NISSAN X-TRAIL 2001 Service Repair Manual

DTC P1144 HO2S1
EC-301
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DTC P1144 HO2S1PFP:22690
Component DescriptionEBS00M86
The heated oxygen sensor 1 is placed into the exhaust manifold. It
detects the amount of oxygen in the exhaust gas compared to the
outside air. The heated oxygen sensor 1 has a closed-end tube
made of ceramic zirconia. The zirconia generates voltage from
approximately 1V in richer conditions to 0V in leaner conditions. The
heated oxygen sensor 1 signal is sent to the ECM. The ECM adjusts
the injection pulse duration to achieve the ideal air-fuel ratio. The
ideal air-fuel ratio occurs near the radical change from 1V to 0V.
CONSULT-II Reference Value in Data Monitor ModeEBS00M87
Specification data are reference values.
ECM Terminals and Reference ValueEBS00M88
Specification 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.
SEF463R
SEF288D
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 (B1)
●Engine: After warming upMaintaining engine speed at 2,000
rpm0 - 0.3V ←→ Approx. 0.6 - 1.0V
HO2S1 MNTR (B1)
●Engine: After warming upMaintaining engine speed at 2,000
rpmLEAN←→ RICH
Changes more than 5 times dur-
ing 10 seconds.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
92 G/WHeated oxygen sen-
sor 1[Engine is running]
●Warm-up condition
●Engine speed is 2,000 rpm.0 - Approximately 1.0V (Periodi-
cally change)

EC-302
[QR25(WITH EURO-OBD)]
DTC P1144 HO2S1
On Board Diagnosis Logic
EBS00M89
To judge the malfunction, the output from the heated oxygen sensor
1 is monitored to determine whether the “rich” output is sufficiently
high. The “lean” output is sufficiently low. When both the outputs are
shifting to the rich side, the malfunction will be detected.
DTC Confirmation ProcedureEBS00M8A
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
●Always perform at a temperature above −10°C (14°F).
●Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine and wait at least 5 seconds.
3. Turn ignition switch “ON” and select “HO2S1 (B1) P1144” of “HO2S1” in “DTC WORK SUPPORT” mode
with CONSULT-II.
4. Touch “START”.
5. Start engine and let it idle for at least 3 minutes.
NOTE:
Never raise engine speed above 3,600 rpm after this step. If
the engine speed limit is exceeded, return to step 5.
SEF299U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1144
11 4 4Heated oxygen sensor
1 rich shift monitoringThe maximum and minimum voltages from the
sensor are beyond the specified voltages.
●Heated oxygen sensor 1
●Heated oxygen sensor 1 heater
●Fuel pressure
●Injectors
PBIB0548E

DTC P1144 HO2S1
EC-303
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6. When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II screen. Maintain the conditions con-
tinuously until “TESTING” changes to “COMPLETED”. (It will
take approximately 50 seconds or more.)
If “TESTING” is not displayed after 5 minutes, retry from
step 2.
7. Make sure that “OK” is displayed after touching “SELF-DIAG
RESULTS”. If “NG” is displayed, refer to EC-303, "
Diagnostic
Procedure" .
Overall Function CheckEBS00M8B
Use this procedure to check the overall function of the heated oxygen sensor 1 circuit. During this check, a
DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes between ECM terminal 92 (HO2S1signal) and engine ground.
3. Check one of the following with engine speed held at 2,000 rpm
constant under no load.
–The maximum voltage is below 0.8V at least one time.
–The minimum voltage is below 0.35V at least one time.
4. If NG, go to EC-303, "
Diagnostic Procedure" .
Diagnostic ProcedureEBS00M8C
1.RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 2.
ENG SPEED 1,400 - 3,200 rpm
Vehicle speed Less than 100 km/h (62 MPH)
B/FUEL SCHDL 2.9 - 14.5 msec
Selector lever Suitable position
PBIB0549E
SEC772C
PBIB0543E
PBIB0494E

EC-304
[QR25(WITH EURO-OBD)]
DTC P1144 HO2S1
2. RETIGHTEN HEATED OXYGEN SENSOR 1
Loosen and retighten heated oxygen sensor 1.
>> GO TO 3.
3. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
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 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-56, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0172. Refer to EC-206 .
No >> GO TO 4.Tightening torque: 40 - 50 N·m (4.1 - 5.1 kg-m, 30 - 37 ft-lb)
PBIB0499E
SEF215Z
PBIB0495E

