NISSAN ALMERA N15 1995 Service Manual

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

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
KEY POINTS

WHAT .....
Vehicle &engine model

WHEN
Date,Frequencies
WHERE Roadconditions
HOW Operatingconditions,
Weather conditions,
Symptoms
SEF907L
WORKSHEET SAMPLE Diagnostic
Worksheet

There aremany operating conditions thatlead tothe malfunc-
tion ofengine components. Agood grasp ofsuch conditions can
make troubleshooting fasterandmore accurate.

In
general, eachcustomer feelsdifferently aboutaproblem. It
is important tofully understand thesymptoms orconditions for
a customer complaint.
Utilize adiagnostic worksheet liketheone shown belowin
order toorganize allthe information fortroubleshooting.

•

Customer name
MR/MS Model

&
Year VIN
Engine
#
Trans. Mileage
Incident Date Manuf.Date InService Date

o
Impossible tostart
o
No combustion

o
Partial combustion

o
Startability
o

Partial combustion affectedbythrottle position

o
Partial combustion NOTaffected bythrottle position

o
Possible buthard tostart
o
Others [
]

o
No fast idle
o
Unstable
o
High idle

o
Low idle

[J
Idling

o
Others [
]

Symptoms
[J
Stumble
o
Surge
o
Knock

o
Lack ofpower

o
Driveability
o

Intake backfire

o
Exhaust backfire

o
Others [
]

o
At the time ofstart
o
While idling

o
Engine stall
o

While accelerating
o
While decelerating

o
Just after stopping
o
While loading
Incident occurrence
o

Just after delivery
o
Recently

o
Inthe morning
o
At night
o
Inthe daytime
Frequency
o

All the time

o
Under certain conditions
o
Sometimes
Weather conditions
o
Not affected
Weather
o
Fine DRaining
o
Snowing
o
Others [
]

Temperature
o
Hot
o
Warm
o
Cool
o
Cold
o
Humid
of

o
Cold
o

During warm-up

o
After warm-up
Engine conditions
Enginespeed

I
I
I

I
I
I
I

I
I

0 2,000 4,000
6,000 8,000rpm

Road conditions
o

Intown
o
Insuburbs
o
Highway
o
Off road (up/down)

o
Not affected

o
At starting
o
While idling
o
At racing

o
While accelerating
o
While cruising
Driving conditions
o

While decelerating
o
While turning (RH/LH)
Vehicle speed
I
I
I
I

I
I
II

I
I
I
II

0 10 20 3040
5060
MPH

Malfunction indicatorlamp
o
Turned on
o
Not turned on

EC-267

TROUBLEDIAGNOSIS -General Description
Diagnostic TroubleCode(DTC) Chart
ENGINE RELATED ITEMS

Diagnostic Detecteditems
trouble code
No. (ScreentermsforCONSULT, Malfunction
isdetected when...
MIL "SELF-DIAG
RESULTS"mode)

11
Camshaftpositionsensorcircuit •Either
1
0
or
180
0
signal isnot detected bythe ECM forthe first few
(CAMSHAFT POSISEN) secondsduringengine cranking .
• Either
1
0
or
180
0
signal isnot detected bythe ECM often enough
while theengine speedishigher thanthespecified rpm.
• The relation between
1"
and
180"
signals isnot inthe normal range
during thespecified rpm.

12
Massairflow sensor circuit
•An excessively highorlow voltage isentered toECM.
(MASS AIRFLOW SEN) •Voltage senttoECM isnot practical whencompared withthecam-
shaft position sensorsignalandthrottle position sensorsignal.

13
Enginecoolant temperature sen-•An excessively highorlow voltage fromthesensor isdetected by
sor circuit theECM.
(COOLANT TEMPSEN)

21
Ignitionsignalcircuit
•The ignition signalinthe primary circuitisnot detected bythe ECM
(IGN SIGNAL-PRIMARY)
duringengine cranking orrunning.

34
Knocksensor circuit •An excessively loworhigh voltage fromthesensor isdetected by
(KNOCK SENSOR) theECM .

43
Throttlepositionsensorcircuit •
An excessively loworhigh voltage fromthesensor isdetected by
(THROTTLE POSISEN)
theECM.
• Voltage senttoECM isnot practical whencompared withthemass
air flow sensor andcamshaft positionsensorsignals.

55
Nofailure •No malfunction relatedtoOBD system isdetected byeither ECMor
(NO SELF DIAGNOSTIC FAILURE
AIT
control unit.
INDICATED ...)
*1: This isQuick Reference of"DTC CONFIRMATION PROCEDURE".
Details aredescribed ineach TROUBLE DIAGNOSIS FORDTC
XX.

Abbreviations areasfollows:
IGN: ON :Turning theignition switchONisrequired forthe ECM todetect amalfunction (ifone exists).
RUNNING: Runningengineisrequired forthe ECM todetect amalfunctiQn (ifone eXists).

EC-268

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 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 -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