1995 NISSAN ALMERA N15 Service Manual

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

I!]
CHECK IDLEADJ. SCREW INITIALSET
NG
Adjust engine speedby

---..

RPM.
turningidleadjusting

00
1.
Select "IGNTIMING ADJ"in screw.
"WORK SUPPORT" mode.
2. When touching "START",
does engine speedfallto
750:!: 50rpm
(AfT
in
"N"
posi-
tion)?
OR

00
Does
engine runat750:!: 50rpm

(AfT
In
"N"
position)?
OK
Reconnect throttleposition sensorhar-
ness connector.

Ii
CHECK THROTTLE POSITIONSENSOR
NG
Adjust outputvoltage to

IDLE POSITION.
---..

0.50Vbyrotating throttle

00
1.
Perform ''THRTLPOSSEN
positionsensorbody.
ADJ" in"WORK SUPPORT"

1

mode.
2. Check thatoutput voltage of

RESETIDLEPOSITION

throttle position sensoris

MEMORY.

approx. 0.35to0.65V (Throttle
1.Warm upengine suffi-
valve fullycloses.) and"CLSD ciently.
2. Turn ignition switch
THLIPOSI" stays"ON".
"OFF"andwait at
OR least5seconds.

00
Measure
outputvoltage ofthrot- 3.
Disconnect throttle
position sensorhar-
tie position sensorusing
nessconnector.
voltmeter, andcheck thatitis

4.
Start engine andwait
approx. 0.35toO.65V. (Throttle at
least 5seconds in
"N" position.
valve fullyclosed.)
5.Reconnect throttle
OK • position
sensorhar-
ness connector while
running engine.
~
1

,

THRTL
POSSEN O,52V

SEF165P

•••
ADJMONITOR •••

TROUBLE
DIAGNOSIS -General Description
Basic Inspection (Cont'd)

@

========
MONITOR
========

CMPS.RPM (REF)Orpm
CLSDTHUP ON

Ii
•
THRTL POSSENADJ
.0

I!]

•IGN TIMING ADJ.

0

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

I
START

I

SEF546N

CID

(Go tonext page)

EC-272

TROUBLEDIAGNOSIS -General Description
Basic Inspection (Conl'd)
@
CHECK IDLESPEED

(ij\
Readtheengine idlespeed in
~ "DATA MONITOR" modewith
CONSULT.

MfT
=
800:1: 50
rpm

AfT
=
800:1: 50
rpm
(in
uN"
position)
OR
fiY\
Check idlespeed.

~ MfT
=
800:1:50
rpm

AfT =800:1: 50
rpm
(in
uN"
posillon)
OK

After thisinspection, unnecessary diag-
nostic trouble codeNo.might bedis-
played.
Erase thestored memory inECM.

OK

INSPECTION END

EC-273 NG

Adjust idlespeed. Refer
to
EC-243.

•