Nissan Pathfinder. Manual — part 483

EC-238

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0138, P0158 HO2S2

4.

CHECK HEATED OXYGEN SENSOR 2-II

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-III

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

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace malfunctioning heated oxygen sensor 2. Refer to

EM-31, "Removal and Installation

(bank 2)"

,

EM-33, "Removal and Installation (bank 1)"

.

ECM

Condition

Voltage

Connector

+

–

Terminal

F52

57

59

Keeping engine at idle for
10 minutes

The voltage should be above 0.68 V at least once during this
procedure.
The voltage should be below 0.18 V at least once during this
procedure.

58

ECM

Condition

Voltage

Connector

+

–

Terminal

F52

57

59

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

The voltage should be above 0.68 V at least once dur-
ing this procedure.
The voltage should be below 0.18 V at least once dur-
ing this procedure.

58

P0139, P0159 HO2S2

EC-239

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

C

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F

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EC

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P0139, P0159 HO2S2

DTC Logic

INFOID:0000000009178162

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 1 causes the longer

switching time. To judge the malfunctions of heated oxygen sensor

2, ECM monitors whether the switching response of the sensor's

voltage is faster than specified during various driving conditions such

as fuel cut.

DTC CONFIRMATION PROCEDURE

1.

INSPECTION START

Do you have CONSULT?
Do you have CONSULT?

YES

>> GO TO 2.

NO

>> GO TO 7.

2.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting the next test.

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

2. Turn ignition switch ON.

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

TESTING CONDITION:

For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30

°C (32 to 86°F).

>> GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT

1. Turn ignition switch ON and 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. Turn ignition switch ON.

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

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

7. Let engine idle for 1 minute.

8. Make sure that “COOLANT TEMP/S” indicates more than 70

°C (158°F).

9. Drive the vehicle in a proper gear at 60 km/h (38MPH) and maintain the speed.

CAUTION:

SEF302U

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0139

HO2S2 (B1)
(O2 sensor circuit slow re-
sponse bank 1 sensor 2)

The switching time between rich and lean of a
heated oxygen sensor 2 signal delays more
than the specified time computed by ECM.

• Harness or connectors

(The sensor circuit is open or shorted)

• Heated oxygen sensor 2
• Fuel system
• EVAP system
• Intake air system

P0159

HO2S2 (B2)
(O2 sensor circuit slow re-
sponse bank 2 sensor2)

EC-240

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0139, P0159 HO2S2

Always drive vehicle at a safe speed.

10. Release the accelerator pedal fully at least 5 seconds.

CAUTION:

• Enable the engine brake.

• Always drive carefully.

• Never apply brake when releasing the accelerator pedal.

11. Repeat step 9 and 10 at least 8 times.

12. Check the following item of “DATA MONITOR”.

Is “CMPLT” displayed on CONSULT screen?

YES

>> GO TO 6.

NO-1: “CMPLT” is not displayed on DIAG 1>>Perform DTC confirmation procedure again.

NO-2: “CMPLT” is not displayed on DIAG 2>>GO TO 4.

4.

PERFORM DTC WORK SUPPORT

1. Open engine hood.

2. Select “HO2S2 (B1) P0139” or “HO2S2 (B2) P0159” of “HO2S2” in “DTC WORK SUPPORT” mode with

CONSULT.

3. Start engine and follow the instruction of CONSULT display.

NOTE:

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

Is “COMPLETED” displayed on CONSULT screen?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

PERFORM DTC CONFIRMATION PROCEDURE AGAIN

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.

6.

PERFORM SELF-DIAGNOSIS

With CONSULT

Perform ECM self-diagnosis.
Is DTC “P0139” or “P0159” detected?

YES

>> Proceed to

EC-242, "Diagnosis Procedure"

.

NO

>> INSPECTION END

7.

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to

EC-241, "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

NO

>> Proceed to

EC-242, "Diagnosis Procedure"

.

Component Function Check

INFOID:0000000009178163

1.

PERFORM COMPONENT FUNCTION CHECK-I

Without CONSULT

DTC

Data monitor item

Status

P0139

HO2 S2 DIAG1 (B1)

CMPLT

HO2 S2 DIAG2 (B1)

P0159

HO2 S2 DIAG1 (B2)

HO2 S2 DIAG2 (B2)

P0139, P0159 HO2S2

EC-241

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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

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

3. Turn ignition switch ON.

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

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

6. Let engine idle for 1 minute.

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

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

PERFORM COMPONENT FUNCTION CHECK-II

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

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 3.

3.

PERFORM COMPONENT FUNCTION CHECK-III

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

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to

EC-242, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000009178164

1.

CLEAR MIXTURE RATIO SELF-LEARNING VALUE

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

EC-145, "Work Procedure"

.

2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected? Is it difficult to start engine?

YES

>> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to

EC-252, "DTC Logic"

or

EC-256, "DTC Logic"

.

NO

>> GO TO 2.

2.

CHECK HO2S2 GROUND CIRCUIT

1. Turn ignition switch OFF.

DTC

ECM

Condition

Voltage

Connector

+

–

Terminal

P0139

F52

57

59

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

A change of voltage should be more than
0.96 V for 1 second during this procedure.

P0159

58

DTC

ECM

Condition

Voltage

Connector

+

–

Terminal

P0139

F52

57

59

Keeping engine at idle for 10 min-
utes

A change of voltage should be more than
0.96 V for 1 second during this procedure.

P0159

58

DTC

ECM

Condition

Voltage

Connector

+

–

Terminal

P0139

F52

57

59

Coasting from 80 km/h (50 MPH) in
D position

A change of voltage should be more than
0.96 V for 1 second during this procedure.

P0159

58