
Diagnostic ProcedureNJEC0160
1 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
JEF104Y
©GO TO 2.
2 CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªSELF-LEARN CONTROLº in ªWORK SUPPORTº mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching ªSTARTº.
SEF215Z
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 detected? Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure 1st trip DTC P0100 is displayed.
6. Erase the 1st trip DTC memory. Refer to ªHow to Erase Emission-related Diagnostic Informationº, EC-70.
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC 0171 detected? Is it difficult to start engine?
YesorNo
Ye s©Perform trouble diagnosis for DTC P0171. Refer to EC-297.
No©GO TO 3.
DTC P0138 HEATED OXYGEN SENSOR 2 (REAR) (MAX. VOLTAGE
MONITORING)
QG
Diagnostic Procedure
EC-272

SEF841Y
SEF842Y
SEF843Y
DTC Confirmation ProcedureNJEC0598CAUTION:
Always drive vehicle at a safe speed.
NOTE:
+ªCOMPLETEDº will appear on CONSULT-II screen when all
tests ªCOND1º, ªCOND2º and ªCOND3º are completed.
+If ªDTC Confirmation Procedure º has been previously
conducted, always turn ignition switch ªOFFº and wait at least
9 seconds before conducting the next test.
TESTING CONDITION:
Never stop engine during this procedure. If the engine is
stopped, retry this procedure from step 2 in ªProcedure for
COND1º.
With CONSULT-II
Procedure for COND1
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds.
3) Turn ignition switch ªONº and select ªHO2S2 (B1) P0139º of
ªHO2S2º in ªDTC WORK SUPPORTº mode with CONSULT-II.
4) Touch ªSTARTº.
5) Start engine and let it idle for at least 30 seconds.
6) Rev engine up to 2,000 rpm 2 or 3 times quickly under no load.
If ªCOMPLETEDº appears on CONSULT-II screen, go to step
2 in ªProcedure for COND3º.
If ªCOMPLETEDº does not appear on CONSULT-II screen, go
to the following step.
7) Drive vehicle at a speed of more than 70 km/h (43 MPH) for 2
consecutive minutes.
8) When the following conditions are met, ªTESTINGº will be dis-
played at ªCOND1º on the CONSULT-II screen. Maintain the
conditions continuously until ªTESTINGº changes to ªCOM-
PLETEDº. (It will take approximately 60 seconds.)
ENG SPEED 1,500 - 3,600 rpm
Vehicle speed Above 70 km/h (43 MPH)
Selector lever Suitable position
NOTE:
+If ªTESTINGº is not displayed after 5 minutes, retry from
step 2 in ªProcedure for COND1º.
+If ªCOMPLETEDº already appears at ªCOND2º on CON-
SULT-II screen before ªProcedure for COND2º is
conducted, it is unnecessary to conduct step 1 in ªProce-
dure for COND2º.
SEF844Y
Procedure for COND2
1) While driving, release accelerator pedal completely with ªODº
OFF (A/T models), or 4th gear position (M/T models) from the
above condition [step 8] until ªINCOMPLETEº at ªCOND2º on
CONSULT-II screen has turned to ªCOMPLETEDº. (It will take
approximately 4 seconds.)
NOTE:
If ªCOMPLETEDº already appears at ªCOND3º on CONSULT-II
screen before ªProcedure for COND3º is conducted, it is
unnecessary to conduct step 1 in ªProcedure for COND3º.
DTC P0139 HEATED OXYGEN SENSOR 2 (REAR)
(RESPONSE MONITORING)
QG
On Board Diagnosis Logic (Cont'd)
EC-276

