engine NISSAN ALMERA N15 1995 Service Manual

TROUBLEDIAGNOSIS FORDTC21
Ignition Signal
COMPONENT DESCRIPTION
Ignition coil
&
power transistor (Builtintodistributor)

The ignition coilisasmall molded type.Theignition signalfrom
the ECM issent tothe power transistor. Thepower transistor
switches onand offthe ignition coilprimary circuit.Asthe pri-
mary circuit isturned onand off,the proper highvoltage is
induced inthe coil secondary circuit.

Diagnostic Trouble
Code No.

21
Malfunction
isdetected when...
• The ignition signalinthe primary circuitisnot sent
to ECM during engine cranking orrunning. Check
Items
(Possible Cause)
• Harness orconnectors
(The ignition primary circuitisopen orshorted.)
• Power transistor unit.
• Resistor
• Camshaft positionsensor
• Camshaft positionsensorcircuit
•

DIAGNOSTIC TROUBLECODECONFIRMATION
PROCEDURE
Note: Ifboth DTC11and 21are displayed, performTROUBLE
DIAGNOSIS FORDTC11first. Refer toEC-289.

(F.I\ 1)Turn ignition switch"ON".
~ 2)Select "DATA MONITOR" modewithCONSULT.
3) Start engine. (Ifengine doesnotrun, turn ignition
switch to"START" foratleast 5seconds.)

---------- OR----------

~ 1)Turn ignition switch"ON".
~ 2)Start engine. (Ifengine doesnotrun, turn ignition
switch to"START" foratleast 5seconds.)
3) Turn ignition switch"OFF", waitatleast 7seconds
and then turn"ON".
4) Perform "Diagnostic TestMode II"(Self-diagnostic
results) withECM.

EC-301

•

Check
thefollowing.
• Harness connectors

QD,@

• Harness connectors

@,@D

• Harness foropen or
short between ignition
coil and ignition switch
If NG, repair harness or
connectors.

Yes

NG

INSPECTION
START

OK

Turn
ignition switch"OFF". andrestart
engine.

Is engine running?
CHECK POWER SUPPLY.

1. Turn ignition switch"OFF".
2. Disconnect ignitioncoilharness con-
nector.
3. Turn ignition switch"ON".
4. Check voltage between terminal

(J)
and ground withCONSULT or
tester.

Voltage: Batteryvoltage
SEF010P
TROUBLE
DIAGNOSIS FORDTe21
Ignition Signal(Cont'd)
DIAGNOSTIC PROCEDURE
CHECK GROUND CIRCUIT.
AEC69a
1.Turn ignition switch"OFF".
2. Disconnect powertransistor harness
connector.
3. Check harness continuity between
terminal
@
and engine ground.

Continuity shouldexist.
If
OK. check harness forshort.

~i5

@a

~ SEF4690

~iv
~i5

II
ECM
'gCONNECTORII
(1!2IffllsI6) CHECK
INPUTSIGNAL CIRCUIT.

1. Disconnect ECMharness connector.
2. Check harness continuity between
ECM terminal
G)
and power transis-
tor terminal
G).
Continuity shouldexist.

If OK. check harness forshort.

OK

CHECK COMPONENTS
(Ignition coil,power transistor).
Refer to"COMPONENT INSPECTION".

EC-305. NG
NG
NG
Repair
harness orcon-
nectors.
Repair harness orcon-
nectors.
Replace malfunctioning
component(s).

OK
SEF4700
Disconnect andreconnect harnesscon-
nectors inthe circuit. Thenretest.
Trouble isnot fixed.
Check ECMpinterminals fordamage
and check theconnection ofECM har-
ness connector. ReconnectECMhar-
ness connector andretest.
INSPECTION END

EC-303

Repairharness orcon-
nectors.
Replace resistor.

NG
NG

CHECK COMPONENT
(Resistor).
Refer to"COMPONENT INSPECTION"
on next page.

CHECK
INPUTSIGNAL CIRCUIT.

1. Stop engine.
2. Disconnect ignitioncoilharness con-
nector.
3. Strip tapecovering resistor.
4. Disconnect ECMharness connector.
5. Check harness continuity between
ignition coilterminal
CID
and resistor
terminal
(!).
resistor terminal
@

and ECM terminal
@.

Continuity shouldexist.

If OK, check harness forshort.

