Nissan Frontier. Manual - part 412

P0139 HO2S2

EC-219

< DTC/CIRCUIT DIAGNOSIS >

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Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to  

EC-219, "Diagnosis Procedure"

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Overall Function Check

INFOID:0000000009480880

Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st

trip DTC might not be confirmed.

1.

PERFORM COMPONENT FUNCTION CHECK-1

Without CONSULT

1. Start engine and warm it up to 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 as per the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

PERFORM COMPONENT FUNCTION CHECK-2

Check the voltage between ECM harness connector and ground as per the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 3.

3.

PERFORM COMPONENT FUNCTION CHECK-3

Check the voltage between ECM harness connector and ground as per the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to 

EC-219, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000009480881

1.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

ECM

Condition

Voltage

Connector

+

−

Terminal

F56

33

35

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

The voltage should be above 0.96 V 
at least once during this procedure.

ECM

Condition

Voltage

Connector

+

−

Terminal

F56

33

35

Keeping engine speed at idle for 10 
minutes

The voltage should be above 0.96 V 
at least once during this procedure.

ECM

Condition

Voltage

Connector

+

−

Terminal

F56

33

35

Coasting from 80 km/h (50 MPH) in 
D position with O/D OFF (A/T), 4th 
gear position (M/T)

The voltage should be above 0.96 V 
at least once during this procedure.

EC-220

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

P0139 HO2S2

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

EC-149, "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 P0171 or P0172 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.

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-55, "On Board Diagnosis

Function"

 (Without CONSULT) or 

EC-58, "CONSULT Function"

(With CONSULT).

7. Make sure DTC P0000 is displayed.

8. 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 or No

Yes

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

EC-228

 or 

EC-233

.

No

>> GO TO 3.

3.

CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Disconnect heated oxygen sensor 2 harness connector.

4. Check harness continuity between ECM terminal 35 and HO2S2

terminal 4.

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, short to ground or short to power in

harness or connectors.

BBIA0614E

BBIA0622E

Continuity should exist.

BBIA0613E

P0139 HO2S2

EC-221

< DTC/CIRCUIT DIAGNOSIS >

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4.

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Check harness continuity between ECM terminal 33 and HO2S2 terminal 1.

Refer to Wiring Diagram.

2. Check harness continuity between ECM terminal 33 or HO2S2 terminal 1 and ground.

Refer to Wiring Diagram.

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

OK

>> GO TO 5.

NG

>> Repair open circuit, 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 heated oxygen sensor 2. Refer to 

EX-5, "Exploded View"

.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000009480882

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)” as the monitor item with

CONSULT.

7. Check “HO2S2 (B1)” at idle speed when adjusting “FUEL INJECTION” to 

±25%.

Reference data

“HO2S2 (B1)” should be above  (0.78V) at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)” should be below  (0.18V) 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.

Continuity should exist.

Continuity should not exist.

JSBIA3451ZZ

EC-222

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

P0139 HO2S2

• Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor

Thread Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize

lubricant (commercial service tool).

 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. Set voltmeter probes between ECM terminal 33 (HO2S2 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 0.78V and below 0.18V at least once during this procedure.

If the voltage can be confirmed at step 6, step 7 is not necessary.

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 with OD “OFF” (A/T), 4th gear position (M/T).

The voltage should be above 0.78V and below 0.18V 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 [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant

(commercial service tool).