.
CAUTION:
Use genuine bolts only when fixing retainer.
8. Remove retainer.
SFE646A
9. Pull out the fuel level sensor unit.
+Do not damage the arm of the fuel level sensor unit.
JFE613A
For HatchbackNJFE0032S01021. Disconnect battery ground cable.
2. Open fuel filler lid and filler cap.
3. Remove rear seat cushion. Refer to BT-60, ªRemoval and
Installationº.
4. Remove inspection hole cover under the rear seat.
SFE639A
5. Disconnect electrical connector.
6. Disconnect the quick connectors.
+For disconnect of quick connectors, refer to step 7. of ªFuel
Tank Removalº.
FUEL SYSTEMYD
Fuel Level Sensor Unit (Cont'd)
FE-30

SFE376A
7. Remove lock ring using a lock ring socket (SST).
SFE648AA
8. Pull out the fuel level sensor unit and fuel pump.
+Do not damage the arm of the fuel level sensor unit.
INSTALLATIONNJFE0032S02Installation is in reverse order of removal.
FUEL SYSTEMYD
Fuel Level Sensor Unit (Cont'd)
FE-31

PrecautionsNJGI0001Observe the following precautions to ensure safe and proper
servicing. These precautions are not described in each indi-
vidual section.
SGI646
PRECAUTIONS FOR SUPPLEMENTAL RESTRAINT
SYSTEM (SRS) ªAIR BAGº AND ªSEAT BELT
PRE-TENSIONERº
NJGI0001S01The Supplemental Restraint System such as ªAIR BAGº and ªSEAT
BELT PRE-TENSIONERº used along with a seat belt, helps to
reduce the risk or severity of injury to the driver and front passen-
ger for certain types of collision. The SRS system composition
which is available to NISSAN MODEL N16 is as follows (The com-
position varies according to the destination and optional equip-
ment.):
+For a frontal collision
The Supplemental Restraint System consists of driver air bag
module (located in the center of the steering wheel), front pas-
senger air bag module (located on the instrument panel on
passenger side), front seat belt pre-tensioners, a diagnoses
sensor unit, warning lamp, wiring harness and spiral cable.
+For a side collision
The Supplemental Restraint System consists of front side air
bag module (located in the outer side of front seat), side air bag
(satellite) sensor, diagnoses sensor unit (one of components of
air bags for a frontal collision), wiring harness, warning lamp
(one of components of air bags for a frontal collision).
Information necessary to service the system safely is included in
theRS sectionof this Service Manual.
WARNING:
+To avoid rendering the SRS inoperative, which could
increase the risk of personal injury or death in the event
of a collision which would result in air bag inflation, all
maintenance should be performed by an authorized
NISSAN dealer.
+Improper maintenance, including incorrect removal and
installation of the SRS, can lead to personal injury caused
by unintentional activation of the system. For removal of
Spiral Cable and Air Bag Module, see the RS section.
+Do not use electrical test equipment on any circuit related
to the SRS unless instructed to in this Service Manual.
SRS wiring harnesses can be identified by yellow harness
connector.
PRECAUTIONS FOR NATS (NISSAN ANTI-THEFT
SYSTEM)
NJGI0001S02NATS will immobilize the engine if someone tries to start it without
the registered key of NATS.
Both of the originally supplied ignition key IDs have been NATS
registered.
The security indicator is located on the instrument panel or in the
PRECAUTIONS
Precautions
GI-3

Do not attempt to top off the fuel tank after the fuel pump nozzle
shuts off automatically. Continued refueling may cause fuel
overflow, resulting in fuel spray and possibly a fire.
WARNING:
To prevent ECM from storing the diagnostic trouble codes, do
not carelessly disconnect the harness connectors which are
related to the engine control system and TCM (Transmission
Control Module) system. The connectors should be discon-
nected only when working according to the WORK FLOW of
TROUBLE DIAGNOSES in EC and AT sections.
SGI787
PRECAUTIONS FOR MULTIPORT FUEL INJECTION
SYSTEM OR ENGINE CONTROL SYSTEM
NJGI0001S04+Before connecting or disconnecting any harness connector for
the multiport fuel injection system or ECM:
Turn ignition switch to ªOFFº position.
Disconnect negative battery terminal.
Otherwise, there may be damage to ECM.
+Before disconnecting pressurized fuel line from fuel pump to
injectors, be sure to release fuel pressure.
+Be careful not to jar components such as ECM and mass air
flow sensor.
PRECAUTIONS FOR THREE WAY CATALYSTNJGI0001S05If a large amount of unburned fuel flows into the catalyst, the cata-
lyst temperature will be excessively high. To prevent this, follow the
instructions below:
+Use unleaded gasoline only. Leaded gasoline will seriously
damage the three way catalyst.
+When checking for ignition spark or measuring engine
compression, make tests quickly and only when necessary.
+Do not run engine when the fuel tank level is low, otherwise the
engine may misfire, causing damage to the catalyst.
Do not place the vehicle on flammable material. Keep flammable
material off the exhaust pipe and the three way catalyst.
SMA019D
PRECAUTIONS FOR HOSESNJGI0001S06Hose Removal and InstallationNJGI0001S0601+To prevent damage to rubber hose, do not pry off rubber hose
with tapered tool or screwdriver.
PRECAUTIONS
Precautions (Cont'd)
GI-6

