Nissan Sentra. Manual - part 383

EC-228

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

P0138 HO2S2

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

3. Also check harness for short to power.
Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace error-detected parts.

4.

CHECK HO2S2 INPUT SIGNAL CIRCUIT

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.

3. Also check harness for short to power.
Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair or replace error-detected parts.

5.

CHECK HEATED OXYGEN SENSOR 2

Check the heated oxygen sensor 2. Refer to 

EC-229, "Component Inspection (HO2S2)"

.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-39, "Intermittent Incident"

.

NO

>> Replace heated oxygen sensor 2. Refer to 

EX-5, "Exploded View"

.

6.

CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

1. Clear the mixture ratio self-learning value. Refer to 

EC-142, "Work Procedure"

.

2. 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-250, "DTC Logic"

.

NO

>> GO TO 7.

7.

CHECK HO2S2 GROUND CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect heated oxygen sensor 2 harness connector.

3. Disconnect ECM harness connector.

+

−

Continuity

HO2S2

ECM

Connector

Terminal

Connector

Terminal

F43

1

F24

23

Existed

+

−

Continuity

HO2S2

ECM

Connector

Terminal

Connector

Terminal

F43

2

F24

22

Existed

+

−

Continuity

HO2S2

Connector

Terminal

F43

2

Ground

Not existed

+

−

Continuity

ECM

Connector

Terminal

F24

22

Ground

Not existed

P0138 HO2S2

EC-229

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

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

5. Also check harness for short to ground and to power.
Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Repair or replace error-detected parts.

8.

CHECK HO2S2 INPUT SIGNAL CIRCUIT

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.

3. Also check harness for short to power.
Is the inspection result normal?

YES

>> GO TO 9.

NO

>> Repair open circuit or short to ground or short to power in harness or connectors.

9.

CHECK HEATED OXYGEN SENSOR 2

Check the heated oxygen sensor 2. Refer to 

EC-229, "Component Inspection (HO2S2)"

.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-39, "Intermittent Incident"

.

NO

>> Replace heated oxygen sensor 2. Refer to 

EX-5, "Exploded View"

.

Component Inspection (HO2S2)

INFOID:0000000009758489

1.

INSPECTION START

Do you have CONSULT?
Do you have CONSULT?

YES

>> GO TO 2.

NO

>> GO TO 3.

2.

CHECK HEATED OXYGEN SENSOR 2

With CONSULT

+

−

Continuity

HO2S2

ECM

Connector

Terminal

Connector

Terminal

F43

1

F24

23

Existed

+

−

Continuity

HO2S2

ECM

Connector

Terminal

Connector

Terminal

F43

2

F24

22

Existed

+

−

Continuity

HO2S2

Connector

Terminal

F43

2

Ground

Not existed

+

−

Continuity

ECM

Connector

Terminal

F24

22

Ground

Not existed

EC-230

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

P0138 HO2S2

1. Turn ignition switch ON and select “DATA MONITOR” mode of “ENGINE” using CONSULT.

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

3. Turn ignition switch OFF and wait at least 10 seconds.

4. Start 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 of “ENGINE” using CONSULT, 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)” should be above 0.72 V at least once when the “FUEL INJECTION” is + 25%.

“HO2S2 (B1)” should be below 0.18 V at least once when the “FUEL INJECTION” is 

− 25%.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace heated oxygen sensor 2. Refer to 

EX-5, "Exploded View"

.

3.

CHECK HEATED OXYGEN SENSOR 2-1

Without CONSULT

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 1 minute under no load.

4. Let engine idle for 1 minute.

5. Check the voltage between ECM harness connector and ground as per the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 4.

4.

CHECK HEATED OXYGEN SENSOR 2-2

Check the voltage between ECM harness connector and ground as per the following condition.

JPBIA5998GB

ECM

Condition

Voltage

Connector

+

−

Terminal

F24

22

23

Revving up to 4,000 rpm under 
no load at least 10 times

The voltage should be above 
0.72 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

F24

22

23

Keeping engine speed at idle for 
10 minutes

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

P0138 HO2S2

EC-231

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

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Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 5.

5.

CHECK HEATED OXYGEN SENSOR 2-3

Check the voltage between ECM harness connector and ground as per the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace heated oxygen sensor 2. Refer to 

EX-5, "Exploded View"

.

ECM

Condition

Voltage

Connector

+

−

Terminal

F24

22

23

Coasting from 80 km/h (50 
MPH) in D position (CVT), 5th 
position (6MT)

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