NISSAN ALMERA 2001 Service Manual

SGI364
CONNECTOR SYMBOLS=NJGI0003S0201Most of connector symbols in wiring diagrams are shown from the
terminal side.
+Connector symbols shown from the terminal side are enclosed
by a single line and followed by the direction mark.
+Connector symbols shown from the harness side are enclosed
by a double line and followed by the direction mark.
+Certain systems and components, especially those related to
OBD, may use a new style slide-locking type harness connec-
tor. For description and how to disconnect, refer to EL-6, ªHAR-
NESS CONNECTORº.
SGI363
+Male and female terminals
Connector guides for male terminals are shown in black and
female terminals in white in wiring diagrams.
HOW TO READ WIRING DIAGRAMS
Description (Cont'd)
GI-15

AGI070
HARNESS INDICATIONNJGI0003S0202+Letter designations next to test meter probe indicate harness
(connector) wire color.
+Connector numbers in a single circle M33 indicate harness
connectors.
COMPONENT INDICATIONNJGI0003S0203+Connector numbers in a double circle F211 indicate compo-
nent connectors.
SGI860
SWITCH POSITIONSNJGI0003S0204Switches are shown in wiring diagrams as if the vehicle is in the
ªnormalº condition.
A vehicle is in the ªnormalº condition when:
+ignition switch is ªOFFº,
+doors, hood and trunk lid/back door are closed,
+pedals are not depressed, and
+parking brake is released.
HOW TO READ WIRING DIAGRAMS
Description (Cont'd)
GI-16

SGI862-A
DETECTABLE LINES AND NON-DETECTABLE LINES=NJGI0003S0205In some wiring diagrams, two kinds of lines, representing wires,
with different weight are used.
+A line with regular weight (wider line) represents a ªdetectable
line for DTC (Diagnostic Trouble Code)º. A ªdetectable line for
DTCº is a circuit in which ECM can detect its malfunctions with
the on board diagnostic system.
+A line with less weight (thinner line) represents a ªnon-detect-
able line for DTCº. A ªnon-detectable line for DTCº is a circuit
in which ECM cannot detect its malfunctions with the on board
diagnostic system.
HOW TO READ WIRING DIAGRAMS
Description (Cont'd)
GI-17

MULTIPLE SWITCH=NJGI0003S0206The continuity of multiple switch is described in two ways as shown
below.
+The switch chart is used in schematic diagrams.
+The switch diagram is used in wiring diagrams.
SGI875
HOW TO READ WIRING DIAGRAMS
Description (Cont'd)
GI-18

REFERENCE AREA=NJGI0003S0207The Reference Area of the wiring diagram contains references to
additional electrical reference pages at the end of the manual. If
connector numbers and titles are shown in the Reference Area of
the wiring diagram, these connector symbols are not shown in the
Connector Area.
SGI092A
Super multiple junction (SMJ)
In a wiring diagram, the SMJ connectors include a letter of the
alphabet in the terminal number.
SMJ connector numbers are shown in the Reference Area of the
wiring diagram. SMJ terminal arrangement can be found on the
electrical reference pages at the end of the manual. For terminal
arrangement of these connectors, refer to the ªSUPER MULTIPLE
JUNCTION (SMJ)º electrical reference page at the end of the
HOW TO READ WIRING DIAGRAMS
Description (Cont'd)
GI-19

manual.
Fuse block Ð Junction box (J/B)
Fuse block Ð Junction box (J/B) connector number is shown in the
Reference Area of the wiring diagram. For connector terminal and
fuse arrangement, refer to the ªFUSE BLOCK Ð Junction Box
(J/B)º electrical reference page at the end of the manual.
Fuse and fusible link box
For fuse arrangement in the fuse and fusible link box, refer to the
ªFUSE AND FUSIBLE LINK BOXº electrical reference page at the
end of the manual.
Electrical units
Electrical unit connector symbols are shown in the Connector Area
of the wiring diagram.
However, when there is not enough space to show the connector
terminal arrangement in the Connector Area of the wiring diagram,
the electrical unit connector number is shown in the Reference
Area of the wiring diagram. For electrical unit connector terminal
arrangement, refer to the ªELECTRICAL UNITSº electrical refer-
ence page at the end of the manual. Most of the electrical unit
connectors on this page are shown from the harness side of the
connector.
Joint connector
Joint connector symbols are shown in the connector area of the
wiring diagram. For connector internal wiring layout and joint con-
nector terminal arrangement, refer to the ªJOINT CONNECTOR
(J/C)º electrical reference page at the end of the manual.
HOW TO READ WIRING DIAGRAMS
Description (Cont'd)
GI-20

