1995 NISSAN ALMERA N15 instrument panel

ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION ~

Malfunction IndicatorLamp(MIL)(Cont'd)

DIAGNOSTIC TESTMODE I-BULB CHECK

In this mode, theMALFUNCTION INDICATORLAMPonthe instrument panelshould stayON.If
it
remains
OFF, check thebulb. Refer toEL section ("WARNING LAMPSANDCHIME") orsee EC-370.

DIAGNOSTIC TESTMODE I-MALFUNCTION WARNING
MALFUNCTION INDICATORLAMP
ON
OFF Condition
Engine coolant temperature sensorcircuitmalfunction isdetected, orthe ECM's CPU
is malfunctioning.
No malfunction.

• These Diagnostic TroubleCodeNumbers areclarified inDiagnostic TestMode II(SELF-DIAGNOS-
TIC RESULTS).

DIAGNOSTIC TESTMODE II-SELF-DIAGNOSTIC RESULTS

In this mode, adiagnostic troublecodeisindicated bythe number ofblinks ofthe MALFUNCTION INDI-
CATOR LAMPasshown below.

Example: Diagnostic troublecodeNo.12and No.43

0.6 0.3

ON
1111

OFF ~
0.9 0.3
0.6

--I~
2.1 0.6
0.9
0.3

Unit:second
Diagnostic troublecodeNo.12 Diagnostic
troublecodeNo.43

AEC490
• SELF-DIAG RESULTS.
0

FAILURE DETECTED TIME
NATS MALFUNCTION

0

I
ERASE

II
PRINT

I

SEF288Q

Long
(0.6second) blinkingindicates thenumber often digits, andshort (0.3second) blinkingindicates
the number ofsingle digits.Forexample, themalfunction indicatorlampblinks 4times forabout 2.5
seconds (0.6secx4times) andthen itblinks threetimes forabout 1second (0.3sec x3 times). This
indicates theDTC "43" andrefers tothe malfunction ofthe throttle position sensor.
In this way, allthe detected malfunctions areclassified bytheir diagnostic troublecodenumbers. The
DTC "55" refers tono malfunction. (SeeDIAGNOSTIC TROUBLECODECHART, refertoEC-268.)

HOW TOERASE DIAGNOSTIC TESTMODE II(Self-diagnostic results)

The diagnostic troublecodecanbeerased fromthebackup memory inthe ECM when thediagnostic
test mode ischanged fromDiagnostic TestMode IIto Diagnostic TestMode
I.
(Refer to"HOW TO
SWITCH DIAGNOSTIC TESTMODES" onprevious page.)
• Ifthe battery terminal isdisconnected, thediagnostic troublecodewillbelost from thebackup
memory within24hours.
• Becareful nottoerase thestored memory beforestarting- troublediagnoses.
• Ifthe MIL blinks or"NATS MALFUNCTION" isdisplayed on
"SELF-OIAG RESULTS"screen,perform self-diagnostic
results modewithCONSULT usingNATS program card
(NA TS-E940). RefertoEL section.
• Confirm noself-diagnostic resultsofNATS isdisplayed
before touching "ERASE" in"SELF-DiAG RESULTS"mode
with CONSULT.
• When replacing ECM,inltialisation ofNATS V2.0system and
registration ofall NATS V2.0 Ignition keyIDsmust becar-
ried outwith CONSULT usingNATS program card(NATS-
E940).
Therefore, besure toreceive allkeys from vehicle owner.
Regarding theprocedures ofNATS initialisation andNATS
ignition key
10
registration, refertoCONSULT operation
manual, NATS V2.0.

EC-252

TROUBLEDIAGNOSIS -General Description
Fail-Safe Chart

The ECM enters fail-safe mode,ifany ofthe following DTCsisrecorded duetothe open orshort circuit.

