2. Select Mode 4 with GST (Generic Scan Tool).
The emission-related diagnostic information can be erased by selecting Mode 4 with GST (Generic Scan Tool).
How to Erase DTC (No Tools)NCEC0031S06031. If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
9 seconds and then turn it ªONº again.
2. Change the diagnostic test mode from Mode II to Mode I by using the data link connector. (See EC-QG-
48.)
The emission-related diagnostic information can be erased by changing the diagnostic test mode from Diag-
nostic Test Mode II to Mode I by using the data link connector. (Refer to EC-QG-48.)
NOTE:
IIf the battery is disconnected, the emission-related diagnostic information will be lost after approx.
24 hours.
IErasing the emission-related diagnostic information using CONSULT-II or GST is easier and
quicker than switching the mode using the data link connector.
IThe following data are cleared when the ECM memory is erased.
1) Diagnostic trouble codes
2) 1st trip diagnostic trouble codes
3) Freeze frame data
4) 1st trip freeze frame data
5) System readiness test (SRT) codes
6) Test values
7) Distance traveled while MI is activated
8) Others
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but
all of the data listed above, are cleared from the ECM memory during work procedures.
Malfunction Indicator (MI)
NATS (Nissan Anti-Theft System)
IIf the security indicator lights up with the ignition switch in the ªONº position or ªNATS MALFUNC-
TIONº is displayed on ªSELF-DIAG RESULTSº screen, perform self-diagnostic results mode with
CONSULT-II using NATS program card. Refer to ªNATS (Nissan Anti-Theft System)º in EL section.
IConfirm no self-diagnostic results of NATS is displayed before touching ªERASEº in ªSELF-DIAG
RESULTSº mode with CONSULT-II.
IWhen replacing ECM, initialization of NATS system and registration of all NATS ignition key IDs
must be carried out with CONSULT-II using NATS program card.
Therefore, be sure to receive all keys from vehicle owner. Regarding the procedures of NATS ini-
tialization and NATS ignition key ID registration, refer to CONSULT-II operation manual, NATS.
SEF543X
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG16I18DE
Emission-related Diagnostic Information (Cont'd)
EC-45
DESCRIPTIONNCEC0032
The MI is located on the instrument panel.
1. The MI will light up when the ignition switch is turned ON without the engine running. This is a bulb check.
IIf the MI does not light up, refer to EL section (ªWARNING LAMPSº) or see EC-QG-354.
2. When the engine is started, the MI should go off.
If the MI remains on, the on board diagnostic system has detected an engine system malfunction.
On Board Diagnostic System Function=NCEC0032S01The on board diagnostic system has the following four functions.
Diagnostic Test Mode I
1. BULB CHECK:
This function checks the MI bulb for damage (blown, open circuit, etc.).
If the MI does not come on, check MI circuit and ECM test mode selector. (See the following page.)
2. MALFUNCTION WARNING:
This is a usual driving condition. When a malfunction is detected twice in two consecutive driving cycles
(two trip detection logic), the MI will light up to inform the driver that a malfunction has been detected.
The following malfunctions will light up or blink the MI in the 1st trip.
IªMisfire (Possible three way catalyst damage)º
IFail-safe mode
Diagnostic Test Mode II
3. SELF-DIAGNOSTIC RESULTS:
This function allows DTCs and 1st trip DTCs to be read.
4. HEATED OXYGEN SENSOR 1 (FRONT) MONITOR:
This function allows the fuel mixture condition (lean or rich), monitored by heated oxygen sensor 1 (front),
to be read.
MI Flashing without DTC
NCEC0032S0101If the ECM is in Diagnostic Test Mode II, MI may flash when engine is running. In this case, check ECM test
mode selector following ªHOW TO SWITCH DIAGNOSTIC TEST MODESº.
How to switch the diagnostic test (function) modes, and details of the above functions are described later.
(Refer to EC-QG-48.)
SAT652J
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG16I18DE
Malfunction Indicator (MI) (Cont'd)
EC-46
RELATIONSHIP BETWEEN MI, DTC, 1ST TRIP DTC AND DRIVING PATTERNS FOR
ªMISFIREº
NCEC0033S03
*1: When the same malfunction is
detected in two consecutive trips,
MI will light up.
*2: MI will go off after vehicle is driven
3 times (pattern B) without any
malfunctions.
*3: When the same malfunction is
detected in two consecutive trips,
the DTC and the freeze frame
data will be stored in ECM.
*4: The DTC and the freeze framedata will not be displayed any
longer after vehicle is driven 80
times (pattern C) without the same
malfunction.
(The DTC and the freeze frame
data still remain in ECM.)
*5: When a malfunction is detected
for the first time, the 1st trip DTC
and the 1st trip freeze frame data
will be stored in ECM.
*6: The 1st trip DTC and the 1st tripfreeze frame data will be cleared
at the moment OK is detected.
*7: When the same malfunction is
detected in the 2nd trip, the 1st
trip freeze frame data will be
cleared.
*8: 1st trip DTC will be cleared when
vehicle is driven once (pattern C)
without the same malfunction after
DTC is stored in ECM.
