Nissan Cube. Manual - part 332

EC-214

< DTC/CIRCUIT DIAGNOSIS >

[MR18DE]

P014C, P014D, P015A, P015B A/F SENSOR 1

5.

Also check harness for short to power.

Is the inspection result normal?

YES

>> GO TO 9.

NO

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

9.

CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER

Refer to 

EC-140, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 10.

NO

>> GO TO 13.

10.

CHECK MASS AIR FLOW SENSOR

Refer to 

EC-150, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 11. 

NO

>> Replace mass air flow sensor. Refer to 

EM-24, "Exploded View"

.

11.

CHECK PCV VALVE

Refer to 

EC-424, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 12.

NO

>> Repair or replace PCV valve. Refer to 

EM-40, "Exploded View"

.

12.

CHECK INTERMITTENT INCIDENT

Perform 

GI-40, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> GO TO 13.

NO

>> Repair or replace.

13.

REPLACE AIR FUEL RATIO (A/F) SENSOR 1

Replace air fuel ratio (A/F) sensor 1. Refer to 

EM-29, "Exploded View"

.

CAUTION:

• Discard any 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 sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner

[commercial service tool (J-43897-18 or J43897-12)] and approved Anti-seize Lubricant (commercial
service tool).

>> INSPECTION END

ECM

Ground

Continuity

Connector

Terminal

F8

49

Ground

Not existed

53

P0171 FUEL INJECTION SYSTEM FUNCTION

EC-215

< DTC/CIRCUIT DIAGNOSIS >

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P0171 FUEL INJECTION SYSTEM FUNCTION

DTC Logic

INFOID:0000000009947334

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 sensors 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-22, "MIXTURE RATIO SELF-LEARNING VALUE

CLEAR : Special Repair Requirement"

.

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 does not start the
engine. Do not depress accelerator pedal too much.
Does engine start?

YES

>> Go to 

EC-216, "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 5 minutes.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-216, "Diagnosis Procedure"

.

NO

>> GO TO 5.

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

EC-216

< DTC/CIRCUIT DIAGNOSIS >

[MR18DE]

P0171 FUEL INJECTION SYSTEM FUNCTION

5.

PERFORM DTC CONFIRMATION PROCEDURE-III

1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Start engine.

3.

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.

4.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-216, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009947335

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

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

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 and ground, or ECM harness connector
and ground.

VHCL SPEED SE

50 - 120 km/h (31 - 75 MPH)

PBIB1216E

A/F sensor 1

ECM

Continuity

Connector

Terminal

Connector

Terminal

F50

1

F8

49

Existed

2

53

P0171 FUEL INJECTION SYSTEM FUNCTION

EC-217

< DTC/CIRCUIT DIAGNOSIS >

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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.

Check fuel pressure. Refer to 

EC-478, "Inspection"

.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

 DETECT MALFUNCTIONING PART

Check fuel hoses and fuel tubes for clogging.

Is the inspection result normal?

YES

>> Replace “fuel filter and fuel pump assembly”. Refer to 

FL-5, "Exploded View"

.

NO

>> Repair or replace

6.

CHECK MASS AIR FLOW SENSOR

With CONSULT

1.

Install all removed parts.

2.

Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT.

3.

For specification, refer to 

EC-482, "Mass Air Flow Sensor"

.

With GST

1.

Install all removed parts.

2.

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

3.

For specification, refer to 

EC-482, "Mass Air Flow Sensor"

.

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-147, "DTC Logic"

.

7.

CHECK FUNCTION OF FUEL INJECTOR

With CONSULT

1.

Start engine.

2.

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

3.

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

Without CONSULT

1.

Let engine idle.

A/F sensor 1

Ground

Continuity

Connector

Terminal

F50

1

Ground

Not existed

2

ECM

Ground

Continuity

Connector

Terminal

F8

49

Ground

Not existed

53