1998 NISSAN PICK-UP check engine

HOW TO SWITCH DIAGNOSTIC TEST MODES (LHD models)
Turn ignition switch ``ON''.
(Do not start engine.)
c
Diagnostic Test Mode I Ð BULB
CHECK. Refer to previous page.
MIL should come on.
OK
cNGCheck MIL circuit.
(See EC-173.)
OK
cNG
Repair harness or
connectors.
b
cG
Start engine.
cDiagnostic Test
Mode I
Ð MALFUNC-
TION WARN-
ING.
Refer to previ-
ous page.
Data link connector for CONSULT
(Connect CHK and IGN terminals with a
suitable harness.)
MIL should go off.
OK
cNG
Check MIL circuit and data link connector for
CONSULT circuit. (See EC-173.)
OK NG
Check ECM fail-
safe.
(See EC-61.)
Repair harness or
connectors.
OK
Wait at least 2 seconds.
b
Data link connector for CONSULT
(Disconnect the suitable harness
between CHK and IGN terminals.)
DIAGNOSTIC TEST MODE II
Ð SELF-DIAGNOSTIC RESULTScG
Start engine.
cDiagnostic Test
Mode II
Ð HEATED
OXYGEN
SENSOR
MONITOR
VBVA
.
.
..
.
.
.
.
.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONKA
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-39

HOW TO SWITCH DIAGNOSTIC TEST MODES (RHD models)
Turn ignition switch ``ON''. (Do not
start engine.)
cDiagnostic Test Mode I Ð BULB CHECK.
Refer to previous page.
MIL should come on.
OK
cNGCheck MIL cir-
cuit.
(See EC-174.)
OK
cNG
Repair harness
or connectors.
bYes
Check whether
ECM test mode
selector can be
turned counter-
clockwise.cNo
Repair or
replace ECM
test mode
selector.
cG
Start engine.
cDiagnostic Test
Mode I
Ð MALFUNC-
TION
WARNING.
Refer to pre-
vious page.
Data link connector for CONSULT
(Connect CHK and IGN terminals
with a suitable harness.)
MIL should go off. (Turn diagnostic test mode
selector on ECM fully clockwise.)
MIL should go off.or
OK
cNG
Check MIL circuit and data link connector
for CONSULT circuit. (See EC-174.)
OK NG
Check ECM
fail-safe.
(See EC-61.)
OKRepair harness
or connectors.OK
Wait at least 2 seconds.
b
Data link connector for CONSULT
(Disconnect the suitable harness
between CHK and IGN terminals.) (Turn diagnostic test mode
selector fully counterclockwise.)or
DIAGNOSTIC TEST MODE II
Ð SELF-DIAGNOSTIC RESULTS
VBVA
.
.
.
..
.
.
.
.
.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONKA
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-41

DIAGNOSTIC TEST MODE IIÐHEATED OXYGEN SENSOR MONITOR
In this mode, the MALFUNCTION INDICATOR LAMP displays the condition of the fuel mixture (lean or rich)
which is monitored by the heated oxygen sensor.
MALFUNCTION INDICATOR LAMP Fuel mixture condition in the exhaust gasAir fuel ratio feedback control
condition
ON Lean
Closed loop control
OFF Rich
*Remains ON or OFF Any condition Open loop control
*: Maintains conditions just before switching to open loop.
To check the heated oxygen sensor function, start engine in the Diagnostic Test Mode II and warm it up
until engine coolant temperature indicator points to the middle of the gauge.
Next run engine at about 2,000 rpm for about 2 minutes under no-load conditions. Then make sure that the
MALFUNCTION INDICATOR LAMP comes ON more than 5 times every 10 seconds when measured at
2,000 rpm under no-load.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONKA
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-44

FUNCTION
Diagnostic test mode Function
Work supportA technician can adjust some devices faster
and more accurately by following indications
on CONSULT.
Self-diagnostic resultsSelf-diagnostic results can be read and
erased quickly.
Data monitor Input/Output data in the ECM can be read.
Active testCONSULT drives some actuators apart from
the ECM's and also shifts some parameters in
a specified range.
Function testConducted by CONSULT instead of a techni-
cian to determine whether each system is
``OK'' or ``NG''.
ECM part number ECM part number can be read.
WORK SUPPORT MODE
WORK ITEM CONDITION USAGE
THRTL POS SEN ADJ CHECK THE THROTTLE POSITION SENSOR SIGNAL.
ADJUST IT TO THE SPECIFIED VALUE BY ROTATING
THE SENSOR BODY UNDER THE FOLLOWING CONDI-
TIONS.
lIGN SW ``ON''
lENG NOT RUNNING
lACC PEDAL NOT PRESSEDWhen adjusting throttle position
sensor initial position
IGNITION TIMING ADJ
lIGNITION TIMING FEEDBACK CONTROL WILL BE
HELD BY TOUCHING ``START''. AFTER DOING SO,
ADJUST IGNITION TIMING WITH A TIMING LIGHT BY
TURNING THE CRANKSHAFT POSITION SENSOR.When adjusting initial ignition
timing
IACV-AAC VALVE ADJ SET ENGINE SPEED AT THE SPECIFIED VALUE
UNDER THE FOLLOWING CONDITIONS.
lENGINE WARMED UP
lNO-LOAD
FUEL PRESSURE RELEASE
lFUEL PUMP WILL STOP BY TOUCHING ``START''
DURING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS.When releasing fuel pressure
from fuel line
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONKA
CONSULT (Cont'd)
EC-46