OK
TROUBLE
DIAGNOSIS FORDTC21
Ignition Signal(Cont'd)

@

SEF471Q
(;J~i5
~i5

1
~~Q~
'Cf~OONNlliOR~

LllJ
~i5

cffu

[ill

Disconnectandreconnect harnesscon-
nectors inthe circuit. Thenretest.
Trouble isnot fixed.
Check ECMpinterminals fordamage
and check theconnection ofECM har-
ness connector. Reconnect ECMhar-
ness connector andretest.
INSPECTION END

EC-304

TROUBLEDIAGNOSIS FORDTC34
Knock Sensor (KS)

The knock sensor isattached tothe cylinder block.Itsenses
engine knocking usingapiezoelectric element.Aknocking

vibr
ion
fromthecylinder blockissensed asvibrational pres-
sure. Thispressure is
converted
intoa
voltage
signalandsent
to the ECM.

PIEZO-ELEMENT SEF598K

Diagnostic
Trouble Code Malfunctionisdetected when....
No.
34 •An excessively loworhigh voltage fromtheknock
sensor issent toECM. Check
Items
(Possible Cause)
• Harness orconnectors
(The knock sensor circuitisopen orshorted.)
• Knock sensor

DIAGNOSTIC TROUBLECODECONFIRMATION
PROCEDURE

fiii\
1)Turn ignition switch"ON"andselect "DATA

\J!}
MONITOR" modewithCONSULT.
2) Start engine andrunitfor atleast 5seconds atidle
speed.

----------OR -----------

1) Start engine andrunitfor atleast 5seconds atidle
speed.
2) Turn ignition switch"OFF", waitatleast 7seconds
and then turn"ON".
3) Perform "Diagnostic TestMode II"(Self-diagnostic
results) withECM.

EC-306

Repairharness orcon-
nectors.
Repair harness orcon-
nectors.
Replace knocksensor.

NG

~

INSPECTION
START
Loosen andretighten engineground
screws.

OK

Disconnect andreconnect harnesscon-
nectors inthe circuit. Thenretest.

OK

CHECK COMPONENT
(Knock sensor).
Refer to"COMPONENT INSPECTION"
below.
Troubleisnot fixed.
Check ECMpinterminals fordamage
and check theconnection ofECM har-
ness connector. ReconnectECMhar-
ness connector andretest,
OK

m
CHECK SUB.HARNESS CIRCUIT.

1. Disconnect knocksensor harness
connector.
2. Check harness continuity between
knock sensor harness connector ter-
minal
@
and knock sensor sub-har-
ness connector terminal
CD.

Continuity shouldexist.

If
OK, check harness forshorl.

fa
CHECK INPUTSIGNAL CIRCUIT.

1. Turn ignition switch"OFF".
2. Disconnect ECMharness connector
and knock sensor harness connector.
3. Disconnect sub-harness connectors

@,@D.

4. Check harness continuity between
terminal
CD
and ECM terminal
@.

Continuity shouldexist.
If OK, check harness forshorl.

MEC757B
MEC7568
TROUBLE
DIAGNOSIS FORDTC34

Knock Sensor (KS)(Cont'd)

DIAGNOSTIC PROCEDURE
~15
..
~
\ili:tV
~~

\tiiliJ

~15

ECM
BCONNECTORII

27
,,~n~(

r\r~\//\ \
AY

..("'~Inlake manifold

~

\
fa

II

INSPECTIONEND

COMPONENT INSPECTION

Knock sensor
• Use anohmmeter whichcanmeasure morethan10MO.
1. Disconnect knocksensor harness connector.
2. Check resistance betweenterminal
@
and ground.
Resistance: 500-620 kO[at25°C (77°F))

CAUTION:
Do not use any knock sensors thathave been dropped orphys-
ically damaged. Useonly newones.

AEC719
EC-308

TROUBLEDIAGNOSIS FORDTC43
SEF089K Throttle
Position Sensor

The throttle position sensorresponds tothe accelerator pedal
movement. Thissensor isakind ofpotentiometer whichtrans-
forms thethrottle position intooutput voltage, andemits the
voltage signaltothe ECM. Inaddition, thesensor detects the
opening andclosing speedofthe throttle valveandfeeds the
voltage signaltothe ECM.
Idle position ofthe throttle valveisdetermined
by
the ECM
receiving thesignal fromthethrottle position sensor.Thisone
controls engineoperation suchasfuel cut.

•

SEF520Q

VI

Supplyvoltage:
~ 4.55V (Applied be~VoIee~_terminals NO.1and3)
.~

2

[f~.. ~
L

L
1
&c
~ ~M

Throttle position sensor g
-g

:; ~ 0.5

0.

