Nissan Frontier. Manual - part 629

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-1087

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR MEXICO]

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>> GO TO 8.

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 make sure that

each indication is within the SP value.

OK or NG

OK

>> INSPECTION END

NG

>> 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.
OK or NG

OK

>> GO TO 12.

NG

>> GO TO 10.

10.

DETECT MALFUNCTIONING PART

1. Check the following below.

-

Ignition coil and its circuit (Refer to 

EC-1354, "Component Description"

.)

-

Fuel injector and its circuit (Refer to 

EC-1346, "Component Description"

.)

-

Intake air leakage

-

Low compression pressure (Refer to 

EM-205, "Exploded View"

.)

2. If NG, repair or replace the malfunctioning part.

If OK, replace fuel injector. (It may be caused by leakage from fuel injector or clogging.)

>> 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 make sure that

each indication is within the SP value.

OK or NG

OK

>> INSPECTION END

NG

>> 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-1129, "DTC Confirmation Procedure"

.

• For DTC P0131, P0151, refer to 

EC-1133, "DTC Confirmation Procedure"

.

• For DTC P0132, P0152, refer to 

EC-1137, "DTC Confirmation Procedure"

.

• For DTC P0133, P0153, refer to 

EC-1141, "DTC Confirmation Procedure"

.

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

EC-1305, "DTC Confirmation Procedure"

.

OK or NG

OK

>> GO TO 15.

NG

>> 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 make sure that

each indication is within the SP value.

OK or NG

EC-1088

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR MEXICO]

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

OK

>> INSPECTION END

NG

>> GO TO 15.

15.

DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR

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”, “A/F ALPHA-B2”

1. Start engine.

2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that

each indication is within the SP value.

OK or NG

OK

>> INSPECTION END

NG

>> Detect malfunctioning part according to 

EC-1373, "Symptom Matrix Chart"

.

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.
OK or NG

OK

>> INSPECTION END

NG (More than the SP value)>>GO TO 18.

NG (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
OK or NG

OK

>> GO TO 21.

NG

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

20.

CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”

Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and

make sure that each indication is within the SP value.
OK or NG

OK

>> INSPECTION END

NG (“B/FUEL SCHDL” is more, “A/F ALPHA-B1”, “A/F ALPHA-B2” are less than the SP value)>>GO TO 21.

21.

DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR

1. Stop the engine.

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-1089

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR MEXICO]

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2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and

then reconnect it again.

>> GO TO 22.

22.

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 make sure that

each indication is within the SP value.

OK or NG

OK

>> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to 

EC-1110

.

2. GO TO 29.

NG

>> GO TO 23.

23.

CHECK “MAS A/F SE-B1”

Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the

SP value.
OK or NG

OK

>> GO TO 24.

NG (More than the SP value)>>Replace  mass  air flow sensor, and then GO TO 29. Refer to 

EM-141,

"Exploded View"

.

24.

REPLACE ECM

1. Replace ECM.

2. Perform initialization of NVIS(NATS) system and registration of all NVIS(NATS) ignition key IDs. Refer to

SEC-7, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Requirement"

.

3. Perform 

EC-1074, "VIN Registration"

.

4. Perform 

EC-1074, "Accelerator Pedal Released Position Learning"

.

5. Perform 

EC-1075, "Throttle Valve Closed Position Learning"

.

6. Perform 

EC-1075, "Idle Air Volume Learning"

.

>> 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 in air cleaner element

• Uneven dirt in air cleaner element

• Improper specification in intake air system
OK or NG

OK

>> GO TO 27.

NG

>> 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.
OK or NG

OK

>> INSPECTION END

NG (Less than the SP value)>>GO TO 27.

27.

CHECK “MAS A/F SE-B1”

Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the

SP value.
OK or NG

OK

>> GO TO 28.

NG (Less than the SP value)>>Replace  mass  air flow sensor, and then GO TO 30. Refer to 

EM-141,

"Exploded View"

.

EC-1090

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR MEXICO]

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

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 in EVAP purge hose, stick open canister purge volume control solenoid valve

• Malfunctioning seal in rocker cover gasket

• Disconnection, looseness, or cracks in hoses, such as a vacuum hose, connecting to intake air system parts

• Malfunctioning seal in intake air system, etc.

>> GO TO 30.

29.

CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”

Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and

make sure that  each indication is within the SP value. 
OK or NG

OK

>> INSPECTION END

NG

>> Detect malfunctioning part according to 

EC-1373, "Symptom Matrix Chart"

.

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.
OK or NG

OK

>> INSPECTION END

NG

>> Detect malfunctioning part according to 

EC-1373, "Symptom Matrix Chart"

.