Nissan Altima L32. Instruction — part 386

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-665

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COMPONENT DIAGNOSIS

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

Description

INFOID:0000000004349636

The specification (SP) value indicates the tolerance of the value that is displayed in “SPEC” of “DATA MONI-

TOR” mode of CONSULT-III during normal operation of the Engine Control System. When the value in “SPEC”

of “DATA MONITOR” mode is within the SP value, the Engine Control System is confirmed OK. When the

value in “SPEC” of “DATA MONITOR” mode is NOT within the SP value, the Engine Control System may have

one or more malfunctions.

The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the

MIL.

The SP value will be displayed for the following three items:

• B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board correc-

tion)

• A/F ALPHA-B1 (The mean value of air-fuel ratio feedback correction factor per cycle)

• MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)

Component Function Check

INFOID:0000000004349637

1.

START

Make sure that all of the following conditions are satisfied.

• Vehicle driven distance: More than 5,000 km (3,107 miles)
• Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm

2

, 14.25 - 15.12 psi)

• Atmospheric temperature: 20 - 30

°C (68 - 86°F)

• Engine coolant temperature: 75 - 95

°C (167 - 203°F)

• Transmission: Warmed-up

- CVT models: After the engine is warmed up to normal operating temperature, drive vehicle until “ATF TEMP

SEN” (CVT fluid temperature sensor signal) indicates more than 60

°C (140°F).

- M/T models: After the engine is warmed up to normal operating temperature, drive vehicle for 5 minutes.

• Electrical load: Not applied*

• Engine speed: Idle

*: Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight

ahead.

>> GO TO 2.

2.

PERFORM “SPEC” OF “DATA MONITOR” MODE

With CONSULT-III

NOTE:

Perform “SPEC” in “DATA MONITOR” mode in maximum scale display.

1. Perform

EC-560, "BASIC INSPECTION : Special Repair Requirement"

.

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

with CONSULT-III.

3. Make sure that monitor items are within the SP value.
Is the inspection result normal?

YES

>> END

NO

>> Go to

EC-666, "Diagnosis Procedure"

.

EC-666

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TROUBLE DIAGNOSIS - SPECIFICATION VALUE

Diagnosis Procedure

INFOID:0000000004349638

OVERALL SEQUENCE

PBIB2318E

TROUBLE DIAGNOSIS - SPECIFICATION VALUE

EC-667

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DETAILED PROCEDURE

1.

CHECK “A/F ALPHA-B1”

With CONSULT-III

1. Start engine.

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

EC-665, "Component Function Check"

.

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

within the SP value.

PBIB3213E

EC-668

< COMPONENT DIAGNOSIS >

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TROUBLE DIAGNOSIS - SPECIFICATION VALUE

NOTE:

Check “A/F ALPHA-B1” 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 make sure 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 make sure 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”

1. Stop the engine.

2. Disconnect PCV hose, and then plug it.

3. Start engine.

4. 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

>> 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-

dition.

>> INSPECTION END

6.

CHECK FUEL PRESSURE

Check fuel pressure. (Refer to

EC-1038, "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”