2001 NISSAN ALMERA ECU

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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.
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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 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

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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-280.
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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

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Component InspectionNJEC0170HEATED OXYGEN SENSOR 2 (REAR)NJEC0170S01With 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
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 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 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.
DTC P0139 HEATED OXYGEN SENSOR 2 (REAR)
(RESPONSE MONITORING)
QG
Component Inspection
EC-282

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DTC Confirmation ProcedureNJEC0175NOTE:
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.
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.
3) Stop vehicle with engine running.
4) Let engine idle for 1 minute.
5) Maintain the following conditions for at least 5 consecutive
minutes.
ENG SPEED Above 1,500 rpm
Selector lever Suitable position
6) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-288.
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Overall Function CheckNJEC0176Use this procedure to check the overall function of the heated oxy-
gen sensor 2 (rear) 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 after 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 below 2V during this procedure.
5) If NG, go to ªDiagnostic Procedureº, EC-288.
DTC P0140 HEATED OXYGEN SENSOR 2 (REAR) (HIGH VOLTAGE)QG
DTC Confirmation Procedure
EC-285

4 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 5.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK HARNESS CONNECTOR
Check heated oxygen sensor 2 (rear) harness connector for water.
Water should not exist.
OK or NG
OK©GO TO 6.
NG©Repair or replace harness connector.
6 CHECK HEATED OXYGEN SENSOR 2 (REAR)
Refer to ªComponent Inspectionº, EC-289.
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 InspectionNJEC0179HEATED OXYGEN SENSOR 2 (REAR)NJEC0179S01With 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
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.
DTC P0140 HEATED OXYGEN SENSOR 2 (REAR) (HIGH VOLTAGE)QG
Diagnostic Procedure (Cont'd)
EC-289

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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 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 P0140 HEATED OXYGEN SENSOR 2 (REAR) (HIGH VOLTAGE)QG
Component Inspection (Cont'd)
EC-290

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.
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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

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On Board Diagnosis LogicNJEC0240The ECM monitors the switching frequency ratio of heated oxygen
sensors 1 (front) and 2 (rear).
A three way catalyst with high oxygen storage capacity will indicate
a low switching frequency of heated oxygen sensor 2 (rear). As
oxygen storage capacity decreases, the heated oxygen sensor 2
(rear) switching frequency will increase.
When the frequency ratio of heated oxygen sensors 1 (front) and
2 (rear) approaches a specified limit value, the three way catalyst
malfunction is diagnosed.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0420
0420+Three way catalyst does not operate properly.
+Three way catalyst does not have enough oxygen stor-
age capacity.+Three way catalyst
+Exhaust tube
+Intake air leaks
+Injectors
+Injector leaks
+Spark plug
+Improper ignition timing
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DTC Confirmation ProcedureNJEC0241CAUTION:
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.
With CONSULT-II
TESTING CONDITION:
+Open engine hood before conducting following proce-
dure.
+Do not hold engine speed more than specified minutes
below.
1) Turn ignition switch ªONº.
2) Select ªDTC & SRT CONFIRMATIONº then ªSRT WORK SUP-
PORTº mode with CONSULT-II.
3) Start engine.
4) Rev engine up to 3,000±500 rpm and hold it for 3 consecutive
minutes then release the accelerator pedal completely.
If ªCOMPLETEDº appears on the CONSULT-II screen, go to
step 7.
5) Wait 5 seconds at idle.
6) Rev engine up to 2,500±500 rpm and maintain it until ªINCMPº
of CATALYST changes to ªCMPLTº (it will take approximately
5 minutes.)
If not ªCMPLTº, stop engine and cool it down to less than 70ÉC
(158ÉF) and then retest from step 1.
7) Select ªSELF-DIAG RESULTSº mode with CONSULT-II.
8) Confirm that the 1st trip DTC is not detected.
If the 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-360.
DTC P0420 THREE WAY CATALYST FUNCTIONQG
On Board Diagnosis Logic
EC-359