8 ~
00 -~---_. 90
Throttle valveopening angle(deg.)

Diagnostic Trouble
Code No. Malfunction
isdetected when... Check
Items
(Possible Cause)

43
•
An excessively loworhigh voltage fromthesensor •Harness orconnectors
is sent toECM. (Thesensor circuitisopen orshorted.)
• Throttle position sensor

EC-309

Repairharness orcon-
nectors.

NG
CHECK POWER SUPPLY.

1. Turn ignition switch"OFF".
2. Disconnect throttleposition sensor
harness connector.
3. Turn ignition switch"ON".
4. Check voltage between terminal
(1)

and ground withCONSULT ortester.

Voltage: Approximately 5V

INSPECTION
START

TROUBLE
DIAGNOSIS FORDTC43
Throttle Position Sensor(Cont'd)
DIAGNOSTIC PROCEDURE
MEC723B

,,~n~7
r~r~\
n\ \
!Y

-z~lntake manifold

[L~
SEF480QOK
CHECK GROUND CIRCUIT.

1. Turn ignition switch"OFF".
2. Loosen andretighten engineground
screw.
3. Check harness continuity between
terminal
@
and engine ground.

Continuity shouldexist.
If
OK, check harness forshort.

OK
CHECK INPUTSIGNAL CIRCUIT.

1. Disconnect ECMharness connector.
2. Check harness continuity between
ECM terminal
@)
and terminal
@.

Continuity shouldexist.

If OK, check harness forshort.

OK

ADJUST THROTTLE POSITIONSEN-

SOR.

Perform "BasicInspection", EC-271.

OK NG

NG
Check
thefollowing.
• Harness foropen or
short between ECM
and throttle position
sensor

If
NG, repair harness or
connectors.
Repair harness orcon-
nectors

~io
~ SEF481Q
CHECK
COMPONENT
(Throttle positionsensor).
Refer to"COMPONENT INSPECTION"
on next page.

OK•

Disconnect andreconnect harnesscon-
nectors inthe circuit. Thenretest.
Trouble isnot fixed.
NG

Replace throttleposition
sensor. Toadjust it,per-
form "Basic Inspection",
EC-271.

~io ~i5

II
ECM
~CONNECTORII
o::fl\])

20
Check
ECMpinterminals fordamage
and check theconnection ofECM har-
ness connector. Reconnect ECMhar-
ness connector andretest.
INSPECTION END

SEF482Q EC-312

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
Start Signal (Cont'd)
DIAGNOSTIC PROCEDURE
• START SIGNAL CKT•

INSPECTIONSTART

fa CHECK OVERALL FUNCTION.

(ij\
1,Turn ignition switch"ON",
~ 2,Perform "STARTSIGNALCKT"
in "FUNCTION TEST"mode
with CONSULT,

OR

rif\
1,Turn ignition switch"ON",
~ 2,Check "START SIGNAL" in
"DATA MONITOR" modewith
CONSULT,

1
CLOSE THROTILE, SHIFT
TO POR NRANGE
2 TOUCH STARTAND
START ENGINE
IMMEDIATELY

NEXT
II
START

fa
-(:(MONITOR -(:(NO FAIL

0

START SIGNAL OFF
CLSDTH/PSW ON
AfRCONDSIG OFF
PIN POSI SW ON
SEF191L

IGN"ON"

IGN "START"
OFF
ON OK

INSPECTION END

___ RE_C_O_R_D __
I

SEF111P

Checkthefollowing,
• Harness connectors

@,@

• 7,5A fuse
• Harness foropen or
short between ECMand
ignition switch
If NG, repair harness or
connectors,

NG
CHECK INPUTSIGNAL CIRCUIT.

1, Turn ignition switch"OFF",
2, Disconnect ECMharness connector
and ignition switchharness connec-
tor,
3, Check harness continuity between
ECM terminal
@
and terminal
@,

Continuity shouldexist.

