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Nissan Titan. Manual - part 233

P0139, P0159 HO2S2

EC-233

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

P0139, P0159 HO2S2

Component Description

INFOID:0000000009886643

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.

On Board Diagnosis Logic

INFOID:0000000009886644

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

INFOID:0000000009886645

INSPECTION START

Do you have CONSULT?
Do you have CONSULT?

YES

>> GO TO 2.

>> GO TO 7.

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.

SEF327R

SEF302U

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0139

Heated oxygen sensor 2
(bank 1) circuit slow re-
sponse

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

Heated oxygen sensor 2
(bank 2) circuit slow re-
sponse

EC-234

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

P0139, P0159 HO2S2

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 “COOLAN 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:

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.

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.

>> GO TO 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.

PERFORM SELF-DIAGNOSIS

With CONSULT

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

YES

>> Proceed to

EC-236, "Diagnosis Procedure"

>> INSPECTION END

PERFORM COMPONENT FUNCTION CHECK

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-235

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

Perform component function check. Refer to

EC-235, "Overall 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

>> Proceed to

EC-236, "Diagnosis Procedure"

Overall Function Check

INFOID:0000000009886646

PERFORM COMPONENT FUNCTION CHECK-I

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. 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 terminals under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

>> GO TO 2.

PERFORM COMPONENT FUNCTION CHECK-II

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

Is the inspection result normal?

YES

>> INSPECTION END

>> Proceed to

EC-236, "Diagnosis Procedure"

DTC

ECM

Condition

Voltage

Connector

Terminal

–

P0139

F54

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

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

P0159

DTC

ECM

Condition

Voltage

Connector

Terminal

–

P0139

F54

Keeping engine at idle for 10 minutes

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

P0159

DTC

ECM

Condition

Voltage

Connector

–

Terminal

P0139

F54

Coasting from 80 km/h (50 MPH) on the
suitable gear position

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

P0159

EC-236

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

P0139, P0159 HO2S2

Diagnosis Procedure

INFOID:0000000009886647

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection M95. 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-49, "CONSULT Function"

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-240, "On Board

Diagnosis Logic"

EC-245, "On Board Diagnosis Logic"

>> GO TO 3.

CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect heated oxygen sensor 2 (HO2S2) harness connector.

3. Disconnect ECM 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 4.

>> Repair open circuit, 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 and ground, or ECM harness connector and

ground.

DTC

HO2S2

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0139

F13

F54

Existed

P0159

F12

DTC

HO2S2

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0139

F13

F54

Existed

P0159

F12

DTC

HO2S2

Ground

Continuity

Bank

Connector

Terminal

P0139

F13

Ground

Not existed

P0159

F12

DTC

ECM

Ground

Continuity

Bank

Connector

Terminal

P0139

F54

Ground

Not existed

P0159

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