2001 NISSAN ALMERA o2 sensor

SEF837Y
SEF838Y
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DTC Confirmation ProcedureNJEC0596CAUTION:
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 Procedureº 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) P0138º 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.
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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 is 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 P0138 HEATED OXYGEN SENSOR 2 (REAR) (MAX. VOLTAGE
MONITORING)
QG
On Board Diagnosis Logic (Cont'd)
EC-268

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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-272.
SEF032X
Overall Function CheckNJEC0597Use 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 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 engine up to 4,000 rpm under
no load at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.68V at least once 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 be above 0.68V at least once during
this procedure.
6) If NG, go to ªDiagnostic Procedureº, EC-272.
DTC P0138 HEATED OXYGEN SENSOR 2 (REAR) (MAX. VOLTAGE
MONITORING)
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DTC Confirmation Procedure (Cont'd)
EC-269

Wiring DiagramNJEC0159SEDAN MODELS AND HATCHBACK MODELS WITH
ECM IN ENGINE COMPARTMENT
NJEC0159S03
HEC787
DTC P0138 HEATED OXYGEN SENSOR 2 (REAR) (MAX. VOLTAGE
MONITORING)
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Wiring Diagram
EC-270

HATCHBACK MODELS WITH ECM IN CABINNJEC0159S04
HEC940
DTC P0138 HEATED OXYGEN SENSOR 2 (REAR) (MAX. VOLTAGE
MONITORING)
QG
Wiring Diagram (Cont'd)
EC-271

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.
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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)
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Diagnostic Procedure
EC-272

3 CHECK INPUT SIGNAL CIRCUIT
1. Disconnect heated oxygen sensor 2 (rear) harness connector and ECM harness connector.
2. Check harness continuity between ECM terminal 63 and heated oxygen sensor 2 (rear) harness connector terminal 1.
Refer to wiring diagram.
Continuity should exist.
3. Check harness continuity between ECM terminal 63 [or heated oxygen sensor 2 (rear) harness connector terminal 1]
and ground.
Continuity should not exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check the harness for open or short between ECM and heated oxygen sensor 2 (rear).
©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK GROUND CIRCUIT
1. Check harness continuity between heated oxygen sensor 2 (rear) harness connector terminal 4 and engine ground.
Refer to wiring diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 6.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK HEATED OXYGEN SENSOR 2 (REAR)
Refer to ªComponent Inspectionº, EC-273.
OK or NG
OK©GO TO 7.
NG©Replace heated oxygen sensor 2 (rear).
7 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
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Component InspectionNJEC0161HEATED OXYGEN SENSOR 2 (REAR)NJEC0161S01With 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) Select ªFUEL INJECTIONº in ªACTIVE TESTº mode, and
select ªHO2S2 (B1)º as the monitor item with CONSULT-II.
4) Check ªHO2S2 (B1)º at idle speed when adjusting ªFUEL
INJECTIONº to±25%.
ªHO2S2 (B1)º should be above 0.68V at least once when
DTC P0138 HEATED OXYGEN SENSOR 2 (REAR) (MAX. VOLTAGE
MONITORING)
QG
Diagnostic Procedure (Cont'd)
EC-273

the ªFUEL INJECTIONº is +25%.
ªHO2S2 (B1)º should be below 0.56V at least once when
the ªFUEL INJECTIONº is þ25%.
CAUTION:
+Discard any heated oxygen sensor which has been
dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
+Before installing new oxygen sensor, clean exhaust sys-
tem threads using Oxygen Sensor Thread Cleaner tool
and approved anti-seize lubricant.
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Without CONSULT-II
1) Start engine and drive vehicle at a speed of 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 be above 0.68V at least once.
If the voltage is above 0.68V at step 4, step 5 is not nec-
essary.
5) Check the voltage when revving up to 6,000 rpm under no
load. Or 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 be below 0.56V at least once.
CAUTION:
+Discard any heated oxygen sensor which has been
dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
+Before installing new oxygen sensor, clean exhaust sys-
tem threads using Oxygen Sensor Thread Cleaner tool
and approved anti-seize lubricant.
DTC P0138 HEATED OXYGEN SENSOR 2 (REAR) (MAX. VOLTAGE
MONITORING)
QG
Component Inspection (Cont'd)
EC-274

SEF327R
Component DescriptionNJEC0162The heated oxygen sensor 2 (rear), after three way catalyst, moni-
tors the oxygen level in the exhaust gas.
Even if switching characteristics of the heated oxygen sensor 1
(front) are shifted, the air fuel ratio is controlled to stoichiometric,
by the signal from the heated oxygen sensor 2 (rear).
This sensor is made of ceramic zirconia. The zirconia generates
voltage from approximately 1V in richer conditions to 0V in leaner
conditions.
Under normal conditions the heated oxygen sensor 2 (rear) is not
used for engine control operation.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0163Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
+Engine: After warming upRevving engine from idle to 3,000
rpm0 - 0.3V¨Approx. 0.6 - 1.0V
HO2S2 MNTR
(B1)LEAN¨RICH
ECM Terminals and Reference ValueNJEC0164Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
63 LHeated oxygen sensor 2
(rear)[Engine is running]
+After warming up to normal operating tempera-
ture and revving engine from idle to 2,000 rpm0 - Approximately 1.0V
SEF302U
On Board Diagnosis LogicNJEC0165The heated oxygen sensor 2 (rear) has a much longer switching
time between rich and lean than the heated oxygen sensor 1
(front). The oxygen storage capacity before the three way catalyst
causes the longer switching time. To judge the malfunctions of
heated oxygen sensor 2 (rear), ECM monitors whether the switch-
ing response of the sensor's voltage is faster than specified during
various driving conditions such as fuel-cut.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0139
0139+It takes more than the specified time for the sensor to
respond between rich and lean.+Harness or connectors
(The sensor circuit is open or shorted.)
+Heated oxygen sensor 2 (rear)
+Fuel pressure
+Injectors
+Intake air leaks
DTC P0139 HEATED OXYGEN SENSOR 2 (REAR)
(RESPONSE MONITORING)
QG
Component Description
EC-275