NISSAN ALMERA N15 1995 Service Manual

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
Idle AirControl Valve(IACV)-Air Regulator
SYSTEM DESCRIPTION
Camshaft positionsensor
Ignition switch Engine
speed
Start signal ECM
(ECCS
control
module) IACV-air
regulator

The IACV-air regulator iscontrolled bythe ECM
at the same timeasfuel pump ON-OFF control.
Condition
Ignition switchisturned to"ON"
Engine running andcranking
When engine isstopped
Except asshown above IACV-air
regulator
operation
Operates for5
seconds
Operates
OFF in1second
OFF

Bimetal

...

Air flow
SEF095K COMPONENT
DESCRIPTION

IACV-air regulator providesanair bypass whentheengine ;s
cold forafast idleduring warm-up.
A bimetal, heaterandrotary shutter arebuilt intotheIACV-air
regulator. Whenthebimetal temperature islow, theairbypass
port opens. Asthe engine startsandelectric currentflows
through aheater, thebimetal beginstoturn theshutter toclose
the bypass port.Theairpassage remainscloseduntilthe
engine stopsandthebimetal temperature drops.

EC-332

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS[]:[]
Idle AirControl Valve(IACV)-Air Regulator
(Cont'd)

EC-AIRREG-01

IN.61IN•6
1
B/L B/W

I I

B/L B/W

IT
I~IIFCEL
n

PUMP

U
RELAY

IbJdlIbiJlCBD
B/P B/Y
Refer
toEL-POWER.

•

<:E>:

AIT
models

:
MITmodels
... :Detectable line
for DTC
---: Non-detectable
line forDTC

t

14>
~

B/Y B/YB/Y

r=b@})
r-!-,
@
,..-!-,
@

I~ICHID
~(E203)~(E20t)

B/Y B/YB/Y

t_f

I

B/Y

rn
1
IACV-AIR
REGULATOR

Clli:4)

~ B

I

B

1$1
(E227)

(ffi)

B

In

B BB

fJ
1

mm

ECM
(ECCS
CONTROL
MODULE)

(ill

FUSE
BLOCK
(JIB)


15A

[ill

B
IP
tG"Ai'\\

d:::,~

IllJl
C£[)

B/P

I

B/P

~
FPR
IGNITION
SWITCH
ON orSTART

ACBD

T
L
~(E203)

rnrn:tzlID
GY
ffiill@W

~B .r.'T;:;,..

(Eli4)

LJ...1J£p
GY
Refer
tolast page
(Foldout page).

CHID
(EJon

,

~

~@

~GY

em
L

HEC013
EC-333

ReplaceIACV-air regula-
tor. Check
thefollowing.
• Harness connectors

Cill),
@ID

• Harness foropen or
short between IACV-air
regulator andbody
ground
If NG, repair harness or
connectors.

NG

I

INSPECTION
START

OK.

INSPECTION END

OK

CHECK
GROUND CIRCUIT.
1. Turn ignition switch"OFF".
2. Check harness continuity between
terminal
@
and body ground.
Continuity shouldexist.

If
OK, check harness forshort.
CHECK COMPONENT
(IACV-air regulator).
Refer to"COMPONENT INSPECTION"
below.

I

CHECK CONTROL FUNCTION. NG
Check fuelpump control
1. Turn ignition switch"ON".
~

circuit.
2. Pinch fuelfeed hose withfingers. (See
page EC-327.)
Fuel pressure pulsation shouldbefelt
on the fuel feed hose for5seconds
after ignition switchisturned "ON".

I;)
1
0K
CHECK POWER SUPPLY. NG
Check thefollowing.
1. Turn ignition switch"OFF".
~

•Harness connectors
2. Disconnect IACV-airregulator har-
@,@})

ness connector. •
Harness connectors
3. Turn ignition switch"ON".
@D,

(M/T
mod-
4. Check voltage between terminal
G)
els)
and ground. •Harness connectors
Battery voltage shouldexistfor5sec.
@,

@
(A/Tmodels)
onds afterignition switchisturned •
Harness foropen or
"ON". short
between IACV-air
OK regulator
andfuel pump
relay

If
NG, repair harness or
connectors.

MEC7368
TROUBLE
DIAGNOSIS FORNON-DETECTABLE ITEMS~
Idle AirControl Valve(IACV)-Air Regulator
(Cont'd)
DIAGNOSTIC PROCEDURE

~15
~
~
~15

~ ~
MEC7378COMPONENT INSPECTION
IACV-air regulator

Disconnect IACV-airregulator harnessconnector.
• Check IACV-air regulator resistance.
Resistance: Approximately
70•80n
[at25°C (77°F))
• Check IACV-air regulator forclogging.