DTC No.
Detected items Engineoperating conditioninfail-safe mode
MIL
12 Massairflow sensor Enginespeedwillnotrise more than2,400 rpmduetothe fuel cut.
circuit
13 Enginecoolant tem-Engine coolant temperature willbedetermined basedonthe time after turning ignition
perature sensorcir-switch "ON"or"START".
cuit ConditionEnginecoolant temperature decided
Just asignition switchisturned ONorStart 30'C(86'F)
More than4minutes afterignition ONorStart 80'C(176'F)
Except asshown above 30
-80'C (86-176'F)
(Depends onthe time)
43 Throttle position
Throttleposition willbedetermined basedonthe injected fuelamount andtheengine
sensor circuit
speed.
Therefore, acceleration willbepoor.
Condition Drivingcondition
When engine i$idling
Normal
When accelerating Pooracceleration

-
Start
signal circuit

If
the ECM always receives astart signal, theECM willjudge thestart signal "OFF"
when engine speedisabove 1,000rpm.
This prevents extraenrichment.
After theengine speedisbelow 200rpm, start-up enrichment willbeallowed untilthe
engine speedreaches 1,000rpm.

-
ECM
Fail-safesystemactivating conditionwhenECMismalfunctioning
The computing functionofthe ECM wasjudged tobe malfunctioning.
When thefail-safe systemactivates (i.e.,ifthe ECM detects amalfunction conditionin
the CPU ofECM), theMALFUNCTION INDICATORLAMPonthe instrument panellightsto
warn thedriver.
Engine control, withfail-safe system,operates whenECMismalfunctioning
When thefail-safe systemisoperating, fuelinjection, ignitiontiming,fuelpump
operation, IACV-AACvalveoperation andcooling fanoperation arecontrolled undercer-
tain limitations.
Operation
Engine speed Enginespeedwillnotrise more than3,000 rpm
Fuel injection
Simultaneousmultiportfuelinjection system
Ignition timing Ignitiontimingisfixed atthe preset valve
Fuel pump Fuel
pump relayis"ON" whenengine isrunning and"OFF" when
engine stalls
IACV-AAC valve
Fullopen
Cooling fans Cooling
fanrelay "ON" (Highspeed condition) whenengine is
running, and"OFF" whenengine stalls
EC-270

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
Heated Oxygen Sensor(H02S)(Cont'd)
DIAGNOSTIC PROCEDURE
• MIXTURE RATIOTEST.
ACCELERATE TO2000
RPM AND HOLD THEN
TOUCH START.
INSPECTION
START

*
NO FAIL
0

II=]

1800 20002200
ij

NEXT
II
START
J

RECORD \ I/

'~/'

- CHECK-

/
......

/ I\
INSPECTION
END

OK
NG
CHECK
HEATED OXYGEN SENSOR
CIRCUIT.

1. Start engine andwarm itup suffi-
ciently.

rF.i\
2.Perform "MIXTURE RATIO

\J!J
TEST"in"FUNCTION TEST"
mode withCONSULT.

OR

rF.i\
2.Make surethat"M/R FIC

\J!J
MNT"in"DATA MONITOR"
mode indicates "RICH"and
"LEAN" periodically more
than 5times during 10 sec-
onds at2,000 rpm.

OR

~ 2.Stop engine andsetECM
~ Diagnostic TestMode II
(Heated oxygensensormoni-
tor).
3. Restart engineandrunitat
about 2,000rpmforabout 2
minutes underno-load.
4. Keep engine speedat2,000
rpm andmake surethatthe
malfunction indicatorlampon
the instrument panelgoeson
and offmore than5times dur-
ing 10seconds.

SEF815L

I

MEC782B

2000rpm

RICH

CMPSoRPM
(REF)
M/R FICMNT

*.

MONITOR
Repairharness orcon-
nectors.

