Nissan Qashqai J11. Manual - part 313

P014C, P014D A/F SENSOR 1

ECM-229

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10.

REPLACE AIR FUEL RATIO (A/F) SENSOR 1

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

EM-153, "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-230

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P0171 FUEL INJECTION SYSTEM FUNCTION

P0171 FUEL INJECTION SYSTEM FUNCTION

DTC Description

INFOID:0000000010702938

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 A/F sensor 1. The ECM calculatesthe
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).

POSSIBLE CAUSE

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

FAIL-SAFE

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.

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.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

P0171

FUEL SYS-LEAN-B1
(System too lean bank 1)

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

is too lean.)

Engine operating condition in fail-safe mode

Fail safe mode

Vehicle behavior

Traveling con-
trol mode

Accelerator an-
gle variation 
control

ECM controls the accelerator pedal depression speed to make it slower than actual speed. This 
causes a drop in accelerating performance and encourages the driver to repair malfunction.
NOTE:
ECM does not control the accelerator pedal releasing speed.

Combustion 
control mode

Stratified charge 
combustion 
control at start-
ing

No stratified charge combustion at starting (cold start).

Idle speed con-
trol

Stops feedback control of idle speed and controls with specified speed.

Recovery speed 
control at decel-
erating

Stops recovery speed control by the fuel cut at decelerating and controls with specified speed.

Idle neutral con-
trol

Stops idle neutral control.

P0171 FUEL INJECTION SYSTEM FUNCTION

ECM-231

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>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE-I

1.

Clear the mixture ratio self-learning value. Refer to 

ECM-131, "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.

Does engine start?

YES

>> Proceed to 

ECM-231, "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

>> Proceed to 

ECM-231, "Diagnosis Procedure"

.

NO

>> GO TO 5.

5.

PERFORM DTC CONFIRMATION PROCEDURE-III

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.

3.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Proceed to 

ECM-231, "Diagnosis Procedure"

.

NO-1

>> To check malfunction symptom before repair: Refer to 

GI-41, "Intermittent Incident"

.

NO-2

>> Confirmation after repair: INSPECTION END

Diagnosis Procedure

INFOID:0000000010702939

1.

CHECK EXHAUST GAS LEAKAGE

1.

Start engine and run it at idle.

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).

ECM-232

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P0171 FUEL INJECTION SYSTEM FUNCTION

2.

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

Is exhaust gas leakage detected?

YES

>> Repair or replace malfunctioning part.

NO

>> GO TO 2.

2.

CHECK FOR INTAKE AIR LEAKAGE

1.

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

2.

Check PCV hose connection.

Is intake air leakage detected?

YES

>> Repair or replace malfunctioning part.

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 and ground, or ECM harness connector
and ground.

6.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace malfunctioning part.

4.

CHECK FUEL PRESSURE

PBIB1216E

+

−

Continuity

A/F sensor 1

ECM

Connector

Terminal

Connector

Terminal

F74

1

F16

64

Existed

2

72

+

Ground

Continuity

A/F sensor 1

Connector

Terminal

F74

1

Ground

Not existed

2

+

Ground

Continuity

ECM

Connector

Terminal

F16

64

Ground

Not existed

72