1995 NISSAN ALMERA N15 Service Manual

ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Conl'd)

Monitored item ECM
Main
[Unit] input
signals Description
Remarks
signals
AIR COND SIG •Indicates [ON/OFF] conditionofthe
[ON/OFF]
00
air
conditioner switchasdetermined
by the airconditioning signal.
PIN POSI SW

00
•
Indicates [ON/OFF] conditionfromthe
[ON/OFF] park/neutralpositionswitchsignal.
PW/ST SIGNAL •Indicates [ON/OFF] conditionofthe
[ON/OFF]
00
power
steering oilpressure switch
determined bythe power steering oil
pressure signal.
INJ PULSE [msec]

0
•
Indicates theactual fuelinjection •
When theengine isstopped, acertain
pulse widthcompensated byECM computedvalueisindicated.
according tothe input signals.
IGN TIMING [BTDC]

0
•
Indicates theignition timingcomputed
by ECM according tothe input sig-
nals.
IACV-AACIV
[%]
•Indicates theidle aircontrol valve

0
(AAC
valve) control valuecomputed
by ECM according tothe input sig-
nals.
A/F ALPHA [%J •Indicates themean valueofthe air- •When theengine isstopped, acertain

0
fuel
ratio feedback correction factor valueisindicated.
per cycle. •This dataalsoincludes thedata for
the air-fuel ratiolearning control.
AIR COND RLY •Indicates theairconditioner relay
[ON/OFF]
0
control
condition (determined byECM
according tothe input signal).
FUEL PUMP RLY •Indicates thefuel pump relaycontrol
[ON/OFFJ
0
condition
determined byECM accord-
ing tothe input signals.
COOLING FAN
•Indicates thecontrol condition ofthe
[HI/LOW/OFFJ coolingfans(determined byECM

0
according
tothe input signal).
HI ...High speed operation
LOW ...Low speed operation
OFF ...Stopped
EGRC SOLIV •Indicates thecontrol condition ofthe
[ON/OFFJ EGR
valve
&
EVAP canister Purge
control solenoid valve(determined by

0
ECM
according tothe input signal).
ON ...EGR andEVAP canister purge
operation cut-off
OFF ...EGR andEVAP canister purge
operation notcut-off
VOLTAGE •Voltage measured bythe voltage
[V] probe.
PULSE •Pulse width, frequency orduty cycle •Only "#"isdisplayed ifitem is
[msec] or[Hz] or
measuredbythe pulse probe. unabletobe measured.

[%]
•Figures with"#"s aretemporary
ones. Theyarethesame figures as
an actual pieceofdata which wasjust
previously measured.

EC-258

ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Conl'd)
ACTIVE TESTMODE

TEST ITEM CONDITION JUDGEMENTCHECKITEM(REMEDY)
• Engine: Returntothe original
•Harness andconnector
FUEL INJECTION trouble
condition
Iftrouble symptom disappears,
•Fuel injectors
• Change theamount offuel
seeCHECK ITEM.
•Heated oxygen sensor
injection usingCONSULT .
• Engine: Afterwarming up,idle
IACV-AACIV the
engine.
Enginespeedchanges according •Harness andconnector
OPENING •
Change theIACV-AAC valve
tothe opening percent. •
IACV-AAC valve
opening percentusingCON-
SULT.
• Engine: Returntothe original
•Harness andconnector
ENG COOLANT trouble
condition
Iftrouble symptom disappears, •
Engine coolant temperature
• Change theengine coolant
.

TEMP see
CHECK ITEM. sensor
temperature indicationusing
•Fuel injectors
CONSULT .
• Engine: Returntothe original
trouble condition
Iftrouble symptom disappears,
IGNITION TIMING•Timing light:Set •
Adjust initialignition timing
• Retard theignition timingusingsee
CHECK ITEM.
CONSULT.
• Engine: Afterwarming up,idle •
Harness andconnector
the engine. •
Compression
POWER
•
AIC
switch "OFF"
Enginerunsrough ordies. •
Injectors
BALANCE •
Shift lever "N" •
Power transistor
• Cut offeach injector signalone •
Spark plugs
at atime using CONSULT . •
Ignition coils
• Ignition switch:ON
•Harness andconnector
COOLING FAN•
Turn thecooling fan"ON" andCooling
fanmoves andstops.
•Cooling fanmotor
"OFF" usingCONSULT .
• Ignition switch:ON(Engine
FUEL PUMP stopped)
Fuelpump relaymakes theoper- •
Harness andconnector
RELAY •
Turn thefuel pump relay"ON"
atingsound. •
Fuel pump relay
and "OFF" usingCONSULT
and listen tooperating sound.
EGRC •
Ignition switch:ON
• Turn solenoid valve"ON"and Solenoid
valvemakes anoperat- •
Harness andconnector
SOLENOID "OFF"withtheCONSULT andingsound. •
Solenoid valve
VALVE listentooperating sound.
SELF-LEARNING •
In this test, thecoefficient ofself-learning controlmixture ratioreturns tothe original coefficient by
CONT touching
"CLEAR" onthe screen.