NG
OK
@
SEF089PA
Malfunction
indicator
lamp

~

Heated oxygen '~~
sensor harness connector \

ij
~I 1-''--\
CHECK
INPUTSIGNAL CIRCUIT.
SEF051PA
1.Turn ignition switch"OFF".
'-------------------' 2.Disconnect heatedoxygen sensor
harness connector andECM harness
connector.
3. Check harness continuity between
ECM terminal
@
and terminal
@.
Continuity shouldexist.

4. Check harness continuity between
ECM terminal
@
(orterminal
@)

and ground.

Continuity shouldnotexist.

if OK, check harness forshort.

II
~i5

ECM
-er
CONNECTOR
II

19
~i5

~
MEC735B EC-364

PRECAUTIONS

Observe thefollowing precautions toensure safeandproper
servicing.

Supplemental RestraintSystem(SRS)"AIR
BAG" (DualAirBag System)

The Supplemental RestraintSystem"AirBag" usedalong with
a seat belt,helps toreduce therisk orseverity ofinjury tothe
driver andfront passenger inafrontal collision. TheSupple-
mental Restraint Systemconsists ofair bag modules (located
in the center ofthe steering wheelandonthe instrument panel
on the passenger side),adiagnosis sensorunit,warning lamp,
wiring harness andspiral cable. Information necessarytoser-
vice thesystem safelyisincluded inthe RSsection ofthis Ser-
vice Manual.
WARNING:
• To avoid rendering theSRS inoperative, whichcould
increase therisk ofpersonal injuryordeath inthe event of
a collision whichwould resultinair bag inflation, allmain-
tenance mustbeperformed byan authorized NISSAN
dealer.
• Improper maintenance, includingincorrectremovaland
installation ofthe SRS, canlead topersonal injurycaused
by unintentional activationofthe system.
• Donot use electrical testequipment onany circuit related
to the SRS unless instructed tointhis Service Manual. SRS
wiring harnesses arecovered withyellow insulation either
just before theharness connectors orfor the complete
harness, foreasy identification.

Supplemental RestraintSystem(SRS)"AIR
BAG" (Single AirBag System)

The Supplemental RestraintSystem"AirBag" andused along
with aseat belt, helps toreduce therisk orseverity ofinjury to
the driver inafrontal collision. TheSupplemental Restraint
System consists ofan air bag module (located inthe center of
the steering wheel),adiagnosis sensorunit,warning lamp,
wiring harness andspiral cable. Information necessarytoser-
vice thesystem safelyisincluded inthe RSsection ofthis Ser-
vice Manual.
WARNING:
• To avoid rendering theSRS inoperative, whichcould
increase therisk ofpersonal injuryordeath inthe event of
a collision whichwould resultinair bag inflation, allmain-
tenance mustbeperformed byan authorized NISSAN
dealer.
• Improper maintenance, includingincorrectremovaland
installation ofthe SRS, canlead topersonal injurycaused
by unintentional activationofthe system.

GI-2

SGI916PRECAUTIONS

• Donot use electrical testequipment onany circuit related •
to the SRS unless instructed tointhis Service Manual.

Precautions forNATS V2.0(ForGasoline Engine
Model)
NATS (Nissan Anti-Theft System)

NATS V2.0willimmobilize theengine ifsomeone triestostart
it without theregistered keyofNATS V2.0.
Both ofthe originally suppliedignitionkeyIDshave been NATS
registered.
The NATS security indicator islocated onthe instrument panel.
The indicator blinkswhentheignition switchisin "OFF" or
"ACC" position. Therefore, NATSwarns outsiders thatthevehi-
cle isequipped withtheanti-theft system.
• When NATSdetects trouble, themalfunction indicatorlamp
(MIL) blinks.
This blinking indicates thattheanti-theft isnot functioning,
so prompt service isrequired.
• When servicing NATS(trouble diagnoses, systeminitialisa-
tion andadditional registration ofother NATS ignition key
IDs), CONSULT hardwareandCONSULT NATSsoftware is
necessary.
Regarding theprocedures ofNATS initialisation andNATS
ignition key
10
registration, refertoCONSULT operation
manual, NATSV2.0.

