2001 NISSAN X-TRAIL sensor oxygen

HO2S2 HEATER
EC-665
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3.DETECT MALFUNCTIONING PART
Check the following.
●Harness connectors E60, F36
●Fuse block (J/B) connector E103
●10A fuse
●Harness for open or short between heated oxygen sensor 2 and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 4 and HO2S2 terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 2 HEATER
Refer to EC-666, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace heated oxygen sensor 2.
6.CHECK INTERMITTENT INCIDENT
Refer to EC-506, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.

EC-666
[QR25(WITHOUT EURO-OBD)]
HO2S2 HEATER
Component Inspection
EBS00NCH
HEATED OXYGEN SENSOR 2 HEATER
1. Check resistance between HO2S2 terminals as follows.
2. If NG, replace heated oxygen sensor 2.
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 sur-
face 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 InstallationEBS00NCI
HEATED OXYGEN SENSOR 2
Refer to EX-2, "EXHAUST SYSTEM" .
Terminal No. Resistance
1 and 4 2.3 - 4.3 Ω at 25°C (77°F)
2 and 1, 3, 4
∞Ω
(Continuity should not exist)
3 and 1, 2, 4
PBIB0542E

HO2S1
EC-671
[QR25(WITHOUT EURO-OBD)]
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HO2S1PFP:22690
Component DescriptionEBS00NCO
The heated oxygen sensor 1 is placed into the front tube. 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 ModeEBS00NCP
Specification data are reference values.
ECM Terminals and Reference ValueEBS00NCQ
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)

HO2S1
EC-673
[QR25(WITHOUT EURO-OBD)]
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Diagnostic ProcedureEBS00NCS
1.CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select "HO2S1 MNTR (B1)" in "DATA MONITOR" mode with CONSULT-II.
3. Keep the engine speed at 2,000 rpm under no load, and make
sure that the monitors fluctuate between LEAN and RICH more
than five times in 10 seconds.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine and wait at least 10 seconds.
3. Set ECM in "Diagnostic test mode - II (Heated oxygen sensor 1 monitor)".
Refer to EC-459, "
DIAGNOSTIC TEST MODE II — HEATED OXYGEN SENSOR 1 MONITOR" .
4. Keep the engine speed at 2,000 rpm under no load, and make
sure that the MI comes ON more than five times in 10 seconds.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2.INSPECTION START
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 3. 1 time: RICH → LEAN → RICH
2 times: RICH → LEAN → RICH → LEAN →RICH
SEF820Y
SAT652J
PBIB0494E

EC-674
[QR25(WITHOUT EURO-OBD)]
HO2S1
3. CHECK HO2S1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect HO2S1 harness connector.
2. Check harness continuity between HO2S1 terminal 3 and
ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to power in harness or con-
nectors.
4. CHECK HO2S1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 92 and HO2S1 terminal 2.
Refer to Wiring Diagram.
3. Check harness continuity between ECM terminal 92 or HO2S1 terminal 2 and ground.
Refer to Wiring Diagram.
4. Also check harness for 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 HEATED OXYGEN SENSOR 1
Refer to EC-674, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace heated oxygen sensor 1.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-506, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS00NCT
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. Continuity should exist.
PBIB0500E
Continuity should exist.
Continuity should not exist.

HO2S1
EC-675
[QR25(WITHOUT EURO-OBD)]
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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.
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.
SEF646Y
SEF217YA
SEF648Y
PBIB0543E

EC-676
[QR25(WITHOUT EURO-OBD)]
HO2S1
●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 InstallationEBS00NCU
HEATED OXYGEN SENSOR 1
Refer to EM-24, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .

HO2S2
EC-677
[QR25(WITHOUT EURO-OBD)]
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HO2S2PFP:226A0
Component DescriptionEBS00NCV
The heated oxygen sensor 2, after three way catalyst, 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 ModeEBS00NCW
Specification data are reference values.
ECM Terminals and Reference ValueEBS00NCX
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.
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 minutes 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 minutes 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