SEF392S
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG16I18DE
OBD System Operation Chart (Cont'd)
EC-51
RELATIONSHIP BETWEEN MI, DTC, 1ST TRIP DTC AND DRIVING PATTERNS EXCEPTFOR
ªMISFIRE
NCEC0033S05
*1: When the same malfunction is
detected in two consecutive trips,
MI will light up.
*2: MI will go off after vehicle is driven
3 times (pattern B) without any
malfunctions.
*3: When the same malfunction is
detected in two consecutive trips,
the DTC and the freeze frame
data will be stored in ECM.*4: The DTC and the freeze frame
data will not be displayed any
longer after vehicle is driven 40
times (pattern A) without the same
malfunction.
(The DTC and the freeze frame
data still remain in ECM.)
*5: When a malfunction is detected
for the first time, the 1st trip DTCand the 1st trip freeze frame data
will be stored in ECM.
*6: 1st trip DTC will be cleared after
vehicle is driven once (pattern B)
without the same malfunction.
*7: When the same malfunction is
detected in the 2nd trip, the 1st
trip freeze frame data will be
cleared.
SEF393S
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG16I18DE
OBD System Operation Chart (Cont'd)
EC-53
4) 1st trip freeze frame data
5) System readiness test (SRT) codes
6) Test values
7) Distance traveled while MI is activated.
8) Others
WORK SUPPORT MODENCEC0034S04
WORK ITEM CONDITION USAGE
FUEL PRESSURE RELEASEIFUEL PUMP WILL STOP BY TOUCHING ªSTARTº
DURING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS.When releasing fuel pressure
from fuel line
TARGET IDLE RPM ADJ*IIDLE CONDITION When setting target idle speed
TARGET IGNITION TIMING ADJ*IIDLE CONDITION When adjusting target ignition tim-
ing
After adjustment, confirm target
ignition timing with a timing light.
*: This function is not necessary in the usual service procedure.
SELF DIAGNOSTIC MODENCEC0034S05DTC and 1st Trip DTCNCEC0034S0501Regarding items of ªDTC and 1st trip DTCº, refer to
ªTROUBLE DIAGNOSIS Ð INDEXº, EC-QG-6.
Freeze Frame Data and 1st Trip Freeze Frame DataNCEC0034S0502
Freeze frame data
item*Description
DIAG TROUBLE
CODE
[PXXXX]IEngine Control component part/control system has a trouble code, it is displayed as ªPXXXXº. [Refer to
ªAlphabetical & P No. Index for DTCº (EC-QG-6).]
FUEL SYS DATAIªFuel injection system statusº at the moment a malfunction is detected is displayed.
IOne mode in the following is displayed.
ªMODE 2º: Open loop due to detected system malfunction
ªMODE 3º: Open loop due to driving conditions (power enrichment, deceleration enrichment)
ªMODE 4º: Closed loop - using oxygen sensor(s) as feedback for fuel control
ªMODE 5º: Open loop - has not yet satisfied condition to go to closed loop
CAL/LD VALUE [%]IThe calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP [ÉC]
or [ÉF]IThe engine coolant temperature at the moment a malfunction is detected is displayed.
S-FUEL TRIM [%]IªShort-term fuel trimº at the moment a malfunction is detected is displayed.
IThe short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel
schedule.
L-FUEL TRIM [%]IªLong-term fuel trimº at the moment a malfunction is detected is displayed.
IThe long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule
than short-term fuel trim.
ENGINE SPEED
[rpm]IThe engine speed at the moment a malfunction is detected is displayed.
VHCL SPEED [km/h]
or [mph]IThe vehicle speed at the moment a malfunction is detected is displayed.
*: The items are the same as those of 1st trip freeze frame data.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG16I18DE
CONSULT-II (Cont'd)
EC-58
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
AIR COND SIG
[ON/OFF]qqIIndicates [ON/OFF] condition of the air condi-
tioner switch as determined by the air condition-
ing signal.
P/N POSI SW
[ON/OFF]qqIIndicates [ON/OFF] condition from the PNP
switch signal.
PW/ST SIGNAL
[ON/OFF]qqIIndicates [ON/OFF] condition of the power steer-
ing oil pressure switch determined by the power
steering oil pressure switch signal.
LOAD SIGNAL
[ON/OFF]qqIIndicates [ON/OFF] condition from the electrical
load signal and/or lighting switch.
ON ... rear defogger is operating and/or lighting
switch is on.
OFF ... rear defogger is not operating and light-
ing switch is not on.
IGNITION SW
[ON/OFF]qIIndicates [ON/OFF] condition from ignition
switch.
HEATER FAN SW
[ON/OFF]qIIndicates [ON/OFF] condition from the heater
fan switch.
INJ PULSE-B1
[msec]qIIndicates the actual fuel injection pulse width
compensated by ECM according to the input
signals.IWhen the engine is stopped, a
certain computed value is indi-
cated.
B/FUEL SCHDL
[msec]IªBase fuel scheduleº indicates the fuel injection
pulse width programmed into ECM, prior to any
learned on board correction.