EC-259
•

ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Conl'd)
FUNCTION TESTMODE

FUNCTION TEST
CONDITION JUDGEMENTCHECKITEM(REMEDY)
ITEM
•Ignition switch:ON
SELF-DIAG (Enginestopped)
Objectivesystem

-

RESULTS •Displays theresults ofon-
board diagnostic system.
• Ignition switch:ON
•Harness andconnector
(Engine stopped)
Throttlevalve:opened OFF
•Throttle position sensor
• Closed throttle position is
•Throttle position sensor
CLOSED THROTTLE testedwhenthrottle is
POSI opened
andclosed fully. adjustment
• Throttle linkage
(Closed throttleposition is
Throttle valve:closed
ON•
Verify operation inDATA
selected bythrottle posi-
MONITORmode.
tion sensor.)
• Ignition switch:ON •
Harness andconnector
• Throttle position sensor
(Engine stopped)
Range(Throttle valvefully •Throttle position sensor
THROTTLE POSI•Throttle position sensor
opened-Throttle valve More
than
adjustment
SEN CKT circuitistested when 3.QV
throttle isopened and fully
closed) •Throttle linkage
• Verify operation inDATA
closed fully.
MONITORmode.
• Ignition switch:ON
•Harness andconnector
(Engine stopped) Out
ofN/P positions OFF
PARK/NEUT POSI•Inhibitor/Neutral position •
Neutral position switchor
SW CKT switch
circuit istested inhibitor
switch
when shiftlever ismanip-
InN/P positions ON•
Linkage orinhibitor switch
ulated . adjustment
• Ignition. switch:ON
•Harness andconnector
(Engine stopped)
•Fuel pump
FUEL PUMP •Fuel pump circuit istested
Thereispressure pulsation onthe fuel
•Fuel pump relay
CIRCUIT bychecking thepulsation feedhose.
in fuel pressure whenfuel •
Fuel filter clogging
tube ispinched . •
Fuel level
• Ignition switch:ON
(Engine stopped)
•Harness andconnector
EGRC SOLIV •
EGR valve
&
EVAP canis-
Thesolenoid valvemakes anoperating •
EGR valve
&
EVAP canis-
CIRCUIT ter
purge control solenoid
soundevery3seconds. terpurge control solenoid
valve circuit istested by

.

valve
checking solenoidvalve
operating noise.
• Ignition switch:ON
COOLING FAN (Engine
stopped)
Thecooling fanrotates andstops every •
Harness andconnector
• Cooling fancircuit is •Cooling fanmotor
CIRCUIT testedwhencoaling fanis3
seconds.
•Cooling fanrelay
rotated.

EC-260

ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Cont'd)

FUNCTION TEST
CONDITION
ITEM JUDGEMENT
CHECKITEM(REMEDY)
• Ignition switch:ON
->

START
• Start signal circuit is
tested whenengine is
started byoperating the
starter. Beforecranking,
START SIGNAL batteryvoltage andengine
Startsignal: OFF
->
ON •
Harness andconnector
CIRCUIT coolanttemperature are
•Ignition switch
displayed. During
cranking, averagebattery
voltage, massairflow
sensor outputvoltage and
cranking speedaredis-
.

