Nissan Pathfinder. Manual - part 465

EC-166

< DTC/CIRCUIT DIAGNOSIS >

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TROUBLE DIAGNOSIS - SPECIFICATION VALUE

Diagnosis Procedure

INFOID:0000000009178095

OVERALL SEQUENCE

JMBIA1468GB

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-167

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DETAILED PROCEDURE

1.

CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”

With CONSULT

1. Start engine.

2. Confirm that the testing conditions are met. Refer to 

EC-165, "Component Function Check"

.

3. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “SPEC” of “DATA MONITOR” mode, and check that each

indication is within the SP value.

PBIB3214E

EC-168

< DTC/CIRCUIT DIAGNOSIS >

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TROUBLE DIAGNOSIS - SPECIFICATION VALUE

NOTE:

Check “A/F ALPHA-B1”, “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”, “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-151, "Work Procedure"

.)

Is the inspection result normal?

YES

>> GO TO 9.

NO-1 >> Fuel pressure is too high: Replace “fuel filter and fuel pump assembly”, refer to 

FL-6, "Removal

and Installation"

, 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”, refer to 

FL-6, "Removal and Installation"

, and then

GO TO 8.

NO

>> Repair or replace malfunctioning part and then GO TO 8.

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-169

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8.

CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”

1. Start engine.

2. Select “A/F ALPHA-B1”, “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 the 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-437, "Component Function Check"

.)

• Fuel injector and its circuit (Refer to 

EC-430, "Component Function Check"

.)

• Intake air leakage

• Low compression pressure (Refer to 

EM-22, "On-Vehicle Service"

.)

Is the inspection result normal?

YES

>> Replace fuel injector, refer to 

EM-47, "Removal and Installation"

, and then GO TO 11.

NO

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

11.

CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”

1. Start engine.

2. Select “A/F ALPHA-B1”, “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-217, "DTC Logic"

.

• For DTC P0131, P0151, refer to 

EC-221, "DTC Logic"

.

• For DTC P0132, P0152, refer to 

EC-224, "DTC Logic"

.

• For DTC P014C, P014D, P014E, P014F, P015A, P015B, P015C, P015D, refer to 

EC-246, "DTC Logic"

.

• For DTC P2096, P2097, P2098, P2099, refer to 

EC-396, "DTC Logic"

.

Are any DTCs detected?

YES

>> GO TO 15.

NO

>> GO TO 13.

13.

CHECK A/F SENSOR 1 CIRCUIT

Perform Diagnostic Procedure according to corresponding DTC.

>> GO TO 14.

14.

CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”

1. Start engine.

2. Select “A/F ALPHA-B1”, “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.