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Nissan Altima L32. Manual - part 408

P0139 HO2S2

EC-753

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0139 HO2S2

Description

INFOID:0000000004349721

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 air fuel ratio (A/F) 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 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.

DTC Logic

INFOID:0000000004349722

DTC DETECTION LOGIC

The heated oxygen sensor 2 has a much longer switching time

between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-

gen storage capacity of the three way catalyst (mamifold) causes the

longer switching time. To judge the malfunctions of heated oxygen

sensor 2, ECM monitors whether the switching response of the sen-

sor's voltage is faster than specified during the various driving condi-

tion such as fuel-cut.

DTC CONFIRMATION PROCEDURE

INSPECTION START

Do you have CONSULT-III?
Do you have CONSULT-III?

YES

>> GO TO 2.

>> GO TO 5.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at

least 10 seconds before conducting the next test.

>> GO TO 3.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT-III

1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.

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

SEF327R

SEF302U

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0139

Heated oxygen sensor 2
circuit slow response

It takes more time for the sensor to respond be-
tween rich and lean than the specified time.

• Harness or connectors

(The sensor circuit is open or shorted)

• Heated oxygen sensor 2
• Fuel pressure
• Fuel injector
• Intake air leaks

EC-754

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0139 HO2S2

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

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. Open engine hood.

7. Select “HO2S2 (B1) P0139” of “HO2S2” in “DTC WORK SUPPORT” mode with CONSULT-III.

8. Follow the instruction of CONSULT-III.

NOTE:

It will take at most 10 minutes until “COMPLETED” is displayed.

9. Touch “SELF-DIAG RESULT”.
Which is displayed on CONSULT-III?

>> INSPECTION END

>> GO TO 4.

CAN NOT BE DIAGNOSED>>GO TO 4.

PERFORM THE RESULT OF DTC CONFIRMATION PROCEDURE

1. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).

2. Perform DTC CONFIRMATION PROCEDURE again.

>> GO TO 3.

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to

EC-754, "Component Function Check"

NOTE:

Use component function check to check the overall function of the heated oxygen sensor 2 circuit. During this

check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?

YES

>> INSPECTION END

>> Go to

EC-755, "Diagnosis Procedure"

Component Function Check

INFOID:0000000004349723

PERFORM COMPONENT FUNCTION CHECK-I

Without CONSULT-III

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 1 minute under no load.

4. Let engine idle for 1 minute.

5. Check the voltage between ECM harness connector and ground

under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

>> GO TO 2.

PERFORM COMPONENT FUNCTION CHECK-II

ECM

Ground

Condition

Voltage

Con-

nector

Termi-

nal

F13

(HO2S

2 sig-

nal)

Ground

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

The voltage should be above
0.30V at least once during this
procedure.

JMBIA1586ZZ

P0139 HO2S2

EC-755

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

Check the voltage between ECM harness connector and ground

under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

>> GO TO 3.

PERFORM COMPONENT FUNCTION CHECK-III

Check the voltage between ECM harness connector and ground

under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

>> Go to

EC-755, "Diagnosis Procedure"

Diagnosis Procedure

INFOID:0000000004349724

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection E9. Refer to Ground Inspection in

GI-45, "Circuit Inspection"

Is the inspection result normal?

YES

>> GO TO 2.

>> Repair or replace ground connection.

CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

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

EC-568, "MIXTURE RATIO SELF-LEARNING VALUE

CLEAR : Special Repair Requirement"

2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0172 detected? Is it difficult to start engine?

YES

>> Perform trouble diagnosis for DTC P0171 or P0172. Refer to

EC-759, "DTC Logic"

EC-763,

"DTC Logic"

>> GO TO 3.

CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect heated oxygen sensor 2 harness connector.

3. Disconnect ECM harness connector.

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

ECM

Ground

Condition

Voltage

Con-

nector

Termi-

nal

F13

(HO2S

2 sig-

nal)

Ground

Keeping engine speed
at idle for 10 minutes

The voltage should be
above 0.30V at least once
during this procedure.

JMBIA1587ZZ

ECM

Ground

Condition

Voltage

Con-

nector

Termi-

nal

F13

(HO2S

2 sig-

nal)

Ground

Coasting from 80 km/h (50
MPH) in D position (CVT),
4th gear position (M/T)

The voltage should be
above 0.30V at least
once during this proce-
dure.

JMBIA1588ZZ

EC-756

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0139 HO2S2

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

YES

>> GO TO 4.

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

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 or ECM harness connector and ground.

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

YES

>> GO TO 5.

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

CHECK HEATED OXYGEN SENSOR 2

Refer to

EC-756, "Component Inspection"

Is the inspection result normal?

YES

>> GO TO 7.

>> GO TO 6.

REPLACE HEATED OXYGEN SENSOR 2

Replace heated oxygen sensor 2.

CAUTION:

• Discard any 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 sensor, clean exhaust system threads using oxygen sensor thread cleaner tool

[commercial service tool: (J-43897-18) or J43897-12] and approved anti-seize lubricant (commercial

service tool).

>> INSPECTION END

CHECK INTERMITTENT INCIDENT

Refer to

GI-42, "Intermittent Incident"

>> INSPECTION END

Component Inspection

INFOID:0000000004349725

INSPECTION START

Do you have CONSULT-III?
Do you have CONSULT-III?

YES

>> GO TO 2.

HO2S2

ECM

Continuity

Connector Terminal Connector Terminal

F42

F13

Existed

HO2S2

ECM

Continuity

Connector Terminal Connector Terminal

F42

F13

Existed

HO2S2

ECM

Ground

Continuity

Connector Terminal Connector Terminal

F42

F13

Ground Not existed

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