Nissan X-Trail 32. Manual - part 860

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-569

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

8.

CHECK “A/F ALPHA-B1”

1.

Start engine.

2.

Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the 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.

Make sure 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.
1.

Ignition coil and its circuit (Refer to 

EC-785, "Component Function Check"

.)

2.

Fuel injector and its circuit (Refer to 

EC-779, "Component Function Check"

.)

3.

Intake air leakage

4.

Low compression pressure (Refer to 

EM-162, "Inspection"

.)

Is the inspection result normal?

YES

>> Replace fuel injector, refer to 

EM-184, "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”

1.

Start engine.

2.

Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the 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, refer to 

EC-618, "DTC Description"

.

• For DTC P0131, refer to 

EC-622, "DTC Description"

.

• For DTC P0132, refer to 

EC-625, "DTC Description"

.

• For DTC P014C, P014D, refer to 

EC-647, "DTC Description"

.

Is any DTC 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”

1.

Start engine.

2.

Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the 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

EC-570

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

1.

Stop the engine.

2.

Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.

>> GO TO 16.

16.

CHECK “A/F ALPHA-B1”

1.

Start engine.

2.

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

Is the measurement value within the SP value?

YES

>> INSPECTION END

NO

>> Detect malfunctioning part according to 

EC-796, "Symptom Table"

.

17.

CHECK “B/FUEL SCHDL”

Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
Is the measurement value within the SP value?

YES

>> INSPECTION END

NO-1

>> More than the SP value: GO TO 18.

NO-2

>> Less than the SP value: GO TO 25.

18.

DETECT MALFUNCTIONING PART

1.

Check for the cause of large engine friction. Refer to the following.

-

Engine oil level is too high

-

Engine oil viscosity

-

Belt tension of power steering, alternator, A/C compressor, etc. is excessive

-

Noise from engine

-

Noise from transmission, etc.

2.

Check for the cause of insufficient combustion. Refer to the following.

-

Valve clearance malfunction

-

Intake valve timing control function malfunction

-

Camshaft sprocket installation malfunction, etc.

>> Repair or replace malfunctioning part, and then GO TO 30.

19.

CHECK INTAKE SYSTEM

Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
• Crushed air ducts
• Malfunctioning seal of air cleaner element
• Uneven dirt of air cleaner element
• Improper specification of intake air system

Is the inspection result normal?

YES

>> GO TO 21.

NO

>> Repair or replace malfunctioning part, and then GO TO 20.

20.

CHECK “A/F ALPHA-B1”, AND “B/FUEL SCHDL”

Select “A/F ALPHA-B1” and “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.

Is the measurement value within the SP value?

YES

>> INSPECTION END

NO

>> “B/FUEL SCHDL” is more, “A/F ALPHA-B1” is less than the SP value: GO TO 21.

21.

DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR

1.

Stop the engine.

2.

Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.

>> GO TO 22.

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-571

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

22.

CHECK “A/F ALPHA-B1”

1.

Start engine.

2.

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

Is the measurement value within the SP value?

YES

>> Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to 

EC-605, "DTC

Description"

. Then GO TO 29.

NO

>> GO TO 23.

23.

CHECK “MASS AIR FLOW SENSOR (HZ)”

Select “MASS AIR FLOW SENSOR (Hz)” in “SPEC” of “DATA MONITOR” mode, and make sure that the indi-
cation is within the SP value.
Is the measurement value within the SP value?

YES

>> GO TO 24.

NO

>> More than the SP value: Replace mass air flow sensor, refer to 

EM-174, "Exploded View"

, and

then GO TO 29.

24.

REPLACE ECM

Replace ECM. Refer to 

EC-806, "Removal and Installation"

.

>> GO TO 29.

25.

CHECK INTAKE SYSTEM

Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
• Crushed air ducts
• Malfunctioning seal of air cleaner element
• Uneven dirt of air cleaner element
• Improper specification of intake air system

Is the inspection result normal?

YES

>> GO TO 27.

NO

>> Repair or replace malfunctioning part, and then GO TO 26.

26.

CHECK “B/FUEL SCHDL”

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

Is the measurement value within the SP value?

YES

>> INSPECTION END

NO

>> Less than the SP value: GO TO 27.

27.

CHECK “MASS AIR FLOW SENSOR (HZ)”

Select “MASS AIR FLOW SENSOR (Hz)” in “SPEC” of “DATA MONITOR” mode, and make sure that the indi-
cation is within the SP value.

Is the measurement value within the SP value?

YES

>> GO TO 28.

NO

>> Less than the SP value: Replace mass air flow sensor, refer to 

EM-174, "Exploded View"

, and

then GO TO 30.

28.

CHECK INTAKE SYSTEM

Check for the cause of air leak after the mass air flow sensor. Refer to the following.
• Disconnection, looseness, and cracks in air duct
• Looseness of oil filler cap
• Disconnection of oil level gauge
• Open stuck, breakage, hose disconnection, or cracks of PCV valve
• Disconnection or cracks of EVAP purge hose, open stuck of EVAP canister purge volume control solenoid

valve

• Malfunctioning seal of rocker cover gasket
• Disconnection, looseness, or cracks of hoses, such as vacuum hose, connecting to intake air system parts

EC-572

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

• Malfunctioning seal of intake air system, etc.

>> GO TO 30.

29.

CHECK “A/F ALPHA-B1” AND “B/FUEL SCHDL”

Select “A/F ALPHA-B1” and “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the
indication is within the SP value. 

Is the measurement value within the SP value?

YES

>> INSPECTION END

NO

>> Detect malfunctioning part according to 

EC-796, "Symptom Table"

.

30.

CHECK “B/FUEL SCHDL”

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

Is the measurement value within the SP value?

YES

>> INSPECTION END

NO

>> Detect malfunctioning part according to 

EC-796, "Symptom Table"

.