played .
• Ignition switch:ON
(Engine running)
Lockedposition ON
•Harness andconnector
PW/ST SIGNAL •
Power steering circuitis
•Power steering oilpres-
CIRCUIT tested
whensteering
sureswitch
wheel isrotated fullyand
•Power steering oilpump
then settoastraight lineNeutral
position OFF
running position.
• Vehicle speedsensor cir-
•Harness andconnector
VEHICLE SPEED cuitistested whenvehicle Vehiclespeedsensor inputsignal is
•Vehicle speedsensor
SEN CKT isrunning ataspeed of10 greater than4km/h (2MPH)
•Electric speedometer
km/h (6MPH) orhigher .
• After warming up,idle the
engine. •Adjust ignition timing(by
• Ignition timingadjustment
movingcrankshaft position
is checked byreading Thetiming lightindicates thesame
IGN TIMING ADJ
ignitiontimingwithatim- valueonthe screen. sensor
ordistributor)
ing light andchecking •
Camshaft positionsensor
whether itagrees with drive
mechanism
specifications. •INJECTION SYS(Injector,
fuel pressure regulator,
harness orconnector)
• Air-fuel ratiofeedback cir- •
IGNITION SYS(Spark
cuit (injection system,igni- plug,
power transistor,
ignition coil,harness or
tion system, vacuum
connector)
MIXTURE RATIO system,
etc.)istested byHeated oxygen sensorCOUNT: More
•VACUUM SYS(Intake air
TEST examining
theheated oxy-than
5times during 10seconds
leaks)
gen sensor outputat2,000
•Heated oxygen sensorcir-
rpm under non-loaded
cuit
state. •Heated oxygen sensor
operation
• Fuel pressure highorlow
• Mass airflow sensor

EC-261
•

ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Cont'd)

FUNCTION TEST
CONDITION JUDGEMENTCHECKITEM(REMEDY)
ITEM
•After warming up,idle the
engine.
• Injector operation ofeach •Injector circuit(Injector,
cylinder isstopped one harness
orconnector)
after another, andresult-
Difference inengine speedisgreater •
Ignition circuit(Spark
ant change inengine rota- plug,
power transistor,
POWER BALANCE
tionisexamined toevalu- than
25rpm before andafter cutting off
ignition coil,harness or
ate combustion ofeach the
injector ofeach cylinder.
connector)
cylinder. (Thisisonly dis- •
Compression
played formodels wherea •
Valve timing
sequential multiportfuel
injection systemisused.)
• After warming up,idle the
•Harness andconnector
engine. •IACV-AAC
valve

• IACV-AAC valvesystem is
Difference inengine speedisgreater •
Air passage restriction
IACV-AACIV testedbydetecting change
than150rpm between whenvalve open- between
airinlet and
SYSTEM inengine speedwhen
ingisat 80% andat20%. IACV-AAC
valve
IACV-AAC valveopening
•IAS (Idle adjusting screw)
is changed to0%,20%
adjustment
and 80%.

EC-262

ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Cont'd)
REAL TIMEDIAGNOSIS INDATA MONITOR MODE

CONSULT hastwo kinds oftriggers andthey canbeselected bytouching "SETTING" in"DATA
MONITOR" mode.
1. "AUTO TRIG"(Automatic trigger):
• The malfunction willbeidentified onthe CONSULT screeninreal time.
In other words, DTCandmalfunction itemwillbedisplayed atthe moment themalfunction is
detected byECM.
DATA MONITOR canbeperformed continuously untilamalfunction isdetected. However, DATA
MONITOR cannotcontinue anylonger afterthemalfunction detection.
2. "MANU TRIG"(Manual trigger):
• DTC andmalfunction itemwillnotbedisplayed automatically onCONSULT screeneventhough a
malfunction isdetected byECM. •
DATA MONITOR canbeperformed continuously eventhough amalfunction isdetected.
Use these triggers asfollows:
1. "AUTO TRIG"
• While trying todetect theDTC byperforming the"DTC CONFIRMATION PROCEDURE",besure to
select to"DATA MONITOR (AUTOTRIG)" mode.Youcanconfirm themalfunction atthe moment
it is detected .
• While narrowing downthepossible causes,CONSULT shouldbeset in"DATA MONITOR (AUTO
TRIG)" mode,especially incase theincident isintermittent.
Inspect thecircuit bygently shaking (ortwisting) suspicious connectors, components andharness
in the "DTC CONFIRMATION PROCEDURE".Themoment amalfunction isfound theDTC willbe
displayed. (RefertoGI section, "Incident Simulation Tests"in"HOW TOPERFORM EFFICIENT
DIAGNOSIS FORANELECTRICAL INCIDENT".)
2. "MANU TRIG"
• Ifthe malfunction isdisplayed assoon as"DATA MONITOR" isselected, resetCONSULT to
"MANU TRIG".Byselecting MANUTRIGyoucan monitor andstore thedata. Thedata canbe
utilized forfurther diagnosis, suchasacomparison withthevalue forthe normal operating con-
dition.

