+Erasing the emission-related diagnostic information using CONSULT-II is easier and quicker than
switching the diagnostic test mode using the data link connector.
NATS (Nissan Anti-Theft System)
+If the security indicator lights up with the ignition switch
in the ªONº position or ªNATS MALFUNCTIONº is dis-
played on ªSELF-DIAG RESULTSº screen, perform self-
diagnostic results mode with CONSULT-II using NATS
program card. Refer to ªNATS (Nissan Anti-Theft Sys-
tem)º in EL section.
+Confirm no self-diagnostic results of NATS is displayed
before touching ªERASEº in ªSELF-DIAG RESULTSº
mode with CONSULT-II.
+When 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 initialization
and NATS ignition key ID registration, refer to CON-
SULT-II operation manual, NATS.
Malfunction Indicator Lamp (MIL)
DESCRIPTION
The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON
without the engine running. This is a bulb check.
+If the MIL does not light up, refer to EL section (ªWARNING
LAMPS AND CHIMEº) or see EC-3647.
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.
Fuel filter switch is equipped except for Europe.
If MIL illuminates or blinks irregularly after starting engine,
water may have accumulated in fuel filter. Drain water from
fuel filter. Refer to EC-3426.
On board diagnostic system function
The on board diagnostic system has the following three func-
tions.
SEF252Z
SAT652J
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD25DDTi
Diagnostic Trouble Code (DTC) (Cont'd)
EC-3429
Relationship between MIL, DTC, CONSULT-II and driving patterns
*1: When a malfunction is detected,
MIL will light up.
*2: When the same malfunction is
detected in two consecutive driving
patterns, MIL will stay lit up.
*3: When a malfunction is detected for
the first time, the DTC will be
stored in ECM.*4: The DTC will not be displayed any
longer after vehicle is driven 40
times without the same malfunc-
tion. (The DTC still remain in
ECM.)*5: Other screens except SELF-DIAG-
NOSTIC RESULTS & DATA MONI-
TOR (AUTO TRIG) cannot display
the malfunction. DATA MONITOR
(AUTO TRIG) can display the mal-
function at the moment it is
detected.
SEC946C
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD25DDTi
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-3433
ENGINE CONTROL COMPONENT PARTS/CONTROL
SYSTEMS APPLICATION
ItemDIAGNOSTIC TEST MODE
SELF-DIAG
RESULTSDATA MONI-
TORACTIVE
TEST
ENGINE CONTROL COMPONENT PARTS
INPUTEngine coolant temperature sensor X X
Intake air temperature sensor X X
Vehicle speed sensor X X
Accelerator position sensor X X X
Accelerator position switch X X
Crankshaft position sensor (TDC) X X
Ignition switch (start signal) X
Park/Neutral position (PNP) switch X
Battery voltage X
Air conditioner switch X
Brake pedal position switch X X
Charge air pressure sensor X X
Heat up switch X
Stop lamp switch X X
OUTPUTGlow relayXX
EGR volume control valve X X X
Cooling fan relay X X X
Air conditioner relay X
X: Applicable
SELF-DIAGNOSTIC MODE
Regarding items detected in ªSELF-DIAG RESULTSº mode,
refer to ªTROUBLE DIAGNOSIS Ð INDEXº, EC-3400.
DATA MONITOR MODE
Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
CKPSzRPM (TDC)
[rpm]jj+The engine speed computed from the
crankshaft position sensor (TDC) signal
is displayed.
CMPSzRPMzPUMP
[rpm]jj+The engine speed computed from the
pulse signal sent from electronic control
fuel injection pump is displayed.
COOLAN TEMP/S
[ÉC] or [ÉF]
jj+The engine coolant temperature (deter-
mined by the signal voltage of the
engine coolant temperature sensor) is
displayed.+When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine cool-
ant temperature determined by the ECM
is displayed.
VHCL SPEED SE
[km/h] or [mph]jj+The vehicle speed computed from the
vehicle speed sensor signal is displayed.
FUEL TEMP SEN
[ÉC] or [ÉF]jj+The fuel temperature (sent from elec-
tronic control fuel injection pump) is dis-
played.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD25DDTi
CONSULT-II (Cont'd)
EC-3435
Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
ACCEL POS SEN [V]
jj+The accelerator position sensor signal
voltage is displayed.
FULL ACCEL SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the
accelerator position switch signal.
OFF ACCEL SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the
accelerator position switch signal.
SPILL/V [ÉCA]
j+The control position of spill valve (sent
from electronic control fuel injection
pump) is displayed.
BATTERY VOLT [V]
jj+The power supply voltage of ECM is dis-
played.
I/C INT/A T/S [V]
jj+The signal voltage of the intake air tem-
perature sensor is displayed.
P/N POSI SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the
park/neutral position switch signal.
START SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the
starter signal.+After starting the engine, [OFF] is dis-
played regardless of the starter signal.
AIR COND SIG
[ON/OFF]jj+Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
BRAKE SW [ON/OFF]
jj+Indicates [ON/OFF] condition from the
stop lamp switch signal.
BRAKE SW2
[ON/OFF]jj+Indicates [ON/OFF] condition from the
brake pedal position switch.
IGN SW
[ON/OFF]jj+Indicates [ON/OFF] condition from igni-
tion switch signal.
WARM UP SW
[ON/OFF]j+Indicates [ON/OFF] condition from the
heat up switch signal.
TURBO BST SEN
[kPa]j+The charge air pressure (determined by
the signal voltage sent to the ECM) is
displayed.
DECELER F/CUT
[ON/OFF]j+The [ON/OFF] condition from decelera-
tion fuel cut signal (sent from ECM) is
displayed.
INJ TIMG C/V [%]
j+The duty ratio of fuel injection timing
control valve (sent from electronic con-
trol fuel injection pump) is displayed.
AIR COND RLY
[ON/OFF]j+Indicates the control condition of the air
conditioner relay (determined by ECM
according to the input signals).
GLOW RLY [ON/OFF]
j+The glow relay control condition (deter-
mined by ECM according to the input
signal) is displayed.
COOLING FAN
[ON/OFF]
j+Indicates the control condition of the
cooling fans (determined by ECM
according to the input signal).
+ON ... Operates.
OFF ... Stopped.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD25DDTi
CONSULT-II (Cont'd)
EC-3436
Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
EGR VOL CON/V
[step]
j+Indicates the EGR volume control value
computed by the ECM according to the
input signals.
+The opening becomes larger as the
value increases.
BARO SEN [kPa]
j+The barometric pressure (determined by
the signal voltage from the barometric
pressure sensor built into the ECM) is
displayed.
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
COOLING FAN+Ignition switch: ON
+Turn cooling fan ªONº and ªOFFº
using CONSULT-II.Cooling fan moves and stops.+Harness and connector
+Cooling fan motor
+Cooling fan relay
OFF ACCEL PO
SIG+Clears the self-learning fully closed accelerator position, detected by accelerator position sensor, from the
ECM.
GLOW RLY+Ignition switch: ON (Engine
stopped)
+Turn the glow relay ªONº and
ªOFFº using CONSULT-II and
listen to operating sound.Glow relay makes the operating
sound.+Harness and connector
+Glow relay
INJ TIMING*1+Engine: Return to the original
trouble condition
+Retard the injection timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.+Electronic control fuel injection
pump
EGR VOL CONT/V+Ignition switch: ON
+Change EGR volume control
valve opening step using CON-
SULT-II.EGR volume control valve makes
an operating sound.+Harness and connector
+EGR volume control valve
*1: When using this item, DTC 0707 ªP7zF/INJ TIMG FBº may be detected. If so, erase it because it is not a malfunction.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD25DDTi
CONSULT-II (Cont'd)
EC-3437
REAL TIME DIAGNOSIS IN DATA MONITOR MODE
CONSULT-II has two kinds of triggers and they can be selected
by touching ªSETTINGº in ªDATA MONITORº mode.
1) ªAUTO TRIGº (Automatic trigger):
+The malfunction will be identified on the CONSULT-II screen
in real time.
In other words, DTC will be displayed if the malfunction is
detected by ECM.
At the moment a malfunction is detected by ECM, ªMONI-
TORº in ªDATA MONITORº screen is changed to ªRecording
Data ... xx%º as shown at left, and the data after the mal-
function detection is recorded. Then when the percentage
reached 100%, ªREAL-TIME DIAGº screen is displayed. If
ªSTOPº is touched on the screen during ªRecording Data ...
xx%º, ªREAL-TIME DIAGº screen is also displayed.
The recording time after the malfunction detection and the
recording speed can be changed by ªTRIGGER POINTº and
ªRecording Speedº. Refer to CONSULT-II OPERATION
MANUAL.
2) ªMANU TRIGº (Manual trigger):
+DTC will not be displayed automatically on CONSULT-II
screen even though a malfunction is detected by ECM.
DATA MONITOR can be performed continuously even
though a malfunction is detected.
Use these triggers as follows:
1) ªAUTO TRIGº
+While trying to detect the DTC by performing the ªDTC Con-
firmation Procedureº, be sure to select to ªDATA MONITOR
(AUTO TRIG)º mode. You can confirm the malfunction at the
moment it is detected.
+While narrowing down the possible causes, CONSULT-II
should be set in ªDATA MONITOR (AUTO TRIG)º mode,
especially in case the incident is intermittent.
When you are inspecting the circuit by gently shaking (or
twisting) the suspicious connectors, components and har-
ness in the ªDTC Confirmation Procedureº, the moment a
malfunction is found the DTC will be displayed. (Refer to GI
section, ªIncident Simulation Testsº in ªHOW TO PERFORM
EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCI-
DENTº.)