IGN TIMING [BTDC]qIIndicates the ignition timing computed by ECM
according to the input signals.
IACV-AAC/V [step]qIIndicates the IACV-AAC valve control value
computed by ECM according to the input sig-
nals.
A/F ALPHA-B1 [%]qIIndicates the mean value of the air-fuel ratio
feedback correction factor per cycle.IWhen the engine is stopped, a
certain value is indicated.
IThis data also includes the data
for the air-fuel ratio learning
control.
AIR COND RLY
[ON/OFF]qIIndicates the air conditioner relay control condi-
tion determined by ECM according to the input
signals.
FUEL PUMP RLY
[ON/OFF]qIIndicates the fuel pump relay control condition
determined by ECM according to the input sig-
nals.
INT/V SOL-B1
[ON/OFF]IThe control condition of the valve timing sole-
noid valve (determined by ECM according to the
input signal) is indicated.
ON ... Intake valve timing control operating
OFF ... Intake valve timing control not operating
COOLING FAN
[ON/OFF]qIIndicates the control condition of the cooling fan
determined by ECM according to the input sig-
nals.
HI ... High speed operation
LOW ... Low speed operation
OFF ... Stop
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG16I18DE
CONSULT-II (Cont'd)
EC-60
DATA MONITOR (SPEC) MODENLEC1365S07
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
MAS A/F SE-B1 [V]qqIThe signal voltage of the mass air flow sen-
sor specification is displayed.IWhen the engine is running, specifi-
cation range is indicated.
B/FUEL SCHDL
[msec]IªBase fuel scheduleº indicates the fuel injec-
tion pulse width programmed into ECM,
prior to any learned on board correction.IWhen the engine is running, specifi-
cation range is indicated.
A/F ALPHA-B1 [%]qIIndicates the mean value of the air-fuel ratio
feedback correction factor per cycle.IWhen the engine is running, specifi-
cation range is indicated.
IThis 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 MODENCEC0034S07
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJECTIONIEngine: Return to the original
trouble condition
IChange the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.IHarness and connector
IFuel injectors
IHeated oxygen sensor 1 (front)
IACV-AAC/V
OPENINGIEngine: After warming up, idle
the engine.
IChange the IACV-AAC valve
opening steps using CONSULT-
II.Engine speed changes according
to the opening steps.IHarness and connector
IIACV-AAC valve
ENG COOLANT
TEMPIEngine: Return to the original
trouble condition
IChange the engine coolant tem-
perature indication using CON-
SULT-II.If trouble symptom disappears, see
CHECK ITEM.IHarness and connector
IEngine coolant temperature sen-
sor
IFuel injectors
IGNITION TIMINGIEngine: Return to the original
trouble condition
ITiming light: Set
IRetard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.IªBase Idle Air Volume Initializingº
(Refer to EC-QG-33.)
ICamshaft position sensor
(PHASE)
ICrankshaft position sensor
(POS)
IEngine component parts and
installing conditions
POWER BAL-
ANCEIEngine: After warming up, idle
the engine.
IAir conditioner switch ªOFFº
IShift lever ªNº
ICut off each injector signal one
at a time using CONSULT-II.Engine runs rough or dies.IHarness and connector
ICompression
IInjectors
IPower transistor
ISpark plugs
IIgnition coils
COOLING FANIIgnition switch: ON
ITurn the cooling fan ªONº and
ªOFFº using CONSULT-II.Cooling fan moves and stops.IHarness and connector
ICooling fan motor
FUEL PUMP
RELAYIIgnition switch: ON
(Engine stopped)
ITurn the fuel pump relay ªONº
and ªOFFº using CONSULT-II
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.IHarness and connector
IFuel pump relay
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG16I18DE
CONSULT-II (Cont'd)
EC-62
Basic InspectionNCEC0038Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
IHeadlamp switch is OFF,
On vehicle equipped with daytime light system, set lighting
switch to the 1st position to light only small lamps.
IAir conditioner switch is OFF,
IRear window defogger switch is OFF,
ISteering wheel is in the straight-ahead position, etc.
1 INSPECTION START
1. Check service records for any recent repairs that may indicate a related problem, or a current need for scheduled
maintenance.
2. Open engine hood and check the following:
IHarness connectors for improper connections
IVacuum hoses for splits, kinks and improper connections
IWiring for improper connections, pinches and cuts
IAir cleaner clogging
IHoses and ducts for leaks
SEF983U
©GO TO 2.
2 CHECK THROTTLE DRUM OPERATION-I
Confirm that throttle drum is in contact with the stopper.
OK or NG
OK (with CONSULT-II)©GO TO 5.
OK (without CONSULT-
II)©GO TO 8.
NG©GO TO 3.
3 CHECK ACCELERATOR WIRE INSTALLATION
Check accelerator wire for slack
OK or NG
OK©GO TO 4.
NG©Adjust accelerator wire. Refer to FE section, ªAdjusting Accelerator Wireº.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG16I18DE
Basic Inspection
EC-72