NJGI0005
Work FlowNJGI0005S01
SGI838
STEP DESCRIPTION
STEP 1 Get detailed information about the conditions and the environment when the incident occurred.
The following are key pieces of information required to make a good analysis:
WHATVehicle Model, Engine, Transmission and the System (i.e. Radio).
WHENDate, Time of Day, Weather Conditions, Frequency.
WHERERoad Conditions, Altitude and Traffic Situation.
HOWSystem Symptoms, Operating Conditions (Other Components Interaction).
Service History and if any After Market Accessories have been installed.
STEP 2 Operate the system, road test if necessary.
Verify the parameter of the incident.
If the problem can not be duplicated, refer to ªIncident Simulation Testsº next page.
STEP 3 Get the proper diagnoses materials together including:
POWER SUPPLY ROUTING
System Operation Descriptions
Applicable Service Manual Sections
Check for any Service Bulletin.
Identify where to begin diagnoses based upon your knowledge of the system operation and the cus-
tomer comments.
STEP 4 Inspect the system for mechanical binding, loose connectors or wiring damage.
Determine which circuits and components are involved and diagnose using the Power Supply Routing
and Harness Layouts.
STEP 5 Repair or replace the incident circuit or component.
STEP 6 Operate the system in all modes. Verify the system works properly under all conditions. Make sure you
have not inadvertently created a new incident during your diagnoses or repair steps.
HOW TO PERFORM EFFICIENT DIAGNOSES FOR AN ELECTRICAL INCIDENT
Work Flow
GI-21

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

Engine Compartment
There are several reasons a vehicle or engine vibration could
cause an electrical complaint. Some of the things to check for are:
+Connectors not fully seated.
+Wiring harness not long enough and is being stressed due to
engine vibrations or rocking.
+Wires laying across brackets or moving components.
+Loose, dirty or corroded ground wires.
+Wires routed too close to hot components.
To inspect components under the hood, start by verifying the integ-
rity of ground connections. (Refer to GROUND INSPECTION
described later.) First check that the system is properly grounded.
Then check for loose connection bygently shakingthe wiring or
components as previously explained. Using the wiring diagrams
inspect the wiring for continuity.
Behind The Instrument Panel
An improperly routed or improperly clamped harness can become
pinched during accessory installation. Vehicle vibration can aggra-
vate a harness which is routed along a bracket or near a screw.
Under Seating Areas
An unclamped or loose harness can cause wiring to be pinched by
seat components (such as slide guides) during vehicle vibration. If
the wiring runs under seating areas, inspect wire routing for pos-
sible damage or pinching.
SGI842
HEAT SENSITIVENJGI0005S0203The owner's problem may occur during hot weather or after car has
sat for a short time. In such cases you will want to check for a heat
sensitive condition.
To determine if an electrical component is heat sensitive, heat the
component with a heat gun or equivalent.
Do not heat components above 60ÉC (140ÉF).If incident occurs
while heating the unit, either replace or properly insulate the com-
ponent.
SGI843
FREEZINGNJGI0005S0204The customer may indicate the incident goes away after the car
warms up (winter time). The cause could be related to water freez-
ing somewhere in the wiring/electrical system.
There are two methods to check for this. The first is to arrange for
the owner to leave his car overnight. Make sure it will get cold
enough to demonstrate his complaint. Leave the car parked out-
side overnight. In the morning, do a quick and thorough diagnoses
of those electrical components which could be affected.
HOW TO PERFORM EFFICIENT DIAGNOSES FOR AN ELECTRICAL INCIDENT
Incident Simulation Tests (Cont'd)
GI-23

The second method is to put the suspect component into a freezer
long enough for any water to freeze. Reinstall the part into the car
and check for the reoccurrence of the incident. If it occurs, repair
or replace the component.
SGI844
WATER INTRUSIONNJGI0005S0205The incident may occur only during high humidity or in rainy/snowy
weather. In such cases the incident could be caused by water
intrusion on an electrical part. This can be simulated by soaking the
car or running it through a car wash.
Do not spray water directly on any electrical components.
SGI845
ELECTRICAL LOADNJGI0005S0206The incident may be electrical load sensitive. Perform diagnoses
with all accessories (including A/C, rear window defogger, radio,
fog lamps) turned on.
COLD OR HOT START UPNJGI0005S0207On some occasions an electrical incident may occur only when the
car is started cold. Or it may occur when the car is restarted hot
shortly after being turned off. In these cases you may have to keep
the car overnight to make a proper diagnoses.
Circuit InspectionNJGI0005S03INTRODUCTIONNJGI0005S0301In general, testing electrical circuits is an easy task if it is
approached in a logical and organized method. Before beginning
it is important to have all available information on the system to be
tested. Also, get a thorough understanding of system operation.
Then you will be able to use the appropriate equipment and follow
the correct test procedure.
You may have to simulate vehicle vibrations while testing electrical
components.Gently shakethe wiring harness or electrical com-
ponent to do this.
OPEN A circuit is open when there is no continuity through a section of
the circuit.
SHORT There are two types of shorts.
+SHORT CIRCUIT When a circuit contacts another circuit
and causes the normal resistance to
change.
+SHORT TO GROUND When a circuit contacts a ground source
and grounds the circuit.
HOW TO PERFORM EFFICIENT DIAGNOSES FOR AN ELECTRICAL INCIDENT
Incident Simulation Tests (Cont'd)
GI-24