Nissan Frontier D40. Manual - part 369

P0139 HO2S2

EC-167

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>> INSPECTION END

Component Inspection

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HEATED OXYGEN SENSOR 2

 With CONSULT-III

1.

Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.

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-III.

7.

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

±

25%.

“HO2S2 (B1)” should be above 0.73V 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.

• 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-III

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 74 (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 0.73V and below 0.18V at least
once during this procedure.
If the voltage can be confirmed at step 6, step 7 is not nec-
essary.

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 0.73V 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.

PBIB1920E

PBIB1197E

EC-168

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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).

P0171 FUEL INJECTION SYSTEM FUNCTION

EC-169

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P0171 FUEL INJECTION SYSTEM FUNCTION

On Board Diagnosis Logic

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With the Air-Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from A/F sensor 1. The ECM calculates
the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (the actual mixture ratio is too lean), the
ECM judges the condition as the fuel injection system malfunction and illuminates the MIL (2 trip detection
logic).

DTC Confirmation Procedure

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NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

 WITH CONSULT-III

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-III.

4.

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

5.

Start engine.
If it is difficult to start engine, the fuel injection system has a malfunction.
Performing the following procedure is advised.

a.

Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three-fourths (3/4) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.

b.

If engine starts, go to 

EC-170, "Diagnosis Procedure"

.

If engine does not start, check exhaust and intake air leakage visually.

6.

Keep engine at idle for at least 5 minutes.

7.

Check 1st trip DTC.

8.

The 1st trip DTC P0171 should be detected at this stage, if a malfunction exists. If so, go to 

EC-170,

"Diagnosis Procedure"

.

NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.

a.

Turn ignition switch OFF and wait at least 10 seconds.

b.

Start engine.

c.

Maintain the following conditions for at least 10 consecutive minutes.

Sensor

Input Signal to ECM

ECM 

function

Actuator

Air fuel ratio (A/F) sensor 1

Density of oxygen in exhaust gas
(Mixture ratio feedback signal)

Fuel injec-
tion control

Fuel injector

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

P0171
0171

Fuel injection system 
too lean

• Fuel injection system does not operate properly.
• The amount of mixture ratio compensation is too 

large. (The mixture ratio is too lean.)

• Intake air leaks
• Air fuel ratio (A/F) sensor 1
• Fuel injector
• Exhaust gas leaks
• Incorrect fuel pressure
• Lack of fuel
• Mass air flow sensor
• Incorrect PCV hose connection

EC-170

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P0171 FUEL INJECTION SYSTEM FUNCTION

Hold the accelerator pedal as steady as possible.

CAUTION:

Always drive vehicle at a safe speed.

d.

Check 1st trip DTC.

e.

If 1st trip DTC is detected, go to 

EC-170, "Diagnosis Procedure"

.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Disconnect mass air flow sensor harness connector.

4.

Restart engine and let it idle for at least 5 seconds.

5.

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

6.

Select Service $03 with GST. Check that DTC P0102 is
detected.

7.

Select Service $04 with GST and erase the DTC P0102.

8.

Start engine.
If it is difficult to start engine, the fuel injection system has a mal-
function.
Performing the following procedure is advised.

a.

Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three-fourths (3/4) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.

b.

If engine starts, go to 

EC-170, "Diagnosis Procedure"

If engine does not start, check exhaust and intake air leakage visually.

9.

Keep engine at idle for at least 5 minutes.

10. Check 1st trip DTC.

11. The 1st trip DTC P0171 should be detected at this stage, if a malfunction exists. If so, go to 

EC-170,

"Diagnosis Procedure"

.

NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.

a.

Turn ignition switch OFF and wait at least 10 seconds.

b.

Start engine.

c.

Maintain the following conditions for at least 10 consecutive minutes.
Hold the accelerator pedal as steady as possible.

CAUTION:

Always drive vehicle at a safe speed.

d.

Check 1st trip DTC.

e.

If 1st trip DTC is detected, go to 

EC-170, "Diagnosis Procedure"

.

Diagnosis Procedure

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1.

CHECK EXHAUST GAS LEAK

1.

Start engine and run it at idle.

VHCL SPEED SE

50 - 120 km/h (31 - 75 MPH)

VHCL SPEED SE

50 - 120 km/h (31 - 75 MPH)

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