Therefore, CONSULTNATSsoftware (program cardandoper-
ation manual) mustbekept strictly confidential tomaintain the
integrity ofthe anti-theft function.

• When servicing NATSV2.0(trouble diagnoses, systemini-
tial isation andadditional registration ofother NATS ignition
key IDs),
it
may benecessary tore-register originalkey
identification. Therefore,besure toreceive allkeys from
vehicle owner.
A maximum offour keyIDscan beregistered intoNATS.
• When failing tostart theengine first-time usingthekey of
NATS V2.0,startasfollows.
(1) Turn ignition keyto"OFF".
(2) Wait approx. 5seconds.
(3) Turn ignition keyto"START" againwhilekeeping the
key apart fromanyothers onkey-chain.

SGI285 General
Precautions

• Donot operate theengine foranextended periodoftime
without properexhaust ventilation.
Keep thework areawellventilated andfree ofany flamma-
ble materials. Specialcareshould betaken whenhandling
any flammable orpoisonous materials,suchasgasoline,
refrigerant gas,etc.When working inapit orother enclosed
area, besure toproperly ventilate thearea before working
with hazardous materials.
Do not smoke whileworking onthe vehicle.

GI-3

HOWTOPERFORM EFFICIENT DIAGNOSIS FORANELECTRICAL INCIDENT
Incident Simulation Tests(Cont'd)
Engine compartment

There areseveral reasons avehicle orengine vibration could•
cause anelectrical complaint. Someofthe things tocheck for
are:
• Connectors notfully seated.
• Wiring harness notlong enough andisbeing stressed due
to engine vibrations orrocking.
• Wires laying across brackets ormoving components.
• Loose, dirtyorcorroded groundwires.
• Wires routed tooclose tohot components.
To inspect components underthehood, startbyverifying the
integrity ofground connections. (RefertoGROUND INSPEC-
TION described later.)Firstcheck thatthesystem isproperly
grounded. Thencheck forloose connection by
gently shaking

the wiring orcomponents aspreviously explained. Usingthe
wiring diagrams inspectthewiring forcontinuity.

Behind theinstrument panel

An improperly routedorimproperly clampedharnesscan
become pinchedduringaccessory installation. Vehiclevibra-
tion canaggravate aharness whichisrouted alongabracket
or near ascrew.

Under seating areas

An unclamped orloose harness cancause wiring tobe pinched
by seat components (suchasslide guides) duringvehicle vibra-
tion. Ifthe wiring runsunder seating areas,inspect wirerout-
ing forpossible damageorpinching.

Heating test

Do not heat above 60°C(140°F).

8GI842 HEAT
SENSITIVE

The owner's problem mayoccur during hotweather orafter car
has satforashort time.Insuch cases youwillwant tocheck
for aheat sensitive condition.
To determine ifan electrical component isheat sensitive, heat
the component withaheat gunorequivalent.

Do not heat components above
60°C
(140°F).
Ifincident occurs
while heating theunit, either replace orproperly insulatethe
component.

GI-21

PRECAUTIONSANDPREPARATION
Supplemental RestraintSystem(SRS)"AIR
BAG" (DualAirBag System)

The Supplemental RestraintSystem"AirBag" usedalong withaseat belt,helps toreduce therisk or
severity ofinjury tothe driver andfront passenger inafrontal collision. TheSupplemental Restraint
System consists ofair bag modules (locatedinthe center ofthe steering wheelandonthe instrument
panel onthe passenger side),adiagnosis sensorunit,warning lamp,wiring harness andspiral cable.
Information necessarytoservice thesystem safelyisincluded inthe
RSsection
ofthis Service Manual.