Incident Simulation TestsNJGI0005S02INTRODUCTIONNJGI0005S0201Sometimes the symptom is not present when the vehicle is brought
in for service. If possible, re-create the conditions present at the
time of the incident. Doing so may help avoid a No Trouble Found
Diagnoses. The following section illustrates ways to simulate the
conditions/environment under which the owner experiences an
electrical incident.
The section is broken into the six following topics:
+Vehicle vibration
+Heat sensitive
+Freezing
+Water intrusion
+Electrical load
+Cold or hot start up
Get a thorough description of the incident from the customer. It is
important for simulating the conditions of the problem.
VEHICLE VIBRATIONNJGI0005S0202The problem may occur or become worse while driving on a rough
road or when engine is vibrating (idle with A/C on). In such a case,
you will want to check for a vibration related condition. Refer to the
illustration below.
Connectors & Harness
Determine which connectors and wiring harness would affect the
electrical system you are inspecting.Gentlyshake each connec-
tor and harness while monitoring the system for the incident you
are trying to duplicate. This test may indicate a loose or poor elec-
trical connection.
Hint
Connectors can be exposed to moisture. It is possible to get a thin
film of corrosion on the connector terminals. A visual inspection
may not reveal this without disconnecting the connector. If the
problem occurs intermittently, perhaps the problem is caused by
corrosion. It is a good idea to disconnect, inspect and clean the
terminals on related connectors in the system.
Sensors & Relays
Gentlyapply a slight vibration to sensors and relays in the system
you are inspecting.
This test may indicate a loose or poorly mounted sensor or relay.
SGI839
HOW TO PERFORM EFFICIENT DIAGNOSES FOR AN ELECTRICAL INCIDENT
Incident Simulation Tests
GI-22

NJGI0011
ISO 15031-2 Terminology ListNJGI0011S01All emission related terms used in this publication in accordance with ISO 15031-2 are listed. Accordingly, new
terms, new acronyms/abbreviations and old terms are listed in the following chart.
***: Not applicable
NEW TERMNEW ACRONYM /
ABBREVIATIONOLD TERM
Air cleaner ACL Air cleaner
Barometric pressure sensor BARO sensor ***
Barometric pressure sensor-BCDD BAROS-BCDD BCDD
Camshaft position CMP ***
Camshaft position sensor CMPS Crank angle sensor
Canister *** Canister
Carburetor CARB Carburetor
Charge air cooler CAC Intercooler
Closed loop CL Closed loop
Closed throttle position switch CTP switch Idle switch
Clutch pedal position switch CPP switch Clutch switch
Continuous fuel injection system CFI system ***
Continuous trap oxidizer system CTOX system ***
Crankshaft position CKP ***
Crankshaft position sensor CKPS ***
Data link connector DLC Diagnostic connector for CONSULT
Diagnostic test mode DTM Diagnostic mode
Diagnostic test mode selector DTM selector Diagnostic mode selector
Diagnostic test mode I DTM I Mode I
Diagnostic test mode II DTM II Mode II
Diagnostic trouble code DTC Malfunction code
Direct fuel injection system DFI system ***
Distributor ignition system DI system Ignition timing control
Early fuel evaporation-mixture heater EFE-mixture heater Mixture heater
Early fuel evaporation system EFE system Mixture heater control
Electrically erasable programmable read
only memoryEEPROM ***
Electronic ignition system EI system Ignition timing control
Engine control EC ***
Engine control module ECM ECCS control unit
Engine coolant temperature ECT Engine temperature
Engine coolant temperature sensor ECTS Engine temperature sensor
Engine modification EM ***
Engine speed RPM Engine speed
ISO 15031-2 TERMINOLOGY LIST
ISO 15031-2 Terminology List
GI-50