2) ªMANU TRIGº
+If the malfunction is displayed as soon as ªDATA MONITORº
is selected, reset CONSULT-II to ªMANU TRIGº. By select-
ing ªMANU TRIGº you can monitor and store the data. The
data can be utilized for further diagnosis, such as a compari-
son with the value for the normal operating condition.
SEF373Y
SEF707X
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD25DDTi
CONSULT-II (Cont'd)
EC-3438
DESCRIPTION FOR WORK FLOW
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using
the ªDIAGNOSTIC WORKSHEETº, EC-3440.
STEP IIBefore confirming the concern, check and write down (print out using CONSULT-II) the DTC, then erase the
DTC. Refer to EC-3428.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3470.
Study the relationship between the cause, specified by DTC, and the symptom described by the customer. (The
ªSymptom Matrix Chartº will be useful. Refer to EC-3451.) Also check related service bulletins for information.
STEP IIITry to confirm the symptom and under what conditions the incident occurs.
The ªDIAGNOSTIC WORK SHEETº is useful to verify the incident. Connect CONSULT-II to the vehicle in DATA
MONITOR (AUTO TRIG) mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3470.
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the DTC by driving in (or performing) the ªDTC Confirmation Procedureº. Check and read the DTC
by using CONSULT-II.
During the DTC verification, be sure to connect CONSULT-II to the vehicle in DATA MONITOR (AUTO TRIG)
mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3470.
In case the ªDTC Confirmation Procedureº is not available, perform the ªOverall Function Checkº instead. The
DTC cannot be displayed by this check, however, this simplified ªcheckº is an effective alternative.
The ªNGº result of the ªOverall Function Checkº is the same as the DTC detection.
STEP VTake the appropriate action based on the results of STEP I through IV.
If the malfunction code is indicated, proceed to TROUBLE DIAGNOSIS FOR DTC XXXX.
If the normal code is indicated, proceed to the Basic Inspection, EC-3445. Then perform inspections according to
the Symptom Matrix Chart. Refer to EC-3451.
STEP VIIdentify where to begin diagnosis based on the relationship study between symptom and possible causes.
Inspect the system for mechanical binding, loose connectors or wiring damage using (tracing) ªHarness Layoutsº.
Gently shake the related connectors, components or wiring harness with CONSULT-II set in ªDATA MONITOR
(AUTO TRIG)º mode.
Check the voltage of the related ECM terminals or monitor the output data from the related sensors with CON-
SULT-II. Refer to EC-3464 or EC-3461.
The ªDiagnostic Procedureº in EC section contains a description based on open circuit inspection. A short circuit
inspection is also required for the circuit check in the Diagnostic Procedure. For details, refer to GI section (ªCir-
cuit Inspectionº, ªHOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENTº).
Repair or replace the malfunction parts.
If the malfunctioning part cannot be detected, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENTº, EC-3470.
STEP VIIOnce you have repaired the circuit or replaced a component, you need to run the engine in the same conditions
and circumstances which resulted in the customer's initial complaint.
Perform the ªDTC Confirmation Procedureº and confirm the normal code (DTC No. 0505) is detected. If the inci-
dent is still detected in the final check, perform STEP VI by using a different method from the previous one.
Before returning the vehicle to the customer, be sure to erase the unnecessary (already fixed) DTC in ECM.
(Refer to EC-3428.)
TROUBLE DIAGNOSIS Ð INTRODUCTIONYD25DDTi
Work Flow (Cont'd)
EC-3443
Diagnostic Procedure
1 INSPECTION START
With CONSULT-II
1. Turn ignition switch ªONº.
2. Select ªSELF DIAG RESULTSº mode with CONSULT-II.
3. Touch ªERASEº.
4. Perform ªDTC Confirmation Procedureº, EC-3501, again.
5. Is the malfunction displayed again?
Without CONSULT-II
1. Turn ignition switch ªONº.
2. Erase the Diagnostic Test Mode II (Self-diagnostic results) memory.
3. Perform ªDTC Confirmation Procedureº, EC-3501, again.
4. Perform ªDiagnostic Test Mode II (Self-diagnostic results)º.
5. Is the DTC 0301 or 0901 displayed again?
Yes or No
YescGO TO 2.
NocINSPECTION END
2 REPLACE ECM
1. Replace ECM.
2. Perform initialization of NATS system and resistration of all NATS ignition key IDs. Refer to EC-3429. (Models with NATS)
3. Perform ªAccelerator Position Sensor Idle Position Learningº of ªBASIC SERVICE PROCEDUREº. Refer to EC-3427.
cINSPECTION END
DTC 0301 ECM 2, DTC 901 ECM 12YD25DDTi
EC-3502