check engine NISSAN ALMERA N15 1995 Service Manual

ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
[]K]

Malfunction Indicatorlamp(Mil)(Cont'd)

DIAGNOSTIC TESTMODE II-HEATED OXYGENSENSORMONITOR

In this mode, theMALFUNCTION INDICATORLAMPdisplays thecondition ofthe fuel mixture (leanor
rich) which ismonitored bythe heated oxygen sensor.
MALFUNCTION INDICATORLAMPFuelmixture condition inthe exhaust gasAirfuel ratio feedback controlcondition
ON Lean
Closedloopsystem
OFF Rich
Remains ONorOFF Anycondition
Openloopsystem
To check theheated oxygen sensorfunction, startengine inDiagnostic TestMode II.Then warm itup
until engine coolant temperature indicatorpointstomiddle ofgauge.
Next runengine atabout 2,000rpmforabout 2minutes underno-load conditions. Makesurethatthe•
MALFUNCTION INDICATORLAMPcomes ONmore than5times within 10seconds withengine running
at 2,000 rpmunder no-load.

EC-253

ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Cont'd)
FUNCTION
Diagnostictestmode Function
A technician canadjust somedevices
Work support
fasterandmore accurately byfollowing
indications onCONSULT.
Self-diagnostic results Self-diagnostic
resultscanberead and
erased quickly.
Data monitor
Input/Outputdatainthe ECM canberead.
CONSULT drivessomeactuators apart
Active test fromtheECM's andalso shifts some
parameters inaspecified range.
ECM partnumbers
ECMpartnumbers canberead.
Conducted byCONSULT insteadofatech-
Function test
niciantodetermine whethereachsystem
is "OK" or"NG".
WORK SUPPORT MODE
WORK ITEM
CONDITION USAGE
THRTL POSSENADJ
CHECKTHETHROTTLE POSITIONSENSORSIGNAL. Whenadjusting throttleposition
ADJUST ITTO THE SPECIFIED VALUEBYROTATING
sensorinitialposition
THE SENSOR BODYUNDER THEFOLLOWING CONDI-
TIONS .
• IGN SW"ON"
• ENG NOTRUNNING
• ACC PEDAL NOTPRESSED
IGNITION TIMINGADJ
•IGNITION TIMINGFEEDBACK CONTROLWILLBE
Whenadjusting initialignition
HELD BYTOUCHING "START".AFTERDOINGSO, timing
ADJUST IGNITION TIMINGWITHATIMING LIGHTBY
TURNING THECAMSHAFT POSITIONSENSOR.
IACV-AAC VALVEADJ
SETENGINE SPEEDATTHE SPECIFIED VALUEUNDER
Whenadjusting idlespeed
THE FOLLOWING CONDITIONS.
• ENGINE WARMED UP
• NO-LOAD
FUEL PRESSURE RELEASE •FUEL PUMP WILLSTOP BYTOUCHING "START"
Whenreleasing fuelpressure
DURING IDLING.
fromfuelline
CRANK AFEW TIMES AFTER ENGINE STALLS
EC-256

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

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

STEP
STEP I
STEP II
STEP III
STEP IV
STEP V
STEP VI
STEP VII
TROUBLE
DIAGNOSIS -General Description
Description forWork Flow

DESCRIPTION
Get detailed information abouttheconditions andtheenvironment whentheincident/symptom occurred
using the"DIAGNOSTIC WORKSHEET" asshown onthe next page.
Before confirming theconcern, checkandwrite down (printoutusing CONSULT) theDiagnostic Trouble
Code (DTC), thenerase thecode. TheDTC canbeused when duplicating theincident atSTEP
1/1
&
IV.
Study therelationship betweenthecause, specified byDTC, andthesymptom described bythe customer.
(The "Symptom MatrixChart" willbeuseful. RefertoEC-274.)
Try toconfirm thesymptom andunder whatconditions theincident occurs.
The "DIAGNOSTIC WORKSHEET" isuseful toverify theincident. ConnectCONSULT tothe vehicle inDATA
MONITOR (AUTOTRIG)modeandcheck realtime diagnosis results.
If the incident cannotbeverified, performINCIDENT SIMULATION TESTS.RefertoGI section.
If the malfunction codeisdetected, skipSTEP IVand perform STEPV.
Try todetect theDiagnostic TroubleCode(DTC) bydriving in(or performing) the"DTC CONFIRMATION
PROCEDURE". Checkandread theDTC byusing CONSULT.
During theDTC verification, besure toconnect CONSULT tothe vehicle inDATA MONITOR (AUTOTRIG)
mode andcheck realtime diagnosis results.
If the incident cannotbeverified, performINCIDENT SIMULATION TESTS.RefertoGI section.
In case the"DTC CONFIRMATION PROCEDURE"isnot available, performthe"OVERALL FUNCTION
CHECK" instead.TheDTC cannot bedisplayed bythis check, however, thissimplified "check"isan effec-
tive alternative.
The "NG" result ofthe "OVERALL FUNCTIONCHECK"isthe same asthe DTC detection.
Take theappropriate actionbasedonthe results ofSTEP Ithrough IV.
If the malfunction codeisindicated, proceedtoTROUBLE DIAGNOSIS FORDTCXX.
If the normal codeisindicated, proceedtothe BASIC INSPECTION. RefertoEC-271. Thenperform inspec-
tions according tothe Symptom MatrixChart.RefertoEC-274.
Identify wheretobegin diagnosis basedonthe relationship studybetween symptom andpossible causes.
Inspect thesystem formechanical binding,looseconnectors orwiring damage using(tracing) "Harness
Layouts".
Gently shaketherelated connectors, components orwiring harness withCONSULT setin"DATA MONITOR
(AUTO TRIG)" mode.
Check thevoltage ofthe related ECMterminals ormonitor theoutput datafrom therelated sensors with
CONSULT. RefertoEC-277.
The "DIAGNOSTIC PROCEDURE" inEC section contains adescription basedonopen circuit inspection. A
short circuit inspection isalso required forthe circuit checkinthe DIAGNOSTIC PROCEDURE. Fordetails,
refer toGI section ("HOWTOPERFORM EFFICIENT DIAGNOSIS FORANELECTRICAL INCIDENT","Circuit
Inspection").
Repair orreplace themalfunction parts.

