1995 NISSAN ALMERA N15 engine coolant

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
Valve Timing Control (VTC)
SYSTEM DESCRIPTION

Mass airflow sensor Amount
ofintake air
Camshaft positionsensor Enginespeed
Engine coolant temperature sensorEnginecoolant temperature ECM

(ECCS

control module) Valve
timing
control solenoid
valve
Throttle positionsensor Throttle
position

The valve timing control system isutilized toincrease engineperformance. Intakevalveopening and
closing timeiscontrolled, accordingtothe engine operating conditions, bythe ECM.
Engine coolant temperature signals,enginespeed,amount ofintake air,throttle position, vehiclespeed
and gear position areused todetermine intakevalvetiming.
The intake camshaft pulleyposition isregulated byoil pressure, whichiscontrolled bythe valve timing
control solenoid valve.

Drain .. Intake
airsignal (From massairflow sensor)
Engine speedsignal(From camshaft positionsensor)
Engine coolant temperature (Fromengine coolant temperature sensor)
Throttle valveidleposition (Fromthrottle position sensor)
Vehicle speed(Fromvehicle speedsensor)
"'- Camshaft (Intakeside)

EGM
(EGGS

control
module)

/

Camshaft sprocket
Piston
Valve
timing control ~
»

'o'""oid ,,',"
Ii

/

Return spring

MEF572DA
EC-198

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
Valve Timing Control (VTC)(Cont'd)
OPERATION
Engine operating condition Valve
timing control Intakevalveopening
Valveoverlap Enginetorquecurve
solenoid valve
andclosing time
• Engine coolant temperature
is 70"C (158"F) ormore .
• Engine loadishigh .
• Engine speedisbetween
ONAdvance
Increased @
1,500 rpmand5,100 rpm.
• Engine speedis6,800 rpmor
more.
Those otherthanabove OFFNormal Normal

CD

CD
Valve timing control (VTC)solenoid valveisOFF. @Valve timing control (VTC)solenoid valveisON.

•

Effr
t
f__ ~

Torque ~

L__ _

Engine speed
--+-

Except forAustralia
Exhaust valve
open time
Intake closes
For Australia
Exhaust valve
open time
intake cioses Intake
valve
open lime
BOC
CD

I~Overlap (-12°)
TOC ,Intake opens
Intake valve
open time Overlap
(18°)
@
BOC
CD

EC-199 @
SEF183R

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS~
Torque Converter ClutchSolenoid Valve(Cont'd)
SYSTEM DESCRIPTION

Throttle position sensor Throttle
valveopening angle
Engine coolant temperature sensorEnginecoolant temperature ECM
(ECCS
control
module) Torque
converter
clutch solenoid
valve
Vehicle speedsensor Vehicle
speed

The
AfT
lock-up iscontrolled bythe ECM through
the torque converter clutchsolenoid valve.When
the ECM detects anyofthe following conditions,
the ECM switches thetorque converter clutch
solenoid valveOFFtoaccomplish lock-upDpera-
tion. While thevehicle isin conditions otherthan
below, thetorque converter clutchsolenoid valve
is always settoON, releasing thelock-up oper-
ation.
•
•
•
Throttle
position isopen .
Engine coolant temperature is60°C (140°F) or•
more.
Vehicle speedis58 kmfh (36MPH) ormore .

m ~
i3~

II
ECM
HCONNECTORII

30 115

ID
cf6~H

~i3~

II
ECM E
CONNECTOR
II

30 115

iIJ
ID
cf6~H

@> :
AIT
models forAustralia

@:
AlTmodels exceptforEurope
and Israel, andAustralia
SEF189RDIAGNOSTIC
PROCEDURE

INSPECTION START
CHECK CONTROL FUNCTION.
1. Jack updrive wheels.
2. Start engine andwarm itup suffi-
ciently.
3. Shift selector leverto"D" position.
4. Check voltage between ECMterminal

GID
or
@
and ground underthe
following conditions.

Voltage: Accelerator pedalisdepressed
[Vehicle speedisabove

58 km/h (36MPH).]

Battery voltage
Accelerator pedalisfully
released ApprOXimately OV
OK

CHECK COMPONENT
(Torque converter clutch
solenoid valve).
Refer to"Electrical Com-
ponents Inspection" in
AT section.
If NG, replace torque
converter clutchsolenoid
valve.

OK

INSPECTION END

MEC279BA NG
EC-221

ENGINEANDEMISSION CONTROLOVERALLSYSTEM
ECCS Component PartsLocation
EGR valve
IACV.air regulator
EGRC-BPTvalve
Injector
IACV.AAC valve
IACV.FICD solenoidvalve
Engine coolant temperature sensor
Knock sensor Pressure
regulator
Heated oxygen
sensor Camshaft
positionsensor,
ignition coiland power
transistor builtintodistributor
EC-228
SEF307R

ENGINEANDEMISSION CONTROL OVERALLSYSTEM ~
ECCS Component PartsLocation (Cont'd)
Engine coolant temperature sensor
IACV.FICD solenoidvalve
•