WARNING:
• Toavoid rendering theSRS inoperative, whichcouldincrease therisk ofpersonal injuryordeath
in the event ofacollision whichwould resultinair bag inflation, allmaintenance mustbeperformed
by an authorized NISSANdealer.
• Improper maintenance, includingincorrectremovalandinstallation ofthe SRS, canlead topersonal
injury caused byunintentional activationofthe system.
• Donot use electrical testequipment onany circuit related tothe SRS unless instructed tointhis
Service Manual. SRSwiring harnesses arecovered withyellow insulation eitherjustbefore the
harness connectors orfor the complete harness,foreasy identification.
Supplemental RestraintSystem(SRS)"AIR
BAG" (Single AirBag System)

The Supplemental RestraintSystem"AirBag" andused along withaseat belt,helps toreduce therisk
or severity ofinjury tothe driver inafrontal collision. TheSupplemental RestraintSystemconsists of
an air bag module (located inthe center ofthe steering wheel),adiagnosis sensorunit,warning lamp,
wiring harness andspiral cable. Information necessarytoservice thesystem safelyisincluded inthe

RS section
ofthis Service Manual.

WARNING: • Toavoid rendering theSRS inoperative, whichcouldincrease therisk ofpersonal injuryordeath
in the event ofacollision whichwould resultinair bag inflation, allmaintenance mustbeperformed
by anauthorized NISSANdealer.
• Improper maintenance, includingincorrectremovalandinstallation ofthe SRS, canlead topersonal
injury caused byunintentional activationofthe system.
• Donot use electrical testequipment onany circuit related tothe SRS unless instructed tointhis
Service Manual.
HA-2

TROUBLEDIAGNOSES
Preliminary Check
PRELIMINARY CHECK1

Ale
does notblow coldair.
DOESAIRFLOW FROM VENTS?
Condition
• Engine running atoperating tem-
perature .
• Ignition switch,AICswitch, and
fan switch areON.
• Mode control knobisin VENT
mode andtemperature control
knob isinfull cold position.
Yes IS
BLOWER MOTOROPERATING
NORMALLY?
Yes
CHECKBLOWER
MOTOR OPERATION.
Go toDiagnostic Pro-
cedure 1.(HA-50)
CHECK COMPRESSOR BELTTEN-
SION. Refer to"Checking DriveBelts" in
MA section.
CHECK REFRIGERANT.
Connect manifold gaugethen
check system pressure.
Refer toPerformance Chart.(HA-

26)

NG CHECK
THERMO CONTROL AMP.
OPERATION.
Refer toElectrical Components
Inspection. (HA-63)
CHECK
FOREVAPORATOR COIL
FREEZE UP.
Remove intakeunit.Check ifevap-
orator freezes.
NG OK
(Freeze up.) (Doesnot
freeze up.)
CHECK VENTILATOR
DUCT FORAIR
LEAKS.
OK
Go toPerformance
Test Diagnoses. (HA-

24)
NG
CHECK
REFRIGERATION CYCLE
PRESSURE WITHMANIFOLD
GAUGE CONNECTED.
Refer toPerformance Chart.(HA-
26) OK
CHECK
COMPRESSOR OPERA-
TION.
OK
OK NG
Adjust orreplace
compressor belt.
Refer toMA section
("ENGINE
MAINTENANCE").
CHECKFORREFRIG-
ERANT LEAKS CHECK
WATER COCKOPERA-
TION.
Warm upengine beforechecking.
Refer toHA-64.
NG

Adjust orreplace watercock.
OK
Go toDiagnostic Procedure3.
(HA-54) CHECK
TEMPERATURE CONTROL
CABLE.
Refer toControl Linkage Adjust-
ment. (HA-64) NG
Adjust temperature controlcable.
OK
VISUALLY INSPECTAIRMIX
DOOR.
Access byremoving instrument
panel. NG
Replace airmix door.
OK
CHECK THERMO CONTROL AMP.
OPERATION. Refer toElectrical Components
Inspection. (HA-63)
HA-20