ACTIVE TEST MODE
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJECTION
lEngine: Return to the original trouble
condition
lChange the amount of fuel injection
using CONSULT.If trouble symptom disappears, see
CHECK ITEM.
lHarness and connectorlFuel injectorslHeated oxygen sensor
IACV-AAC/V
OPENING
lEngine: After warming up, idle the
engine.
lChange the IACV-AAC valve opening
percent using CONSULT.Engine speed changes according to the
opening percent.lHarness and connectorlIACV-AAC valve
ENG COOLANT
TEMP
lEngine: Return to the original trouble
condition
lChange the engine coolant
temperature using CONSULT.If trouble symptom disappears, see
CHECK ITEM.
lHarness and connectorlEngine coolant temperature sensorlFuel injectors
IGNITION TIMING
lEngine: Return to the original trouble
condition
lTiming light: SetlRetard the ignition timing using
CONSULT.If trouble symptom disappears, see
CHECK ITEM.
lAdjust ignition timing (by moving
camshaft position sensor)
POWER BALANCE
lEngine: After warming up, idle the
engine.
lA/C switch ``OFF''lShift lever ``N''lCut off each injector signal one at a
time using CONSULT.Engine runs rough or dies.
lHarness and connectorlCompressionlInjectorslIgnition coil with power transistorlSpark plugs
FUEL PUMP RELAY
lIgnition switch: ON (Engine stopped)lTurn the fuel pump relay ``ON'' and
``OFF'' using CONSULT and listen to
operating sound.Fuel pump relay makes the operating
sound.lHarness and connectorlFuel pump relay
EGRC SOLENOID
VALVE
(EVAP canister
purge control
solenoid valve)
lIgnition switch: ONlTurn solenoid valve ``ON'' and ``OFF''
with CONSULT and listen to
operating sound.Solenoid valve makes an operating
sound.lHarness and connectorlEVAP canister purge control solenoid
valve
SWIRL CONT SOL
VALVE
lIgnition switch: ON (Engine stopped)lTurn solenoid valve ``ON'' and ``OFF''
with CONSULT and listen to
operating sound.Solenoid valve makes an operating
sound.lHarness and connectorlSwirl control valve control solenoid
valve
SELF-LEARNING
CONT
lIn this test, the coefficient of self-learning control mixture ratio returns to the original coefficient by touching ``CLEAR'' on the
screen.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONKA
CONSULT (Cont'd)
EC-50

FUNCTION TEST MODE
FUNCTION TEST
ITEMCONDITION JUDGEMENT CHECK ITEM (REMEDY)
SELF-DIAG
RESULTS
lIgnition switch: ON
(Engine stopped)
lDisplays the results of on board
diagnostic system.Ð Objective system
CLOSED THROTTLE
POSI
lIgnition switch: ON
(Engine stopped)
lThrottle position sensor circuit is
tested when throttle is opened
and closed fully. (``IDLE
POSITION'' is the test item name
for the vehicles in which idle is
selected by throttle position
sensor.)Throttle valve:
openedOFF
lHarness and connector
lThrottle position sensor (Closed
throttle position)
lThrottle position sensor (Closed
throttle position) adjustment
lThrottle linkage
lVerify operation in DATA
MONITOR mode. Throttle valve:
closedON
THROTTLE POSI
SEN CKT
lIgnition switch: ON
(Engine stopped)
lThrottle position sensor circuit is
tested when throttle is opened
and closed fully.Range (Throttle
valve fully opened
Ð Throttle valve
fully closed)More than
3.0V
lHarness and connector
lThrottle position sensor
lThrottle position sensor
adjustment
lThrottle linkage
lVerify operation in DATA
MONITOR mode.
PARK/NEUT POSI
SW CKT
lIgnition switch: ON
(Engine stopped)
lNeutral position switch circuit is
tested when shift lever is
manipulated.Out of N/P
positionsOFF
lHarness and connector
lNeutral position switch
lLinkage adjustment
In N/P positions ON
FUEL PUMP
CIRCUIT
lIgnition switch: ON
(Engine stopped)
lFuel pump circuit is tested by
checking the pulsation in fuel
pressure when fuel tube is
pinched.There is pressure pulsation on
the fuel feed hose.
lHarness and connector
lFuel pump
lFuel pump relay
lFuel filter clogging
lFuel level
EGRC SOL/V
CIRCUIT
(EVAP canister purge
control solenoid valve
circuit)
lIgnition switch: ON
(Engine stopped)
lEVAP canister purge control
solenoid valve circuit is tested by
checking solenoid valve operating
noise.The solenoid valve makes an
operating sound every 3
seconds.lHarness and connector
lEVAP canister purge control
solenoid valve
START SIGNAL
CIRCUIT
lIgnition switch: ON®START
lStart signal circuit is tested when
engine is started by operating the
starter. Battery voltage and water
temperature before cranking, and
average battery voltage, mass air
flow sensor output voltage and
cranking speed during cranking
are displayed.Start signal: OFF®ON
lHarness and connector
lIgnition switch
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONKA
CONSULT (Cont'd)
EC-51

