Nissan X-Trail 32. Manual - part 776

P0138 HO2S2

EC-233

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Refer to 

EC-234, "Component Inspection"

.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 6.

6.

REPLACE HEATED OXYGEN SENSOR 2

Replace malfunctioning heated oxygen sensor 2. Refer to 

EX-6, "Exploded View"

.

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.

>> INSPECTION END

7.

CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

1.

Start engine and warm it up to the normal operating temperature.

2.

Clear the mixture ratio self-learning value. Refer to 

EC-148, "Work Procedure"

.

3.

Run engine for at least 10 minutes at idle speed.

Is the 1st trip DTC P0172 detected? Is it difficult to start engine?

YES

>> Perform trouble diagnosis for DTC P0172. Refer to 

EC-249, "Diagnosis Procedure"

.

NO

>> GO TO 8.

8.

CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Disconnect heated oxygen sensor 2 (HO2S2) harness connector.

4.

Check the continuity between HO2S2 harness connector and ECM harness connector.

5.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> Repair or replace malfunctioning part.

9.

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check the continuity between HO2S2 harness connector and ECM harness connector.

2.

Check the continuity between HO2S2 harness connector and ground, or ECM harness connector and
ground.

+

−

Continuity

HO2S2

ECM

Connector

Terminal

Connector

Terminal

CVT models

F44

1

F8

59

Existed

M/T models

F125

+

−

Continuity

HO2S2

ECM

Connector

Terminal

Connector

Terminal

CVT models

F44

2

F8

57

Existed

M/T models

F125

EC-234

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

P0138 HO2S2

3.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> GO TO 10.

NO

>> Repair or replace malfunctioning part.

10.

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-234, "Component Inspection"

.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 11.

11.

REPLACE HEATED OXYGEN SENSOR 2

Replace malfunctioning heated oxygen sensor 2. Refer to 

EX-6, "Exploded View"

.

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.

>> INSPECTION END

Component Inspection

INFOID:0000000010775151

1.

INSPECTION START

Will CONSULT be used?

Will CONSULT be used?

YES

>> GO TO 2.

NO

>> GO TO 3.

2.

CHECK HEATED OXYGEN SENSOR 2-1

WITH CONSULT

1.

Select “DATA MONITOR” mode with CONSULT.

2.

Start engine and warm it up to the normal operating temperature.

3.

Turn ignition switch OFF and wait at least 10 seconds.

4.

Restart engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no
load.

5.

Let engine idle for 1 minute.

6.

Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select “HO2S2 (B1)” as the monitor item with
CONSULT.

7.

Check “HO2S2 (B1)” at idle speed when adjusting “FUEL INJECTION” to 

±

 25%.

“HO2S2 (B1)/(B2)” should be above 0.68 V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.18 V at least once when the “FUEL INJECTION” is +25%.

Is the inspection result normal?

YES

>> INSPECTION END

+

Ground

Continuity

HO2S2

Connector

Terminal

CVT models

F44

2

Ground

Not existed

M/T models

F125

+

Ground

Continuity

ECM

Connector

Terminal

F8

57

Ground

Not existed

P0138 HO2S2

EC-235

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

NO

>> GO TO 6.

3.

CHECK HEATED OXYGEN SENSOR 2-2

WITHOUT CONSULT

1.

Start engine and warm it up to the normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Restart engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no
load.

4.

Let engine idle for 1 minute.

5.

Check the voltage between ECM harness connector terminals under the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 4.

4.

CHECK HEATED OXYGEN SENSOR 2-3

WITHOUT CONSULT

Check the voltage between ECM harness connector terminals under the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 5.

5.

CHECK HEATED OXYGEN SENSOR 2-4

WITHOUT CONSULT

Check the voltage between ECM harness connector terminals under the following conditions.

CAUTION:

Always drive vehicle at a safe speed.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 6.

6.

REPLACE HEATED OXYGEN SENSOR 2

ECM

Condition

Voltage

Connector

+

–

Terminal

F8

57

59

Revving up to 4,000 rpm quickly under no load 
at least 10 times. (Depress and release the ac-
celerator pedal as quickly as possible.)

The voltage should be above 0.77 V at 
least once during this procedure.
The voltage should be below 0.18 V at 
least once during this procedure.

ECM

Condition

Voltage

Connector

+

–

Terminal

F8

57

59

Keeping engine at idle for 10 minutes.

The voltage should be above 0.77 V at 
least once during this procedure.
The voltage should be below 0.18 V at 
least once during this procedure.

ECM

Condition

Voltage

Connector

+

–

Terminal

F8

57

59

Coasting from 80 km/h (50 MPH) with selector 
lever in the D position.

The voltage should be above 0.77 V at 
least once during this procedure.
The voltage should be below 0.18 V at 
least once during this procedure.

EC-236

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

P0138 HO2S2

Replace malfunctioning heated oxygen sensor 2. Refer to 

EX-6, "Exploded View"

.

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.

>> INSPECTION END