Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
IGN TIMING [BTDC]j+Indicates the ignition timing computed by
ECM according to the input signals.
CAL/LD VALUE [%]+ªCalculated load valueº indicates the value
of the current airflow divided by peak air-
flow.
ABSOL TH.P/S [%]+ªAbsolute throttle position sensorº indicates
the throttle opening computed by ECM
according to the signal voltage of the
throttle position sensor.
MASS AIRFLOW
[gm/s]+Indicates the mass airflow computed by
ECM according to the signal voltage of the
mass air flow sensor.
IACV-AAC/V [step]j+Indicates the IACV-AAC valve control value
computed by ECM according to the input
signals.
PURG VOL C/V [%]+Indicates the EVAP canister purge volume
control solenoid valve computed by the
ECM according to the inpuct signals.
+The opening becomes larger as the value
increases.
EGR VOL CON/V
[step]*j+Indicates the EGR volume control valve
computed by the ECM according to the
input signals.
+The opening becomes larger as the value
increases.
SWRL CONT S/V
[ON/OFF]*+The control condition of the swirl control
valve control solenoid valve (determined by
ECM according to the input signals) is indi-
cated.
+ON ... Swirl control valve is closed.
OFF ... Swirl control valve is opened.
INT/V SOL-B1
[ON/OFF]+The control condition of the valve timing
solenoid valve (determined by ECM accord-
ing to the input signal) is indicated.
ON ... Intake valve timing control operating
OFF ... Intake valve timing control not oper-
ating
AIR COND RLY
[ON/OFF]j+Indicates the air conditioner relay control
condition determined by ECM according to
the input signals.
FUEL PUMP RLY
[ON/OFF]j+Indicates the fuel pump relay control condi-
tion determined by ECM according to the
input signals.
COOLING FAN
[ON/OFF]j+Indicates [ON/OFF] control condition of the
cooling fan determined by ECM according
to the input signals.
HO2S1 HTR (B1)
[ON/OFF]+Indicates [ON/OFF] condition of heated oxy-
gen sensor 1 heater (front) determined by
ECM according to the input signals.
HO2S2 HTR (B1)
[ON/OFF]+Indicates [ON/OFF] condition of heated oxy-
gen sensor 2 heater (rear) determined by
ECM according to the input signals.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
CONSULT-II (Cont'd)
EC-89
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
IDL A/V LEARN+Display the condition of idle air volume
learning
YET ... Idle air volume learning has not
been performed yet.
CMPLT ... Idle air volume learning has
already been performed successfully.
INCMP ... Idle air volume learning has not
been performed successfully.
TRVL AFTER MIL
[km] or [Mile]+Distance traveled while MI is activated
VOLTAGE [V]+Voltage measured by the voltage probe.
PULSE
[msec] or [Hz] or [%]+Pulse width, frequency or duty cycle mea-
sured by the pulse probe.+Only ª#º is displayed if item is
unable to be measured.
+Figures with ª#ºs are temporary
ones. They are the same figures as
an actual piece of data which was
just previously measured.
*: If so equipped
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
DATA MONITOR (SPEC) MODENJEC0034S11
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
MAS A/F SE-B1 [V]jj+The signal voltage of the mass air flow sen-
sor specification is displayed.+When the engine is running, speci-
fication range is indicated.
B/FUEL SCHDL
[msec]+ªBase fuel scheduleº indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board correc-
tion.+When the engine is running, speci-
fication range is indicated.
A/F ALPHA-B1 [%]j+Indicates the mean value of the air-fuel
ratio feedback correction factor per cycle.+When the engine is running, speci-
fication range is indicated.
+This data also includes the data for
the air-fuel ratio learning control.
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODENJEC0034S07
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJECTION+Engine: Return to the original
trouble condition
+Change the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.+Harness and connector
+Fuel injectors
+Heated oxygen sensor 1 (front)
IGNITION TIMING+Engine: Return to the original
trouble condition
+Timing light: Set
+Retard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.+ªIdle Air Volume Leaningº (Refer
to EC-57.)
+Camshaft position sensor
(PHASE)
+Crankshaft position sensor
(POS)
+Engine component parts and
installing conditions
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
CONSULT-II (Cont'd)
EC-90
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
IACV-AAC/V
OPENING+Engine: After warming up, idle
the engine.
+Change the IACV-AAC valve
opening steps using CONSULT-
II.Engine speed changes according
to the opening steps.+Harness and connector
+IACV-AAC valve
POWER BAL-
ANCE+Engine: After warming up, idle
the engine.
+Air conditioner switch ªOFFº
+Shift lever ªNº
+Cut off each injector signal one
at a time using CONSULT-II.Engine runs rough or dies.+Harness and connector
+Compression
+Injectors
+Power transistor
+Spark plugs
+Ignition coils
COOLING FAN+Ignition switch: ON
+Turn the cooling fan ªONº and
ªOFFº using CONSULT-II.Cooling fan moves and stops.+Harness and connector
+Cooling fan motor
ENG COOLANT
TEMP+Engine: Return to the original
trouble condition
+Change the engine coolant tem-
perature indication using CON-
SULT-II.If trouble symptom disappears, see
CHECK ITEM.+Harness and connector
+Engine coolant temperature sen-
sor
+Fuel injectors
FUEL PUMP
RELAY+Ignition switch: ON
(Engine stopped)
+Turn the fuel pump relay ªONº
and ªOFFº using CONSULT-II
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.+Harness and connector
+Fuel pump relay
EGR VOL
CONT/V
(If so equipped)+Engine: After warming up, idle
the engine.