FUNCTION TEST
ITEMCONDITION JUDGEMENT CHECK ITEM (REMEDY)
PW/ST SIGNAL
CIRCUIT
lIgnition switch: ON
(Engine running)
lPower steering oil pressure switch
circuit is tested when steering
wheel is rotated fully and then set
to a straight line running position.Locked position ONlHarness and connector
lPower steering oil pressure switch
lPower steering oil pump
Neutral position OFF
SWRL CONT S/V
CIRCUIT
lIgnition switch: ON
(Engine stopped)
lSwirl control valve control sole-
noid valve circuit is tested by
checking solenoid valve operating
sound.The solenoid valve makes an
operating sound every 3 sec-
onds.
lHarness and connector
lSolenoid valve
lSwirl control valve
lVacuum hose
VEHICLE SPEED
SEN CKT
lVehicle speed sensor circuit is
tested when vehicle is running at
a speed of 10 km/h (6 MPH) or
higher.Vehicle speed sensor input
signal is greater than 4 km/h
(2 MPH).lHarness and connector
lVehicle speed sensor
lSpeedometer
IGN TIMING ADJ
lAfter warming up, idle the engine.
lIgnition timing is checked by read-
ing ignition timing with a timing
light and checking whether it
agrees with specifications.The timing light indicates the
same value on the screen.
lAdjust ignition timing (by moving
camshaft position sensor or
distributor)
lCamshaft position sensor drive
mechanism
MIXTURE RATIO
TEST
lAir-fuel ratio feedback circuit
(injection system, ignition system,
vacuum system, etc.) is tested by
examining the heated oxygen
sensor output at 2,000 rpm under
non-loaded state.Heated oxygen sensor
COUNT: More than 5 times
during 10 seconds
lINJECTION SYS (Injector, fuel
pressure regulator, harness or
connector)
lIGNITION SYS (Spark plug,
ignition coil, power transistor
harness or connector)
lVACUUM SYS (Intake air leaks)
lHeated oxygen sensor circuit
lHeated oxygen sensor operation
lFuel pressure high or low
lMass air flow sensor
POWER BALANCE
lAfter warming up, idle the engine.
lInjector operation of each cylinder
is stopped one after another, and
resultant change in engine rota-
tion is examined to evaluate com-
bustion of each cylinder. (This is
only displayed for models where a
sequential multiport fuel injection
system is used.)Difference in engine speed is
greater than 25 rpm before
and after cutting off the injec-
tor of each cylinder.lInjector circuit (Injector, harness
or connector)
lIgnition circuit (Spark plug, igni-
tion coil, power transistor harness
or connector)
lCompression
lValve timing
IACV-AAC/V
SYSTEM
lAfter warming up, idle the engine.
lIACV-AAC valve system is tested
by detecting change in engine
speed when IACV-AAC valve
opening is changed to 0%, 20%
and 80%.Difference in engine speed is
greater than 150 rpm between
when valve opening is at 80%
and at 20%.
lHarness and connector
lIACV-AAC valve
lAir passage restriction between
air inlet and IACV-AAC valve
lIAS (Idle adjusting screw) adjust-
ment
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONKA
CONSULT (Cont'd)
EC-52

Introduction
The engine has an ECM to control major systems such as fuel
control, ignition control, idle air control system, etc. The ECM
accepts input signals from sensors and instantly drives actua-
tors. It is essential that both input and output signals are proper
and stable. At the same time, it is important that there are no
problems such as vacuum leaks, fouled spark plugs, or other
problems with the engine.
It is much more difficult to diagnose a problem that occurs inter-
mittently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this
case, careful checking of suspected circuits may help prevent the
replacement of good parts.
A visual check only may not find the cause of the problems. A
road test with CONSULT or a circuit tester connected should be
performed. Follow the ``Work Flow'' on EC-56.
Before undertaking actual checks, take just a few minutes to talk
with a customer who approaches with a driveability complaint.
The customer can supply good information about such problems,
especially intermittent ones. Find out what symptoms are present
and under what conditions they occur. A ``Diagnostic Worksheet''
like the example on next page should be used.
Start your diagnosis by looking for ``conventional'' problems first.
This will help troubleshoot driveability problems on an electroni-
cally controlled engine vehicle.
Diagnostic Worksheet
There are many operating conditions that lead to the malfunc-
tions of engine components. A good knowledge of such condi-
tions can make troubleshooting faster and more accurate.
In general, each customer may feel differently about a given
problem. It is important to fully understand the symptoms or
conditions for a customer complaint.
Utilize a diagnostic worksheet like the one on next page in order
to organize all the information for troubleshooting.
MEF036D
SEF233G
SEF234G
SEF907L
TROUBLE DIAGNOSIS Ð IntroductionKA
EC-54