Infiniti FX35, FX50 (S51). Manual - part 797

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-729

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Diagnosis Procedure

INFOID:0000000005237218

OVERALL SEQUENCE

JMBIA1468GB

EC-730

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TROUBLE DIAGNOSIS - SPECIFICATION VALUE

DETAILED PROCEDURE

1.

CHECK “A/F ALPHA-B1” AND “A/F ALPHA-B2”

 With CONSULT-III

1.

Start engine.

2.

Confirm that the testing conditions are met. Refer to 

EC-728, "Component Function Check"

.

3.

Select “A/F ALPHA-B1” and “A/F ALPHA-B2” in “SPEC” of “DATA MONITOR” mode, and check that each
indication is within the SP value.

JMBIA0056GB

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-731

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NOTE:
Check “A/F ALPHA-B1” and “A/F ALPHA-B2” for approximately 1 minute because they may fluctuate. It is
NG if the indication is out of the SP value even a little.

Is the measurement value within the SP value?

YES

>> GO TO 17.

NO-1

>> Less than the SP value: GO TO 2.

NO-2

>> More than the SP value: GO TO 3.

2.

CHECK “B/FUEL SCHDL”

Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and check that the indication is within the SP
value.

Is the measurement value within the SP value?

YES

>> GO TO 4.

NO

>> More than the SP value: GO TO 19.

3.

CHECK “B/FUEL SCHDL”

Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and check that the indication is within the SP
value.

Is the measurement value within the SP value?

YES

>> GO TO 6.

NO-1

>> More than the SP value: GO TO 6.

NO-2

>> Less than the SP value: GO TO 25.

4.

CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”

1.

Stop the engine.

2.

Disconnect PCV hose, and then plug it.

3.

Start engine.

4.

Select “A/F ALPHA-B1” and “A/F ALPHA-B2” in “SPEC” of “DATA MONITOR” mode, and check that each
indication is within the SP value.

Is the measurement value within the SP value?

YES

>> GO TO 5.

NO

>> GO TO 6.

5.

CHANGE ENGINE OIL

1.

Stop the engine.

2.

Change engine oil.
NOTE:
This symptom may occur when a large amount of gasoline is mixed with engine oil because of driving
conditions (such as when engine oil temperature does not rise enough since a journey distance is too
short during winter). The symptom will not be detected after changing engine oil or changing driving con-
ditions.

>> INSPECTION END

6.

CHECK FUEL PRESSURE

Check fuel pressure. (Refer to 

EC-1236, "Inspection"

.)

Is the inspection result normal?

YES

>> GO TO 9.

NO-1

>> Fuel pressure is too high: Replace “fuel filter and fuel pump assembly” and then GO TO 8.

NO-2

>> Fuel pressure is too low: GO TO 7.

7.

DETECT MALFUNCTIONING PART

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

YES

>> Replace “fuel filter and fuel pump assembly” and then GO TO 8.

NO

>> Repair or replace and then GO TO 8.

8.

CHECK “A/F ALPHA-B1” AND “A/F ALPHA-B2”

EC-732

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TROUBLE DIAGNOSIS - SPECIFICATION VALUE

1.

Start engine.

2.

Select “A/F ALPHA-B1” and “A/F ALPHA-B2” in “SPEC” of “DATA MONITOR” mode, and check that each
indication is within the SP value.

Is the measurement value within the SP value?

YES

>> INSPECTION END

NO

>> GO TO 9.

9.

PERFORM POWER BALANCE TEST

1.

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

2.

Check that each cylinder produces a momentary engine speed drop.

Is the inspection result normal?

YES

>> GO TO 12.

NO

>> GO TO 10.

10.

DETECT MALFUNCTIONING PART

Check the following below.
• Ignition coil and its circuit (Refer to 

EC-1114, "Component Function Check"

.)

• Fuel injector and its circuit (Refer to 

EC-1103, "Component Function Check"

.)

• Intake air leakage
• Low compression pressure (Refer to 

EM-173, "Inspection"

.)

Is the inspection result normal?

YES

>> Replace fuel injector and then GO TO 11.

NO

>> Repair or replace malfunctioning part and then GO TO 11.

11.

CHECK “A/F ALPHA-B1” AND “A/F ALPHA-B2”

1.

Start engine.

2.

Select “A/F ALPHA-B1” and “A/F ALPHA-B2” in “SPEC” of “DATA MONITOR” mode, and check that each
indication is within the SP value.

Is the measurement value within the SP value?

YES

>> INSPECTION END

NO

>> GO TO 12.

12.

CHECK A/F SENSOR 1 FUNCTION

Perform all DTC CONFIRMATION PROCEDURE related with A/F sensor 1.
• For DTC P0130, P0150, refer to 

EC-805, "DTC Logic"

.

• For DTC P0131, P0151, refer to 

EC-809, "DTC Logic"

.

• For DTC P0132, P0152, refer to 

EC-812, "DTC Logic"

.

• For DTC P0133, P0153, refer to 

EC-815, "DTC Logic"

.

• For DTC P2A00, P2A03, refer to 

EC-1088, "DTC Logic"

.

Are any DTCs detected?

YES

>> GO TO 13.

NO

>> GO TO 15.

13.

CHECK A/F SENSOR 1 CIRCUIT

Perform Diagnosis Procedure according to corresponding DTC.

>> GO TO 14.

14.

CHECK “A/F ALPHA-B1” AND “A/F ALPHA-B2”

1.

Start engine.

2.

Select “A/F ALPHA-B1” and “A/F ALPHA-B2” in “SPEC” of “DATA MONITOR” mode, and check that each
indication is within the SP value.

Is the measurement value within the SP value?

YES

>> INSPECTION END

NO

>> GO TO 15.

15.

DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR

1.

Stop the engine.