IACV.air regulator
Knock sensor
SEF308R
EC-229

ENGINEANDEMISSION CONTROLOVERALLSYSTEM
System Chart

Camshaft positionsensor Fuel

injection
&
mixture ratio
•
I

I
control Injectors
Mass airflow sensor

I

Distributorignitionsystem

r
~1
Power transistor
Engine coolant temperature
.

sensor

I
IACV-AAC valveand
Idle aircontrol system
IACV-FICDsolenoidvalve
Heated oxygen sensor

I

IACV-airregulator control

~--..j
IACV-air regulator

I

Ignition switch

I

I
Throttle position sensor

~-+
Fuel
pump control Fuel
pump relay
ECM
(ECCS
control
Neutral position/Inhibitor
.

module) Heatedoxygen sensor
switch monitor
&
on-board diagnos-
~-+
Malfunction
indicatorlamp
tic system (On
theinstrument panel)

I
Air conditioner switch

t~

EGRvalve
&
EVAP canister

1---+
EGR
valve
&
EVAP canister
purge control purge
control solenoid valve
Knock sensor

.....

Frontheated oxygen sensor Front
heated oxygen sensor
Battery voltage
.
heater
control heater

I
.

Power steering oilpressure

~

Coolingfancontrol

--
Cooling
fanrelay
switch
Vehicle speedsensor
.....

Airconditioning cutcontrol Air
conditioner relay

EC-232

ENGINEANDEMISSION BASICCONTROL SYSTEMDESCRIPTION
Multiport FuelInjection (MFI)System
INPUT/OUTPUT SIGNALLINE

Camshaft positionsensor
Mass airflow sensor
Engine coolant temperature sensor
Front heated oxygen sensor
Throttle position sensor
Neutral position/lnhibitor switch

I
Vehicle speedsensor
Ignition switch
Air conditioner switch
Battery Engine
speedandpiston position
Amount ofintake air
Engine coolant temperature
Density ofoxygen inexhaust gas
Throttle position
Throttle valveidleposition
Gear position

I
Vehicle speed
Start signal
Air conditioner operation
Battery voltage ECM
(ECCS
control
module) Injector
•

BASIC MULTIPORT FUELINJECTION
SYSTEM

The amount offuel injected fromthefuel injector
is determined bythe ECM. TheECM controls the
length oftime thevalve remains open(injection
pulse duration). Theamount offuel injected isa
program valueinthe ECM memory. Theprogram
value ispreset byengine operating conditions.
These conditions aredetermined byinput signals
(for engine speedandintake air)from boththe
camshaft positionsensorandthemass airflow
sensor.
VARIOUS
FUELINJECTION
INCREASE/DECREASE COMPENSATION

In addition, theamount offuel injected iscom-
pensated toimprove engineperformance under
various operating conditions aslisted below.

<
Fuel increase>
• During warm-up
• When starting theengine
• During acceleration
• Hot-engine operation
• When selector leverischanged from"N"to
"0" (AfT models only)
• High-load operation

<
Fuel decrease>
• During deceleration

EC-233

ENGINEANDEMISSION BASICCONTROL SYSTEMDESCRIPTION [][]
Multiport FuelInjection (MFI)System (Cont'd)
CLOSED LOOP MIXTURERATIOFEEDBACK CONTROL(CLOSEDLOOP
CONTROL CONTROL)

The mixture ratiofeedback systemprovides thebest air-fuel

Feedback signal
mixtureratiofordriveability andemission control.Thethree
way catalyst canthen better reduce CO,HCand NOx emissions.
This system usesaheated oxygen sensorinthe exhaust man-
ifold tomonitor ifthe engine operation isrich orlean. TheECM
adjusts theinjection pulsewidthaccording tothe sensor volt-
age signal. Formore information abouttheheated oxygen
sensor, refertoEC-362. Thismaintains themixture ratiowithin

MEF025DD
therange ofstoichiometric (idealair-fuel mixture).
This stage isreferred toas the closed loopcontrol condition.

OPEN LOOPCONTROL

The open loopsystem condition referstowhen theECM detects
any ofthe following conditions. Feedbackcontrolstopsinorder
to maintain stabilized fuelcombustion.
• Deceleration andacceleration
• High-load, high-speed operation
• Engine idling
• Malfunction ofheated oxygen sensororits circuit
• Insufficient activationofheated oxygen sensoratlow
engine coolant temperature
• High-engine coolanttemperature
• After shifting from"N"to"0"
• During warm-up
• When starting theengine

MIXTURE RATIOSELF-LEARNING CONTROL

The mixture ratiofeedback controlsystem monitors themixture
ratio signal transmitted fromtheheated oxygen sensor. This
feedback signalisthen senttothe ECM. TheECM controls the
basic mixture ratioasclose tothe theoretical mixtureratioas
possible. However, thebasic mixture ratioisnot necessarily con-
trolled asoriginally designed. Bothmanufacturing differences
(Le., mass airflow sensor hotwire) andcharacteristic changes
during operation (Le.,injector clogging) directlyaffectmixture
ratio.
Accordingly, thedifference betweenthebasic andtheoretical
mixture ratiosismonitored inthis system. Thisisthen com-
puted interms of"injection pulseduration" toautomatically
compensate forthe difference betweenthetwo ratios.

EC-234