DTC P1144 HO2S1
EC-305
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4.CHECK HO2S1 CONNECTOR FOR WATER
1. Turn ignition switch “OFF”.
2. Disconnect heated oxygen sensor 1 harness connector.
3. Check connectors for water.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 1 HEATER
Refer to EC-132, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace heated oxygen sensor 1.
6.CHECK HEATED OXYGEN SENSOR 1
Refer to EC-305, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace heated oxygen sensor 1.
7.CHECK INTERMITTENT INCIDENT
Refer to EC-115, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
For circuit, refer to EC-165, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionEBS00M8D
HEATED OXYGEN SENSOR 1
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “MANU TRIG” and adjust “TRIGGER POINT” to 100% in “DATA MONITOR” mode with CONSULT-
II.
3. Select “HO2S1 (B1)” and “HO2S1 MNTR (B1)”.
4. Hold engine speed at 2,000 rpm under no load during the follow-
ing steps.
5. Touch “RECORD” on CONSULT-II screen.Water should not exist.
PBIB0500E
SEF646Y

EC-306
[QR25(WITH EURO-OBD)]
DTC P1144 HO2S1
6. Check the following.
●“HO2S1 MNTR (B1)” in “DATA MONITOR” mode changes
from “RICH” to “LEAN” to “RICH” 5 times in 10 seconds.
5 times (cycles) are counted as shown at right.
●“HO2S1 (B1)” voltage goes above 0.6V at least once.
●“HO2S1 (B1)” voltage goes below 0.3V at least once.
●“HO2S1 (B1)” 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.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes between ECM terminal 92 (HO2S1 signal) and engine ground.
3. Check the following with engine speed held at 2,000 rpm con-
stant under no load.
●The voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V
more than 5 times within 10 seconds.
●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.
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
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.
Removal and InstallationEBS00M8E
HEATED OXYGEN SENSOR 1
Refer to EM-24, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
SEF217YA
SEF648Y
PBIB0543E

DTC P1146 HO2S2
EC-307
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DTC P1146 HO2S2PFP:226A0
Component DescriptionEBS00M8F
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the heated oxygen sensor 1 are
shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor ModeEBS00M8G
Specification data are reference values.
ECM Terminals and Reference ValueEBS00M8H
Specification 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.
On Board Diagnosis LogicEBS00M8I
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxygen
storage capacity before the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the minimum voltage of sensor is
sufficiently low during the various driving condition such as fuel-cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
●Engine: After warming up
●Keeping the engine speed at
between 3,500 to 4,000 rpm for
one minute and at idle for one
minute under no loadRevving engine from idle up to 3,000
rpm quickly.0 - 0.3V ←→ Approx. 0.6 - 1.0V
HO2S2 MNTR (B1)
●Engine: After warming up
●Keeping the engine speed at
between 3,500 to 4,000 rpm for
one minute and at idle for one
minute under no loadRevving engine from idle up to 3,000
rpm quickly.LEAN←→ RICH
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
95 OR/BHeated oxygen sen-
sor 2[Engine is running]
●Warm-up condition
●Revving engine from idle up to 3,000 rpm quickly
after the following conditions are met.
●Keeping the engine speed between 3,500 and
4,000 rpm for one minute and at idle for one
minute under no load.0 - Approximately 1.0V
PBIB0554E

EC-308
[QR25(WITH EURO-OBD)]
DTC P1146 HO2S2
DTC Confirmation Procedure
EBS00M8J
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
●For the best results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30°C (32 to 86°F).
●Open engine hood before conducting following procedure.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least one minute under no
load.
4. Let engine idle for one minute.
5. Select “HO2S2 (B1) P1146” of “HO2S2” in “DTC WORK SUPPORT” mode with CONSULT-II and follow
the instruction of CONSULT-II.
6. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”.
If “NG” is displayed, refer to EC-311, "
Diagnostic Procedure" .
If “CAN NOT BE DIAGNOSED” is displayed, perform the following.
a. Turn ignition switch “OFF” and leave the vehicle in a cool place (soak the vehicle).
b. Turn ignition switch “ON” and select “COOLANTEMP/S” in “DATA MONITOR” mode with CONSULT-II.
c. Start engine and warm it up while monitoring “COOLANTEMP/S” indication on CONSULT-II.
d. When “COOLANTEMP/S” indication reaches to 70°C (158°F), go to step 3.
Overall Function CheckEBS00M8K
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a
DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least one minute under no
load.
4. Let engine idle for one minute.
5. Set voltmeter probes between ECM terminal 95 (HO2S2 signal) and engine ground.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1146
11 4 6Heated oxygen sensor
2 minimum voltage
monitoringThe minimum voltage from the sensor is not
reached to the specified voltage.
●Harness or connectors
(The sensor circuit is open or shorted)
●Heated oxygen sensor 2
●Fuel pressure
●Injectors
PBIB0818E

DTC P1146 HO2S2
EC-309
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6. 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 below 0.50V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in “D”
position with “OD” OFF (A/T), 3rd gear position (M/T).
The voltage should be below 0.50V at least once during this
procedure.
8. If NG, go to EC-311, "
Diagnostic Procedure" .
PBIB0550E

EC-310
[QR25(WITH EURO-OBD)]
DTC P1146 HO2S2
Wiring Diagram
EBS00M8L
TBWA0061E