+Change the EGR volume control
valve opening step using CON-
SULT-II.Engine speed changes according
to the opening step.+Harness and connector
+EGR volume control valve
VALVE TIMING
SOL+Ignition switch: ON
+Turn intake valve timing control
solenoid valve ªONº and ªOFFº
using CONSULT-II and listen for
operating sound.Intake valve timing control solenoid
valve makes an operating sound.+Harness and connector
+Intake valve timing control sole-
noid valve
SWIRL CONT
S O L VA LV E
(If so equipped)+Ignition switch: ON
+Turn solenoid valve ªONº and
ªOFFº with CONSULT-II and lis-
ten for operating sound.Solenoid valve makes an operating
sound.+Harness and connector
+Solenoid valve
PURG VOL
CONT/V+Engine: After warming up, idle
the engine.
+Change the EVAP canister
purge volume control solenoid
valve opening percent using
CONSULT-II.Engine speed changes according
to the opening percent.+Harness and connector
+EVAP canister purge volume
control solenoid valve
DTC AND SRT CONFIRMATION MODENJEC0034S08This mode is not available for models without Euro-OBD system.
SRT STATUS ModeNJEC0034S0801For details, refer to ªSYSTEM READINESS TEST (SRT) CODEº,
EC-62.
SRT Work Support ModeNJEC0034S0803This mode enables a technician to drive a vehicle to set the SRT
while monitoring the SRT status.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
CONSULT-II (Cont'd)
EC-91
SEF139P
Generic Scan Tool (GST)=NJEC0035DESCRIPTIONNJEC0035S01Generic Scan Tool (OBDII scan tool) complying with ISO15031-4
has 9 different functions explained on the next page.
ISO9141 is used as the protocol.
The name ªGSTº or ªGeneric Scan Toolº is used in this service
manual.
SEF094Y
GST INSPECTION PROCEDURENJEC0035S021. Turn ignition switch OFF.
2. Connect ªGSTº to data link connector. (Data link connector is
located under lower dash panel near the fuse box cover.)
SEF398S
3. Turn ignition switch ON.
4. Enter the program according to instruction on the screen or in
the operation manual.
(*: Regarding GST screens in this section, sample screens are
shown.)
SEF416S
5. Perform each diagnostic mode according to each service pro-
cedure.
For further information, see the GST Operation Manual of the
tool maker.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
Generic Scan Tool (GST)
EC-94
MEF036D
SEF233G
SEF234G
IntroductionNJEC0036The 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 actuators.
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 intermit-
tently 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-II (or GST) or a circuit tester connected should
be performed. Follow the ªWork Flowº on EC-98.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such problems, espe-
cially intermittent ones. Find out what symptoms are present and
under what conditions they occur. A ªDiagnostic Worksheetº like the
example on next page should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
SEF907L
DIAGNOSTIC WORKSHEETNJEC0036S01There are many operating conditions that lead to the malfunction
of engine components. A good grasp of such conditions can make
trouble-shooting faster and more accurate.
In general, each customer feels differently about a problem. It is
important to fully understand the symptoms or conditions for a
customer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the malfunction indicator lamp to
come on steady or blink and DTC to be detected.
Example:
Vehicle ran out of fuel, which caused the engine to misfire.
TROUBLE DIAGNOSIS Ð INTRODUCTIONQG
EC-96
23 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 625±50 rpm
A/T: 700±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 29.
NG (Models with Euro-
OBD system)©GO TO 25.
NG (Models without
Euro-OBD system)©GO TO 24.
24 CHECK IACV-AAC VALVE CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check IACV-AAC valve circuit for open and short. Refer to ªDiagnostic Procedureº, EC-380.
OK or NG
OK©GO TO 25.
NG©1. Repair or replace.
2. GO TO 26.
25 REPLACE IACV-AAC VALVE
Replace IACV-AAC valve.
©GO TO 26.
26 PERFORM IDLE AIR VOLUME LEARNING
Refer to ªIdle Air Volume Learningº, EC-57.
Which is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©GO TO 27.
INCMP©1. Follow the construction of ªIdle Air Volume Learningº.
2. GO TO 22.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Sedan (Cont'd)
EC-112
27 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 29.
NG©GO TO 28.
28 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of a problem, but this is rarely
the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-74.
©GO TO 22.
29 CHECK IGNITION TIMING
1. Start engine and warm it up to normal operating temperature.
2. Check ignition timing at idle using a timing light.
SEF984U
Ignition timing:
M/T 8ɱ5É BTDC
A/T 10ɱ5É BTDC (in ªPº or ªNº position)
OK or NG
OK©GO TO 37.
NG©GO TO 30.
30 CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-28, ªInstallationº.
OK or NG
OK©GO TO 28.
NG©1. Repair the timing chain installation.
2. GO TO 22.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Sedan (Cont'd)
EC-113
31 CHECK IGNITION TIMING
1. Start engine and let it idle.
2. Check ignition timing at idle using a timing light.
SEF984U
Ignition timing:
M/T 8ɱ5É BTDC
A/T 10ɱ5É BTDC (in ªPº or ªNº position)
OK or NG
OK©GO TO 37.
NG©GO TO 22.
32 PERFORM IDLE AIR VOLUME LEARNING
Refer to ªIdle Air Volume Learningº, EC-57.
Which is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©GO TO 33.
INCMP©1. Follow the construction of ªIdle Air volume Learningº.
2. GO TO 32.
33 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 35.
NG©GO TO 34.
34 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function.
(ECM may be the cause of a problem, but this is rarely the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-74.
©GO TO 32.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Sedan (Cont'd)
EC-114