Page 345 of 1306

2 CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªSELF-LEARNING CONTº in ªACTIVE TESTº mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching ªCLEARº.
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 OFF.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 3 seconds at idle speed.
SEF293W
4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure 1st trip DTC P0102 is displayed.
6. Erase the 1st trip DTC memory. Refer to ªHOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATIONº,
EC-3060.
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 detected? Is it difficult to start engine?
YesorNo
Ye s©Perform trouble diagnosis for DTC P0172. Refer to EC-3244.
No©GO TO 3.
3 CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 1 harness connector.
3. Check harness connector for water.
Water should not exit.
OK or NG
OK©GO TO 4.
NG©Repair or replace harness connector.
DTC P1144 HO2S1KA24DE (EURO OBD)
Diagnostic Procedure
EC-3320
Page 346 of 1306
4 CHECK HEATED OXYGEN SENSOR 1 HEATER
Check resistance between terminals 3 and 1. Refer to wiring diagram.
Resistance: 2.3 - 4.3Wat 25ÉC (77ÉF)
Check continuity between terminals 2 and 1, 3 and 2. Refer to wiring diagram.
Continuity should not exist.
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 system threads using Oxygen Sensor Thread Cleaner tool
J-43897-18 or J-43897-12 and approved anti-seize lubricant.
OK or NG
OK (With CONSULT-II)©GO TO 5.
OK (Without CONSULT-
II)©GO TO 6.
NG©Replace heated oxygen sensor 1.
DTC P1144 HO2S1KA24DE (EURO OBD)
Diagnostic Procedure
EC-3321
Page 347 of 1306

5 CHECK HEATED OXYGEN SENSOR 1
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Select ªMANU TRIGº in ªDATA MONITORº mode, and the trigger point is adjusted to 100%.
4. Select ªHO2S1 (B1)º and ªHO2S1 MNTR (B1)º in item selection.
5. Hold engine speed at 2,000 rpm under no load during the following steps.
6. Touch ªRECORDº on CONSULT-II screen.
SEF646Y
7. Check the following.
+ªHO2S1 MNTR (B1)º in ªDATA MONITORº mode changes from ªRICHº to ªLEANº to ªRICHº 5 times in 10 seconds.
5 times (cycles) are counted as shown below:
SEF217YA
+ªHO2S1 (B1)º voltage goes above 0.6V at least once.
+ªHO2S1 (B1)º voltage goes below 0.3V at least once.
+ªHO2S1 (B1)º voltage never exceeds 1.0V.
SEF648Y
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 system threads using Oxygen Sensor Thread Cleaner
tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
OK or NG
OK©GO TO 7.
NG©Replace heated oxygen sensor 1.
DTC P1144 HO2S1KA24DE (EURO OBD)
Diagnostic Procedure
EC-3322
Page 348 of 1306

6 CHECK HEATED OXYGEN SENSOR 1
Without CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Set voltmeter probes between ECM terminal 50 (Heated oxygen sensor 1 signal) and engine ground.
AEC873A
4. Check the following with engine speed held at 2,000 rpm constant under no load.
+The voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V more than five times within 10 seconds.
1 time: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V
2 times: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V®0.6 - 1.0V®0 - 0.3V
+The maximum voltage is over 0.6V at least one time.
+The minimum voltage is below 0.3V at least one time.
+The voltage never exceeds 1.0V.
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 system threads using Oxygen Sensor Thread Cleaner
tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
OK or NG
OK©GO TO 7.
NG©Replace heated oxygen sensor 1.
7 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3123.
Refer to ªWiring Diagramº, EC-3216, for circuit.
©INSPECTION END
DTC P1144 HO2S1KA24DE (EURO OBD)
Diagnostic Procedure
EC-3323
Page 349 of 1306

SEF327R
Component DescriptionNEEC0144The heated oxygen sensor 2, after three way catalyst, monitors the
oxygen level in the exhaust gas.
Even if switching characteristics of the heated oxygen sensor 1 are
shifted, the air fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
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 is not used
for engine control operation.
CONSULT-II Reference Value in Data Monitor
Mode
NEEC0145Specification 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 ValueNEEC0146Specification 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)
56 L/W Heated oxygen sensor 2[Engine is running]
+After warming up to normal operating tempera-
ture and revving engine from idle to 3,000 rpm
quickly0 - Approximately 1.0V
SEF304U
On Board Diagnosis LogicNEEC0147The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxy-
gen storage capacity before the three way catalyst causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the minimum voltage of the sen-
sor is sufficiently low during various driving conditions such as
fuel-cut.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P1146
1146+The minimum voltage from the sensor does not reach
the specified voltage.+Harness or connectors
(The sensor circuit is open or shorted.)
+Heated oxygen sensor 2
+Fuel pressure
+Injectors
DTC P1146 HO2S2KA24DE (EURO OBD)
Component Description
EC-3324
Page 350 of 1306

SEC314D
DTC Confirmation ProcedureNEEC0148
SEC315D
SEC316D
CAUTION:
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
5 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-IINEEC0148S01Procedure for COND1NEEC0148S01011. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº and wait at least 5 seconds.
3. Turn ignition switch ªONº and select ªHO2S2 (B1) P1146º 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 More than 1,000 rpm
B/FUEL SCHDL More than 1.0 msec
COOLANT TEMP/S 70 - 105ÉC
Selector level 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.
DTC P1146 HO2S2KA24DE (EURO OBD)
DTC Confirmation Procedure
EC-3325
Page 351 of 1306
![NISSAN PICK-UP 2001 Repair Manual PBIB0556E
Procedure for COND2NEEC0148S01021. While driving, release accelerator pedal completely from the
above condition [step 8] until ªINCOMPLETEº at ªCOND2º on
CONSULT-II screen has turned to NISSAN PICK-UP 2001 Repair Manual PBIB0556E
Procedure for COND2NEEC0148S01021. While driving, release accelerator pedal completely from the
above condition [step 8] until ªINCOMPLETEº at ªCOND2º on
CONSULT-II screen has turned to](/manual-img/5/57372/w960_57372-350.png)
PBIB0556E
Procedure for COND2NEEC0148S01021. While driving, release accelerator pedal completely from the
above condition [step 8] until ªINCOMPLETEº at ªCOND2º on
CONSULT-II screen has turned to ªCOMPLETEDº. (If 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.
SEC775C
Procedure for COND3NEEC0148S01031. Stop vehicle and let is 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 EC-3328, ªDiagnostic Procedureº.
AEC874A
Overall Function CheckNEEC0149Use this procedure to check the overall function of the heated oxy-
gen sensor 2 circuit. During this check, a 1st trip DTC might not be
confirmed.
CAUTION:
Always drive vehicle at a safe speed.
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 56 (Heated oxy-
gen sensor 2 signal) 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 below 0.54V 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.
The voltage should be below 0.54V at least once during
this procedure.
6) If NG, go to ªDiagnostic Procedureº, EC-3328.
DTC P1146 HO2S2KA24DE (EURO OBD)
DTC Confirmation Procedure
EC-3326
Page 352 of 1306
Wiring DiagramNEEC0150
GEC246A
DTC P1146 HO2S2KA24DE (EURO OBD)
Wiring Diagram
EC-3327