Infiniti M45 (Y34). Manual - part 393

DTC P0139, P0159 HO2S2

EC-261

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2. 

CLEAR THE SELF-LEARNING DATA

 With CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

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

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 P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?

 Without CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF.

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.

Make sure DTC P0102 is displayed.

6.

Erase the DTC memory. Refer to 

EC-62, "HOW TO ERASE

EMISSION-RELATED DIAGNOSTIC INFORMATION"

 .

7.

Make sure DTC P0000 is displayed.

8.

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 or No

Yes

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

EC-266

  or 

EC-275

 .

No

>> GO TO 3.

SEF968Y

PBIB1119E

EC-262

DTC P0139, P0159 HO2S2

3. 

CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect heated oxygen sensor 2 harness connector.

3.

Check harness continuity between HO2S2 terminal 4 and ground.
Refer to Wiring Diagram.

4.

Also check harness for short to power.

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 4.

4. 

CHECK HEATED OXYGEN SENSOR 2

Check the following.

●

Harness connectors E315, F5

●

joint connector-29

●

harness for open or short between HO2S2 and ground

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

Continuity should exist.

PBIB0018E

DTC P0139, P0159 HO2S2

EC-263

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5. 

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Disconnect ECM harness connector.

2.

Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.

3.

Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.

4.

Also check harness for short to power.

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

6. 

CHECK HEATED OXYGEN SENSOR 2

Check the following.

●

Harness connectors E315, F5

●

harness for open or short between HO2S2 and ground

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

7. 

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-263, "Component Inspection"

 .

OK or NG

OK

>> GO TO 8.

NG

>> Replace malfunctioning heated oxygen sensor 2.

8. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Component Inspection

ABS002HS

HEATED OXYGEN SENSOR 2

 With CONSULT-II

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 engine speed between 3,500 and 4,000 rpm for 1 minute under no load.

4.

Let engine idle for 1 minute.

DTC

Terminals

Bank

ECM

Sensor

P0139

123

1

1

P0159

124

1

2

Continuity should exist.

DTC

Terminals

Bank

ECM

Sensor

P0139

123

1

1

P0159

124

1

2

Continuity should not exist.

EC-264

DTC P0139, P0159 HO2S2

5.

Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select
“HO2S2 (B1)/(B2)” as the monitor item with CONSULT-II.

6.

Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to 

±

25%.

“HO2S2 (B1)/(B2)” should be above 0.58V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.48V at least once when the “FUEL INJECTION” is 

−

25%.

CAUTION:

●

Discard any heated oxygen 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 oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

 Without CONSULT-II

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 engine speed between 3,500 and 4,000 rpm for 1 minute under no load.

4.

Let engine idle for 1 minute.

5.

Set voltmeter probes between ECM terminal 123 [HO2S2 (B1) signal] or 124 [HO2S2 (B2) signal] and
ground.

6.

Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.58V at least once during this
procedure.
If the voltage is above 0.58V at step 6, step 7 is not neces-
sary.

7.

Keep vehicle at idling for 10 minutes, then check voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.48V at least once during this
procedure.

8.

If NG, replace heated oxygen sensor 2.

CAUTION:

●

Discard any heated oxygen 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 oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

PBIB1918E

PBIB1153E

PBIB2079E