Nissan Xterra. Manual - part 273

EC-218

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

P0138, P0158 HO2S2

1. Disconnect heated oxygen sensor 2 harness connector.

2. Disconnect ECM harness connector.

3. Check harness continuity between HO2S2 terminal 1 and ECM terminal 59.

Refer to Wiring Diagram.

4. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 3.

NG

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

3.

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Check harness continuity between ECM terminal and HO2S2 terminal as follows.

Refer to Wiring Diagram.

2. Check harness continuity between the following terminals and ground.

Refer to Wiring Diagram.

Continuity should exist.

BBIA0540E

DTC

Terminals

Bank

ECM

Sensor

P0138

57

2

1

P0158

58

2

2

Continuity should exist.

DTC

Terminals

Bank

ECM

Sensor

P0138

57

2

1

P0158

58

2

2

Continuity should not exist.

P0138, P0158 HO2S2

EC-219

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

3. Also check harness for short to power.
OK or NG

OK

>> GO TO 4.

NG

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

4.

CHECK HO2S2 CONNECTOR FOR WATER

Check connectors for water.

OK or NG

OK

>> GO TO 5.

NG

>> Repair or replace harness or connectors.

5.

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-221, "Component Inspection"

.

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning heated oxygen sensor 2. Refer to 

EX-5, "Exploded View"

.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

PROCEDURE FOR MALFUNCTION B

1.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

2. Loosen and retighten three ground screws on the body. Refer to 

EC-152, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CLEAR THE SELF-LEARNING DATA

 With CONSULT

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

2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT.

3. Clear the self-learning control coefficient by touching “CLEAR”.

4. Run engine for at least 10 minutes at idle speed.

Is the 1st trip DTC P0172 or P0175 detected?

Is it difficult to start engine?

 Without CONSULT

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

2. Turn ignition switch OFF.

Water should not exist.

BBIA0539E

EC-220

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

P0138, P0158 HO2S2

3. Disconnect mass air flow sensor harness connector, and restart

and run engine for at least 5 seconds at idle speed.

4. Stop engine and reconnect mass air flow sensor harness con-

nector.

5. Check DTC P0102 is displayed.

6. Erase the DTC memory. Refer to 

EC-50, "On Board Diagnosis

Function"

 (Without CONSULT) or 

EC-53, "CONSULT Function"

(With CONSULT).

7. Check DTC P0000 is displayed.

8. Run engine for at least 10 minutes at idle speed.

Is the 1st trip DTC P0172 or P0175 detected?

Is it difficult to start engine?

Yes or No

Yes

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

EC-241, "On Board Diagnosis Logic"

.

No

>> GO TO 3.

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 harness continuity between HO2S2 terminal 1 and ECM terminal 59.

Refer to Wiring Diagram.

5. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 4.

NG

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

4.

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Check harness continuity between ECM terminal and HO2S2 terminal as follows.

Refer to Wiring Diagram.

BBIA0541E

Continuity should exist.

BBIA0540E

P0138, P0158 HO2S2

EC-221

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

2. Check harness continuity between the following terminals and ground.

Refer to Wiring Diagram.

3. Also check harness for short to power.
OK or NG

OK

>> GO TO 5.

NG

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

5.

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-221, "Component Inspection"

.

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning heated oxygen sensor 2. Refer to 

EX-5, "Exploded View"

.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000009483932

HEATED OXYGEN SENSOR 2

 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. 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, and select “HO2S2 (B1)/(B2)” as the monitor item

with CONSULT.

DTC

Terminals

Bank

ECM

Sensor

P0138

57

2

1

P0158

58

2

2

Continuity should exist.

DTC

Terminals

Bank

ECM

Sensor

P0138

57

2

1

P0158

58

2

2

Continuity should not exist.