Nissan Rogue. Manual - part 500

EC-268

< DTC/CIRCUIT DIAGNOSIS >

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P0172 FUEL INJECTION SYSTEM FUNCTION

P0172 FUEL INJECTION SYSTEM FUNCTION

DTC Description

INFOID:0000000011277998

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 rich.), the

ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).

POSSIBLE CAUSE

• A/F sensor 1

• Fuel injector

• Exhaust gas leaks

• Incorrect fuel pressure

• Mass air flow sensor

FAIL-SAFE

Traveling control mode (Accelerator angle variation control)

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE-1

1. Clear the mixture ratio self-learning value. Refer to 

EC-146, "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 does not start the

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

YES

>> Proceed to 

EC-269, "Diagnosis Procedure"

.

NO

>> Check exhaust and intake air leak visually.

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

P0172

FUEL SYS-RICH-B1
(System too rich bank 1)

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

is too rich.)

P0172 FUEL INJECTION SYSTEM FUNCTION

EC-269

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4.

PERFORM DTC CONFIRMATION PROCEDURE-2

1. Start engine and let it idle for at least 5 minutes.

2. Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Proceed to 

EC-269, "Diagnosis Procedure"

.

NO

>> GO TO 5.

5.

PERFORM DTC CONFIRMATION PROCEDURE-3

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

>> Proceed to 

EC-269, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000011277999

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 error-detected parts.

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 error-detected parts.

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.

VHCL SPEED SE

50 - 120 km/h (31 - 75 MPH)

PBIB1216E

EC-270

< DTC/CIRCUIT DIAGNOSIS >

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P0172 FUEL INJECTION SYSTEM FUNCTION

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 power.
Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace error-detected parts.

4.

CHECK FUEL PRESSURE

Check fuel pressure. Refer to 

EC-147, "Work Procedure"

.

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. Refer to 

EM-45, "Exploded View"

.

Is the inspection result normal?

YES

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

FL-5, "Removal and Installation"

.

NO

>> Repair or replace error-detected parts.

6.

CHECK MASS AIR FLOW SENSOR

With CONSULT

1. Install all removed parts.

2. Start engine and warm it up to normal operating temperature.

3. Check “MASS AIR FLOW SENSOR (Hz)” in “DATA MONITOR” mode of “ENGINE” using CONSULT.

*: Check for linear frequency rise in response to engine being increased to about 4,000 rpm.

+

−

Continuity

A/F sensor 1

ECM

Connector

Terminal

Connector

Terminal

F18

1

F51

41

Existed

2

45

+

−

Continuity

A/F sensor 1

Connector

Terminal

F18

1

Ground

Not existed

2

+

−

Continuity

ECM

Connector

Terminal

F51

41

Ground

Not existed

45

Monitor item

Condition

Value

MASS AIR 

FLOW SENSOR 

(Hz)

Ignition switch ON (Engine stopped.)

Approx. 3500 Hz

Idle (Engine is warmed-up to normal operating temper-
ature.)

3500- 4100 Hz

2,500 rpm (Engine is warmed-up to normal operating 
temperature.)

5000k - 5600 Hz

Idle to about 4,000 rpm

3500 - 4100 Hz to Approx. 6300 Hz*

P0172 FUEL INJECTION SYSTEM FUNCTION

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Without CONSULT

1. Install all removed parts.

2. Start engine and warm it up to normal operating temperature.

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

*: Check for linear frequency rise in response to engine being increased to about 4,000 rpm.

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-201, "DTC Description"

.

7.

CHECK FUNCTION OF FUEL INJECTOR

With CONSULT

1. Start engine.

2. Perform “POWER BALANCE” in “ACTIVE TEST” mode of “ENGINE” using CONSULT.

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

Without CONSULT

1. Let engine idle.

2. Listen to each fuel injector operating sound.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Perform trouble diagnosis for “FUEL INJECTOR”, refer

to 

EC-467, "Component Function Check"

.

8.

CHECK FUEL INJECTOR

1. Turn ignition switch OFF.

2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.

3. Disconnect all fuel injector harness connectors.

4. Remove fuel tube assembly. Refer to 

EM-45, "Removal and Installation"

.

Keep fuel hose and all fuel injectors connected to fuel tube.

5. Disconnect all ignition coil harness connectors.

6. Prepare pans or saucers under each fuel injector.

ECM

Condition

Value

Connector

+

−

Terminal

F51

35

34

Ignition switch ON (Engine stopped.)

Approx. 3500 Hz

Idle (Engine is warmed-up to normal operating temper-
ature.)

3500- 4100 Hz

2,500 rpm (Engine is warmed-up to normal operating 
temperature.)

5000k - 5600 Hz

Idle to about 4,000 rpm

3500 - 4100 Hz to Approx. 6300 Hz*

Ignition switch ON (Engine stopped.)

Approx. 3500 Hz

Clicking noise should be heard.

PBIB3332E