Nissan March K13. Manual - part 179

P0139 HO2S2

EC-177

< DTC/CIRCUIT DIAGNOSIS >

[HR12DE (TYPE 1)]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

YES

>> INSPECTION END

NO

>> GO TO 5.

5.

CHECK HEATED OXYGEN SENSOR 2-III

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

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace malfunctioning heated oxygen sensor 2. Refer to 

EX-5, "Exploded View"

.

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

F16

50

(HO2S2)

59

Coasting from 80 km/h (50 MPH) in 4th 
gear position

The voltage should be above 0.68 V at 
least once during this procedure.
The voltage should be below 0.36 V at 
least once during this procedure.

EC-178

< DTC/CIRCUIT DIAGNOSIS >

[HR12DE (TYPE 1)]

P0171 FUEL INJECTION SYSTEM FUNCTION

P0171 FUEL INJECTION SYSTEM FUNCTION

DTC Logic

INFOID:0000000005989279

DTC DETECTION LOGIC

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 the A/F sensor 1. The ECM calcu-
lates 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 lights up the MIL (2 trip detection logic).

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

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

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE-I

1.

Clear the mixture ratio self-learning value. Refer to 

EC-108, "Work Procedure"

.

2.

Start engine.

Is it difficult to start engine?

YES

>> GO TO 3.

NO

>> GO TO 4.

3.

RESTART ENGINE

If it is difficult to start engine, the fuel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three-fourths (3/4) or more, the control system may not start the engine.
Do not depress accelerator pedal too much.

Does engine start?

YES

>> Go to 

EC-179, "Diagnosis Procedure"

.

NO

>> Check exhaust and intake air leak visually.

4.

PERFORM DTC CONFIRMATION PROCEDURE-II

1.

Start engine and let it idle for at least 10 minutes.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-179, "Diagnosis Procedure"

.

NO

>> GO TO 5.

5.

PERFORM DTC CONFIRMATION PROCEDURE-III

Sensor

Input signal to ECM

ECM function

Actuator

A/F sensor 1

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

Fuel injection control

Fuel injector

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0171

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

P0171 FUEL INJECTION SYSTEM FUNCTION

EC-179

< DTC/CIRCUIT DIAGNOSIS >

[HR12DE (TYPE 1)]

C

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1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.

CAUTION:

Always drive at a safe speed.

3.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-179, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005989280

1.

CHECK EXHAUST GAS LEAK

1.

Start engine and run it at idle.

2.

Listen for an exhaust gas leak before three way catalyst (manifold).

Is exhaust gas leak detected?

YES

>> Repair or replace.

NO

>> GO TO 2.

2.

CHECK FOR INTAKE AIR LEAK AND PCV HOSE

1.

Listen for an intake air leak after the mass air flow sensor.

2.

Check PCV hose connection.

Intake air leak detected?

YES

>> Repair or replace.

NO

>> GO TO 3.

3.

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect corresponding A/F sensor 1 harness connector.

3.

Disconnect ECM harness connector.

4.

Check the continuity between A/F sensor 1 harness connector and ECM harness connector.

5.

Check the continuity between A/F sensor 1 harness connector or ECM harness connector and ground.

Engine speed

Engine speed in the freeze frame data 

±

 400 rpm

Vehicle speed

Vehicle speed in the freeze frame data 

±

 10 km/h (6 MPH)

Engine coolant temperature (T) condition

When the freeze frame data shows lower than 70

°

C (158

°

F),

T should be lower than 70

°

C (158

°

F).

When the freeze frame data shows higher than or equal to 70

°

C (158

°

F),

T should be higher than or equal to 70

°

C (158

°

F).

PBIB1216E

A/F sensor 1

ECM

Continuity

Connector

Terminal

Connector

Terminal

F50

1

F16

49

Existed

EC-180

< DTC/CIRCUIT DIAGNOSIS >

[HR12DE (TYPE 1)]

P0171 FUEL INJECTION SYSTEM FUNCTION

6.

Also check harness for short to power.

Is the inspection result normal?

YES

>> GO TO 4.

NO

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

4.

CHECK FUEL PRESSURE

1.

Release fuel pressure to zero. Refer to 

EC-113, "Work Procedure"

.

2.

Install fuel pressure gauge and check fuel pressure. Refer to 

EC-113, "Work Procedure"

.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

 CHECK FUEL HOSES AND FUEL TUBES

Check fuel hoses and fuel tubes for clogging.
Is the inspection result normal?

YES

>> Replace fuel level sensor unit, fuel filter and fuel pump assembly. Refer to 

FL-5, "Exploded View"

.

NO

>> Repair or replace

6.

CHECK MASS AIR FLOW SENSOR

With CONSULT-III

1.

Install all removed parts.

2.

Check “MASS AIRFLOW” in “DATA MONITOR” mode with CONSULT-III.

With GST

1.

Install all removed parts.

2.

Check mass air flow sensor signal in Service $01 with GST.

Is the measurement value within the specification?

YES

>> GO TO 7.

NO

>> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or

grounds. Refer to 

EC-137, "DTC Logic"

.

7.

CHECK FUNCTION OF FUEL INJECTOR

With CONSULT-III

1.

Start engine.

2.

Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT-III.

3.

Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT-III

1.

Let engine idle.

A/F sensor 1

ECM

Ground

Continuity

Connector

Terminal

Connector

Terminal

F50

1

F16

49

Ground

Not existed

At idling: Approximately 350 kPa (3.5 bar, 3.57 kg/cm

2

, 51 psi)

1.0 - 4.0 g·m/sec:

at idling

2.0 - 10.0 g·m/sec:

at 2,500 rpm

1.0 - 4.0 g·m/sec:

at idling

2.0 - 10.0 g·m/sec:

at 2,500 rpm