ECM INPUT SIGNALS
HISPEED

AUTO
TRIG

I
~
SELECT MONITOR ITEM

I
MAIN SIGNALS

I
SELECTION FROMMENU

1 _

1========

l-SE-TI-IN-G
ll--S-T.-AR-T--
I
~
SET RECORDING COND

I
MANU TRIG

I
LONG TIME HI
SPEED MANU
TRIG

__ 1__ J

"SETIING" "AUTOTRIG"
A malfunction canbe
displayed on"DATA
MONITOR" screen
automatically ifdetected.
EC-263 "MANU
TRIG"
A malfunction cannotbe
displayed on"DATA
MONITOR" screen
automatically evenif
detected.
SEF6740

TROUBLEDIAGNOSIS -General Description
Sensors

~ ECMActuators

~~.~ MEF036D
SEF234G Introduction

The engine hasanECM tocontrol majorsystems suchasfuel
control, ignitioncontrol, idleaircontrol system, etc.The ECM
accepts inputsignals fromsensors andinstantly drivesactua-
tors. Itis essential thatboth input andoutput signals areproper
and stable. Atthe same time,itis important thatthere areno
problems suchasvacuum leaks,fouled sparkplugs, orother
problems withtheengine.
It is much moredifficult todiagnose aproblem thatoccurs
intermittently ratherthancontinuously. Mostintermittent prob-
lems arecaused bypoor electric connections orimproper wir-
ing. Inthis case, careful checking ofsuspected circuitsmay
help prevent thereplacement ofgood parts.
A visual checkonlymaynotfind thecause ofthe problems. A
road testwith CONSULT oracircuit testerconnected shouldbe
performed. Followthe"Work Flow"onthe next page.
Before undertaking actualchecks, takejustafew minutes to
talk with acustomer whoapproaches withadriveability com-
plaint. Thecustomer cansupply goodinformation aboutsuch
problems, especially intermittent ones.Findoutwhat symptoms
are present andunder whatconditions theyoccur. A"Diagnos-
tic Worksheet" liketheexample onEC-267 shouldbeused.
Start yourdiagnosis bylooking for"conventional" problems
first. Thiswillhelp troubleshoot driveabilityproblemsonan
electronically controlledenginevehicle.

EC-264

TROUBLEDIAGNOSIS -General Description
Work Flow
CHECK IN
Listen tocustomer complaints. (Getsymptoms.)
...............................................STEPI
Check, printoutorwrite down, anderase Diagnostic TroubleCode(DTC).
Symptoms
collected. No
symptoms but
Malfunction Code
exists atSTEP II. ..
STEPII

•

Verify
thesymptom bydriving inthe condition the
customer described.
'1

..................................... STEPIII
Normal Code
(at STEP II) Malfunction
Code
(at STEP II)
Verify theDTC byperforming the"DTC CONFIRMATION PROCEDURE"
'1

...... STEP IV
Choose theappropriate action.
Malfunction Code
(at STEP IIor IV) Normal
Code(atboth STEP IIand IV)
BASIC INSPECTION
SYMPTOM BASIS(atSTEP Ior III) .
STEPV

'2

Perform inspections
according toSymptom
Matrix Chart.
TROUBLE DIAGNOSIS FORDTC XXX.
REPAIR/REPLACE
NG FINAL CHECK
Confirm thattheincident iscompletely fixedbyperforming BASICINSPECTION
and DTC CONFIRMATION PROCEDURE(orOVERALL FUNCTION CHECK).
OK
CHECK OUT STEP
VI
...................................... STEPVII
*1:
If
the incident cannotbeduplicated, refer10GI section ("Incident Simulation Tesls","HOWTOPERFORM EFFICIENT DIAG-
NOSIS FORANELECTRICAL INCIDENT").

*2: If
the on-board diagnostic systemcannotbeperformed, checkmainpower supply andground circuit.Refer10"TROUBLE
DIAGNOSIS FORPOWER SUPPLY", EC-286.

EC-265