.

Once youhave repaired thecircuit orreplaced acomponent, youneed torun theengine inthe same condi-
tions andcircumstances whichresulted inthe customer's initialcomplaint.
Perform the"DTC CONFIRMATION PROCEDURE"andconfirm thenormal code(Diagnostic troublecodeNo.
55) isdetected. Ifthe incident isstill detected inthe final check, perform STEPVIby using adifferent
method fromtheprevious one.
Before returning thevehicle tothe customer, besure toerase theunnecessary (alreadyfixed)DTCinECM.
(Refer toEC-252.)

EC-266

TROUBLEDIAGNOSIS -General Description
ill]

Diagnostic TroubleCode(DTC) Chart(Cont'd)

x:
Applicable
-: Not applicable
"DTC *1
*2
Check Items CONFIRMATION
"OVERALLFUNC-
Fail ReferencePage
(Possible Cause) PROCEDURE"
TIONCHECK"
Safe
Quick Ref. QuickRef. System
• Harness orconnectors
(The sensor circuitisopen orshorted.)
• Camshaft positionsensor
RUNNING
--

EC-289
• Starter motor
• Starting systemcircuit(ELsection)
• Dead (Weak) battery
• Harness orconnectors

-

(The sensor circuitisopen orshorted.) RUNNING
RUNNING
X

EC-293
• Mass airflow sensor
• Harness orconnectors
(The sensor circuitisopen orshorted.) IGN:
ON
-

X
EC-297
• Engine coolant temperature sensor
• Harness orconnectors
(The ignition primary circuitisopen orshorted.)
• Power transistor unit RUNNING

--

EC-301
• Camshaft positionsensor
• Camshaft positionsensorcircuit
• Harness orconnectors
(The sensor circuitisopen orshorted.) RUNNING

--

EC-306
• Knock sensor
• Harness orconnectors
(The sensor circuitisopen orshorted.)

-
IGN:
ON
X
EC-309
• Throttle position sensor
• No failure

--
-
-

*2: •The "OVERALL FUNCTIONCHECK"isasimplified andeffective waytoinspect acomponent orcircuit.
In some cases, the"OVERALL FUNCTIONCHECK"isused rather thana"DIAGNOSTIC TROUBLECODECONFIRMA-
TION PROCEDURE".
When noDTC CONFIRMATION PROCEDUREisavailable, the"NG" result ofthe OVERALL FUNCTION CHECKcanbe
considered tomean thesame asaDTC detection .
• During an"NG" OVERALL FUNCTION CHECK,theDTC might notbeconfirmed.

EC-269
•

TROUBLEDIAGNOSIS -General Descrip_ti_on
1S_R_'

Basic Inspection
Precaution:
Perform BasicInspection withoutelectrical ormechanical loads
applied;
• Headlamp switchisOFF,
• Air conditioner switchisOFF,
• Rear defogger switchisOFF,
• Steering wheelisinthe straight-ahead position,etc.

m

BEFORE STARTING

1. Check service records forany recent •
repairs thatmay indicate arelated
problem, orthe current needfor
scheduled maintenance.
2. Open engine hoodandcheck thefol-
lowing:
• Harness connectors forimproper con-
nections
• Vacuum hosesforsplits, kinks,or
improper connections
• Wiring forimproper connections,
pinches, orcuts
Goto
(I.

No

CONNECT
CONSULTTOTHE VEHICLE.

Connect "CONSULT" tothe data link
connector forCONSULT andselect
"ENGINE" fromthemenu. Referto

EC-254.
DOES ENGINE START?

\\

~
~ SEF1421

START

•
IGN TIMING ADJ.
0

IGNITION TIMINGFEEDBACK
CONTROL WILLBEHELD BY
TOUCHING START
AFTER DOING SO,ADJUST
IGNITION TIMINGWITHA
TIMING LIGHTBYTURNING
THE CAMSHAFT POSITION
SENSOR.

SEF555N
Yes

CHECK IGNITION TIMING.

(ij\
1.Warm upengine sufficiently.
~ 2.Select "IGNTIMING ADJ"in
"WORK SUPPORT" mode.
3. Touch "START".
4. Check ignition timingatidle
using timing light.

Ignition timing:
15°::f:2° BTDC

~ 1Warm upengine sufficiently.

~ 2:
Stop engine anddisconnect
throttle position sensorhar-
ness connector.
3. Start engine.
4. Check ignition timingatidle
using timing light.

Ignition timing:
15°::f:2° BTDC
OK

(Go to
@
onnext page.) Adjust
ignition timingby
turning distributor.

EC-271