SEF668Y
Procedure for COND3
1) Stop vehicle and let it idle until ªINCOMPLETEº of ªCOND3º on
CONSULT-II screen has turned to ªCOMPLETEDº. (It will take
a maximum of approximately 6 minutes.)
2) Make sure that ªOKº is displayed after touching ªSELF-DIAG
RESULTSº.
If ªNGº is displayed, refer to ªDiagnostic Procedureº, EC-280.
SEF032X
Overall Function CheckNJEC0599Use this procedure to check the overall function of the rear heated
oxygen sensor circuit. During this check, a 1st trip DTC might not
be confirmed.
Without CONSULT-II
1) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes.
2) Stop vehicle with engine running.
3) Set voltmeter probes between ECM terminals 63 (HO2S2 sig-
nal) and engine ground.
4) Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should change at more than 0.06V for 1 sec-
ond during this procedure.
If the voltage can be confirmed in step 4, step 5 is not
necessary.
5) Keep vehicle at idling for 10 minutes, then check the voltage.
Or check the voltage when coasting from 80 km/h (50 MPH)
in 3rd gear position (M/T), D position with ªODº OFF (A/T).
The voltage should change at more than 0.06V for 1 sec-
ond during this procedure.
6) If NG, go to ªDiagnostic Procedureº, EC-280.
DTC P0139 HEATED OXYGEN SENSOR 2 (REAR)
(RESPONSE MONITORING)
QG
DTC Confirmation Procedure (Cont'd)
EC-277

Diagnostic ProcedureNJEC0169
1 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
JEF104Y
©GO TO 2.
2 CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªSELF-LEARN CONTROLº in ªWORK SUPPORTº mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching ªSTARTº.
SEF215Z
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 detected? Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure 1st trip DTC P0100 is displayed.
6. Erase the 1st trip DTC memory. Refer to ªHow to Erase Emission-related Diagnostic Informationº, EC-70.
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC 0172 detected? Is it difficult to start engine?
YesorNo
Ye s©Perform trouble diagnosis for DTC P0172. Refer to EC-305.
No©GO TO 3.
DTC P0139 HEATED OXYGEN SENSOR 2 (REAR)
(RESPONSE MONITORING)
QG
Diagnostic Procedure
EC-280

On Board Diagnosis LogicNJEC0183
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0141
0141+The current amperage in the heated oxygen sensor 2
heater (rear) circuit is out of the normal range.
[An improper voltage drop signal is sent to ECM through
the heated oxygen sensor 2 heater (rear).]+Harness or connectors
(The heated oxygen sensor 2 heater (rear) cir-
cuit is open or shorted.)
+Heated oxygen sensor 2 heater (rear)
DTC Confirmation ProcedureNJEC0184NOTE:
If ªDTC Confirmation Procedure º has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is in between 10.5V and 16V at idle.
SEF175Y
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
with CONSULT-II.
2) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes. Engine speed must be
maintained at speeds of 3,600 rpm or less during vehicle
operations.
3) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-295.
With GST
1) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes. Engine speed must be
maintained at speeds of 3,600 rpm or less during vehicle
operations.
2) Turn ignition switch ªOFFº and wait at least 9 seconds.
3) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes.
4) Select ªMODE 3º with GST.
5) If DTC is detected, go to ªDiagnostic Procedureº, EC-295.
When using GST, ªDTC Confirmation Procedure º should be
performed twice as much as when using CONSULT-II because
GST cannot display MODE 7 (1st trip DTC) concerning this
diagnosis. Therefore, using CONSULT-II is recommended.
DTC P0141 HEATED OXYGEN SENSOR 2 HEATER (REAR)QG
On Board Diagnosis Logic
EC-292

DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0400
0400+No EGR flow is detected under conditions that call for
EGR.+Harness or connectors
(EGR volume control valve circuit is open or
shorted.)
+EGR volume control valve stuck closed
+Dead (Weak) battery
+EGR passage clogged
+EGR temperature sensor and circuit
+Exhaust gas leaks
SEF013Y
SEF845Y
SEF846Y
SEF235Y
DTC Confirmation ProcedureNJEC0229CAUTION:
Always drive vehicle at a safe speed.
NOTE:
+If ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
9 seconds before conducting the next test.
+P0400 will not be displayed at ªSELF-DIAG RESULTSº mode
with CONSULT-II even though DTC work support test result is
ªNGº.
TESTING CONDITION:
+Before performing the following procedure, confirm bat-
tery voltage is more than 10V at idle, then stop engine
immediately.
+For best result, perform the test at a temperature of 0ÉC
(32ÉF) or higher.
With CONSULT-II
1) Turn ignition switch ªOFFº and wait at least 9 seconds.
2) Turn ignition switch ªONº.
3) Check ªCOOLAN TEMP/Sº in ªDATA MONITORº mode with
CONSULT-II and confirm it is within the range listed below.
COOLAN TEMP/S: Less than 40ÉC (104ÉF)
If the value is out of range, park the vehicle in a cool place and
allow the engine temperature to stabilize. Do not attempt to
lower the engine coolant temperature with a fan or means
other than ambient air. Doing so may produce an inaccurate
diagnostic result.
4) Start engine and let it idle monitoring ªCOOLAN TEMP/Sº
value. When the ªCOOLAN TEMP/Sº value reaches 70ÉC
(158ÉF), immediately go to the next step.
5) Select ªEGR SYSTEM P0400º of ªEGR SYSTEMº in ªDTC
WORK SUPPORTº mode with CONSULT-II.
6) Touch ªSTARTº.
7) Accelerate vehicle to a speed of 40 km/h (25 MPH) once and
then stop vehicle with engine running.
If ªCOMPLETEDº appears on CONSULT-II screen, go to step
9.
If ªCOMPLETEDº does not appear on CONSULT-II screen, go
to the following step.
8) When the following conditions are met, ªTESTINGº will be dis-
played on the CONSULT-II screen. Maintain the conditions
until ªTESTINGº changes to ªCOMPLETEDº. (It will take
approximately 45 seconds or more.)
DTC P0400 EGR FUNCTION (CLOSED) (WHERE FITTED)QG
On Board Diagnosis Logic (Cont'd)
EC-345

ENG SPEED Above 2,400 rpm
Vehicle speed Above 90 km/h (56 MPH)
B/FUEL SCHDL 4.0 - 8.0 msec
Selector lever 4th or 5th
If ªTESTINGº is not displayed after 5 minutes, retry from
step 2.
9) Make sure that ªOKº is displayed after touching ªSELF-DIAG
RESULTSº. If ªNGº is displayed, refer to ªDiagnostic
Procedureº, EC-349.
With GST
1) Turn ignition switch ªONº.
2) Check engine coolant temperature in MODE 1 with GST.
Engine coolant temperature: Less than 40ÉC (104ÉF)
If the value is out of range, park the vehicle in a cool place and
allow the engine temperature to stabilize. Do not attempt to
lower the engine coolant temperature with a fan or means
other than ambient air. Doing so may produce an inaccurate
diagnostic result.
3) Start engine and let it idle monitoring the value of ªCOOLAN
TEMP/Sº. When the engine coolant temperature reaches 70ÉC
(158ÉF), immediately go to the next step.
4) Maintain the following conditions for at least 1 minute.
Engine speed Above 2,400 rpm
Vehicle speed Above 90 km/h (56 MPH)
Selector lever 4th or 5th
5) Stop vehicle.
6) Turn ignition switch ªOFFº and wait at least 9 seconds, then
turn ªONº.
7) Repeat step 2 to 4.
8) Select ªMODE 3º with GST.
9) If DTC is detected, go to ªDIAGNOSTIC PROCEDUREº,
EC-349.
+When using GST, ªDTC CONFIRMATION PROCEDUREº
should be performed twice as much as when using CON-
SULT-II because GST cannot diaplay MODE 7 (1st trip
DTC) concerning this diagnosis. Therefore, using CON-
SULT-II is recommended.
DTC P0400 EGR FUNCTION (CLOSED) (WHERE FITTED)QG
DTC Confirmation Procedure (Cont'd)
EC-346

Diagnostic Procedure=NJEC0298
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.
See EC-391.
5. Is the 1st trip DTC P0605 displayed again?
With GST
1. Turn ignition switch ªONº.
2. Select MODE 4 with GST.
3. Touch ªERASEº.
4. Perform ªDTC Confirmation Procedureº.
See EC-391.
5. Is the 1st trip DTC P0605 displayed again?
YesorNo
Ye s©GO TO 2.
No©INSPECTION END
2 REPLACE ECM
1. Replace ECM.
2. Perform initialization of NATS (NISSAN ANTI-THEFT SYSTEM) system and registration of all NATS ignition key IDs.
Refer to ªNATS (NISSAN ANTI-THEFT SYSTEM)º, EC-74.
3. Perform ªIdle Air Volume Learningº, EC-57,
Is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©INSPECTION END
INCMP©Follow the construction of ªIdle Air Volume Learningº.
DTC P0605 ECMQG
Diagnostic Procedure
EC-392