If OK, check harness forshort

OK

OR

1, Turn ignition switchto
"START",
2 Check voltage between ECM
terminal
@
and ground,

Voltage: Ignition switch"START"
Battery voltage
Exceplabove
Approximately OV
MEC725B

~15
~

t:1tlliJ

~i3

ECM
E[CONNECTORII

34
~

II

ECM ~CONNECTORI
34

Disconnectandreconnect-harness con-
nectors inthe circuit Thenretest
Trouble isnot fixed,

MEC760B
Check
ECMpinterminals fordamage
and check theconnection ofECM har-
ness connector, ReconnectECMhar-
ness connector andretest
INSPECTION END

EC-318

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
Exhaust GasRecirculation (EGR)Valveand
EVAP Canister PurgeControl
SYSTEM DESCRIPTION

I
Camshaft positionsensor
I

Engine speed
EGRvalve

I
Mass
airflow sensor
I

Amount ofintake air ECM

&
EVAP
(ECCS canister

I
~Engine
coolanttemperature control
purgecon-
Engine coolant temperature sensor
module)trolsole-

I
noid
valve
Ignition switch
I

Start signal

I

This system cutsandcontrols vacuumappliedto
EGR valve andEVAP canister tosuit engine oper-
ating conditions. Thiscut-and-control operation
is accomplished throughtheECM andtheEGR
valve
&
EVAP canister purgecontrol solenoid
valve. WhentheECM detects anyofthe following
conditions, currentflowsthrough thesolenoid
valve. Thiscauses theport vacuum tobe dis-
charged intotheatmosphere. TheEGR valve and
EVAP canister remainclosed.
•

•

•
•
•

•
Low
engine coolant temperature
Engine starting
High-speed engineoperation
Engine idling
Excessively highengine coolant temperature
Mass airflow sensor malfunction
•

Exhaust pressure COMPONENT
DESCRIPTION
EGR valve

The EGR valve controls theamount ofexhaust gasrouted tothe
intake manifold. Vacuumisapplied tothe EGR valve in
response tothrottle valveopening. Thevacuum controls the
movement ofataper valve connected tothe vacuum diaphragm
in the EGR valve.

SEF783K EGRC-BPT valve

The EGRC-BPT valvemonitors exhaustpressure toactivate the
diaphragm, controllingthrottlebodyvacuum appliedtothe EGR
valve. Inother words, recirculated exhaustgasiscontrolled in
response topositioning ofthe EGR valve ortoengine operation.

SEF529K
~ Vacuumsignal
SEF240PE EGR
valve
&
EVAP canister purgecontrol solenoid valve

The EGR valve
&
EVAP canister purgecontrol solenoid valve
responds tosignals fromtheECM. When theECM sends anON
(ground) signal,thecoil inthe solenoid valveisenergized. A
plunger willthen move tocut the vacuum signal(fromthethrot-
tle body tothe EGR valve andEVAP canister purgevalve).
When theECM sends anOFF signal, thevacuum signalpasses
through thesolenoid valve.Thesignal thenreaches theEGR
valve andEVAP canister.

EC-319

•

INSPECTION
START

m
CHECK OVERALL FUNCTION.
~INSPECTION
END
1. Start engine andwarm itup suffi-
ciently.
2. Perform diagnostic testmode II(Self-
diagnostic results).
Make surethatDiagnostic trouble
code No.12isnot displayed.
3. Keep
engine speedatabout 2,000
rpm. Make surethatEGR valve
spring moves upand down when
engine israced toabout 4,000rpm.
(Use yourfinger.)
NG

m
CHECK VACUUM SOURCETOEGR OK
CHECK COMPONENTS

----..

VALVE. (EGR
valve andEGRC-
1. Disconnect vacuumhosetoEGR BPT
valve).
valve. Refer
to"COMPONENT
2. Disconnect
vacuumhosetoEVAP INSPECTION",
EC-323
canister.
3. Check vacuum existence underthe NG
following conditions.
Engine speedis4,000 rpm:
Vacuum shouldnotexist.
Replacemalfunctioning
Engine speedis2,000 rpm:
component(s).
Vacuum shouldexist.
NG

[!J
(!]

CHECK CONTROL FUNCTION. OK
CHECK VACUUM HOSE.

-----.-

Check voltage between ECMterminal Check
vacuum hosefor

@
andground underthefollowing clogging,
cracksor
conditions. improper
connection.
Engine speedis4,000 rpm
0.6 -O.BV
Engine speedis2,000 rpm
Battery voltage
~NG

+
-
MEF637B
MEF955D
TROUBLE
DIAGNOSIS FORNON-DETECTABLE ITEMS
[1[J

Exhaust GasRecirculation (EGR)Valveand
EVAP Canister PurgeControl (Cont'd)
DIAGNOSTIC PROCEDURE

~)5
~~II
EGRC-BPT valve
~~uu~ hose
connected toEGR valve~

(
~
'

MEC761B
Clogging

[!J

r----, ~
CONNECT

II
ECM ~CONNECTORIIl.imJ
£)

105

::::.S.-

~P"P"
'00","'00

MEF521E
EC-321