EC-334

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
SYSTEM DESCRIPTION Idle
AirControl Valve(IACV) -Auxiliary Air
Control (AAC)Valve

Camshaft positionsensor Engine
speed

~

I

Amount ofintake air
Mass airflow sensor

I

Engine coolant temperature sensor Engine
coolant temperature
I
Ignition switch Start
signal

I

Throttle position sensor Throttle
"position

I
ECM
Inhibitor switch(A/Tmodels)/ Park/Neutral
position (ECCS
control
!
IACV-AAC valve
I

Neutral position switch(M/Tmodels)
module)
Air conditioner switch Air
conditioner operation
Power steering oilpressure switch Power
steering loadsignal

I
Battery Battery
voltage
Vehicle speedsensor Vehicle
speed
I

l
Cooling fan Cooling
fanoperation

I

This system automatically controlsengineidlespeed toaspecified level.Idlespeed iscontrolled
through fineadjustment ofthe amount ofair which bypasses thethrottle valveviaIACV-AAC valve.The
IACV-AAC valverepeats ON/OFF operation according tothe signal sentfrom theECM. Thecamshaft
position sensordetects theactual engine speedandsends asignal tothe ECM. TheECM thencontrols
the ON/OFF timeofthe IACV-AAC valvesothat engine speedcoincides withthetarget valuememo-
rized inECM. Thetarget engine speedisthe lowest speedatwhich theengine canoperate steadily.
The optimum valuestored inthe ECM isdetermined bytaking intoconsideration variousengine
conditions, suchasduring warmup,deceleration, andengine load(airconditioner, powersteering and
cooling fanoperation).

COMPONENTDESCRIPTION
IACV-AAC valve

The IACV-AAC valveismoved byON/OFF pulsesfromtheECM.
The longer theONpulse, thegreater theamount ofair that will
flow through thevalve. Themore airthat flows through the
valve, thehigher theidle speed.

Air SEF040E
EC-335
•

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS~
Idle AirControl Valve(IACV) -Auxiliary Air
Control (AAC)Valve(Cont'd)

EC-AAC/V-01

Refer toEL-POWER.
ECM (ECCS
CONTROL
MODULE)

C£I)

~ ~GY ~~

GIIDID
S
BR

I

$-~
BR BR

1r.fJ1
@)
1$1
rn>
(E203) (E201)

BR SR

*_1
I

BR

~I
IACV-AAC

VALVE

(E213)

~ SB

I

SB

14J1
(E227)

(F12)

SB
I

SB
~
ISC

~ (E213)
~@

@
SR~GY
@:

AlTmodels

:
MITmodels
... :Detectable line
for DTC
---: Non-detectable
line forDTC

C£I)
L

EC-336 HEC015

•IGN TIMING ADJ.
0

TROUBLE
DIAGNOSIS FORNON-DETECTABLE ITEMS
[ill

Idle AirControl Valve(IACV) -Auxiliary Air
Control (AAC)Valve(Cont'd)
DIAGNOSTIC PROCEDURE
-- CONDITION SETIING--
IGN/T FEEDBACK HOLD INSPECTION
START

~i5 ~i5

ECM
E[CONNECTORII
cffb

113

=
= =
MONITOR
CAS. RPM (REF)
IGN TIMING
IDLE POSITION
---
---

800rpm
15BTDC
ON
SEF786KA
MEC768B CHECK
OVERALL FUNCTION.
1. Start engine andwarm itup suffi-
ciently.
2. Check idlespeed.

800::1:50
rpm
If NG, adjust idlespeed. (Referto
(l)
e
EC-243.)
3. .. •Perform "IGNTIMING ADJ"

I!I
in"WORK SUPPORT" mode
with CONSULT.
~ •Disconnect IACV-AACvalve

5
harness connector.
4. Ma esure thatidlespeed drops.
Does notdrop
CHECK POWER SUPPLY.
1. Stop engine.
2. Disconnect IACV-AACvalveharness
connector.
3. Turn ignition switch"ON".
4. Check voltage between terminal
G)

and ground withCONSULT ortester.
Voltage: Batteryvoltage
OK

[!1
CHECK OUTPUT SIGNALCIRCUIT.
1. Disconnect ECMharness connector.
2. Check harness continuity between
ECM terminal
CTID
andterminal
(2).

Continuity shouldexist.
If OK, check harness forshort
OK
CHECK COMPONENT
(IACV-AAC valve).
Refer to"COMPONENT INSPECTION"
on next page.
OK Drops
NG
NG
NG INSPECTION
END
Check thefollowing .
• Harness connectors

@D,
([ill)(M/Tmod-
els)
• Harness connectors

@,
@
(A/T
models)
• 7.5A fuse
• Harness foropen or
short between IACV-
AAC valve harness con-
nector andfuse
If NG, repair harness or
con nectors.
Check thefollowing.
• Harness connectors

@,@D

• Harness foropen or
short between ECMand
IACV-AAC valve

If
NG, repair harness or
connectors.
Replace IACV-AAC valve.
•

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-337

IACV-AACvalve

Disconnect IACV-AACvalveharness connector.
• Check IACV-AAC valveresistance.
Resistance: Approximately 100[at25°C (77°F)]
• Check plunger forseizing orsticking.
• Check forbroken spring.

MEC770B

TROUBLE
DIAGNOSIS FORNON-DETECTABLE ITEMS
[ill

Idle AirControl Valve(IACV) -Auxiliary Air
Control (AAC)Valve(Cont'd)

COMPONENT INSPECTION
EC-338

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
[]K]

Idle AirControl Valve(IACV)-FICD Solenoid
Valve

EC-FICD-01

~
G

1 _
•

Refer
toEL-POWER.

I

L/R

1$l
m
(E202)

L/R

I
Tocompressor
.- L/R
+
(Refer to

I
HA-A/C.)

L/R

~ IACV-

FICO

SOLENOID VALVE

lbi=Jl
CE212)

B

1$1
(E227)

([g)

~ TOECM

• +
(ECCS
- B/Y
contro
1

I
r-J
module)

B/Y
BB

t.J
1

ill)

G
~Next page
FUSE
BLOCK
(JIB)

@
L/Y
(El06)
I

~
LIB L!Y

!~
rn~
AIR

I
~12g~~~TIONER

-I ........~ -I
--~I-~~I
«@

Y L/R

I.
I

~ Y
JA---..
Next
.",........- page
To
A/C
switch
GY
+
(Refer to
HA-A/C. )
THERMO
CONTROL
AMPLIFIER

lMW

OUAL-
PRESSURE
SWITCH

@

~t

LOW HIGH

.... ~r-.

NORMAL
_. Detectable line
for oTC
-: Non-detectable
line foroTC
THERMISTOR

A«@

T
L
~
(E202)

rIDm:IID
B
~
(E212) ~
([g)

UJ.g)
GY~ GY
~~
2 W

3
Refer
tolast page
(Foldout page).

CHID
{EtOn

,

@
(El06)

,

JS2L~

w.g)
B
EC-339 HEC021

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
[]K]

Idle AirControl Valve(IACV)-FICD Solenoid
Valve (Cont'd)

EC-FICD-02

Preceding
page
<@-6

<&Y
-:
Detectable line
for DTC
-: Non-detectable
line forDTC

Y 6

r=bCE101) ~

116Al~ ---- - --- -- ~f38l1

'-T"' eM[)
'T'

Y 6
Y
@
6

II~~-~~-------~rihl
~@
T

t

Y

din

ACRLY
6

rF41i1
AIR ECM
CON (ECCS
CONTROL
MODULE)

em

Refertolast page
(Foldout page).

(MS)

,

EC-340
em

L

HEC022

MEF023D
•

Refer to"TROUBLE
DIAGNOSES"
i!1
HA sec-
tion. INSPECTION
END
Check thefollowing.
• Harness connectors

@D,@!)

• Harness foropen or
short between IACV-
FICO solenoid valve
harness connector and
air conditioner relay
If NG, repair harness or
connectors.

OK
NG
NG
CHECK
OVERALL FUNCTION.

1. Start engine andwarm itup suffi-
ciently.
2. Check idlespeed.

800:1::50
rpm

If NG, adjust idlespeed.
3. Turn airconditioner switchand
blower fanswitch "ON".
4. Recheck idlespeed.

850 rpm ormore

Check ifair conditioner compressor
functions normally.

DIAGNOSTIC
PROCEDURE
OKNG
OK

INSPECTION
START

CHECK POWER SUPPLY.

1. Stop engine.
2. Disconnect IACV-FICDsolenoidvalve
harness connector.
3. Start engine, thenturnairconditioner
switch andblower fan"ON".
4. Check voltage between terminal
CD

and ground withCONSULT ortester.

Voltage: Batteryvoltage
AEC765
MEF634E
TROUBLE
DIAGNOSIS FORNON-DETECTABLE ITEMS
[]liJ

Idle AirControl Valve(IACV)-FICD Solenoid
Valve (Cont'd)
COMPONENT DESCRIPTION

When theairconditioner ison, the IACV-FICD solenoidvalve
supplies additional airtoadjust tothe increased load.
Idle
adjusting
screw

EC-341