Infiniti QX56 (JA60). Manual - part 340

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< BASIC INSPECTION >

[VK56DE]

DIAGNOSIS AND REPAIR WORKFLOW

There are many operating conditions that lead to the malfunction of

engine components. A good grasp of such conditions can make trou-

bleshooting faster and more accurate.

In general, each customer feels differently about a incident. It is

important to fully understand the symptoms or conditions for a cus-

tomer complaint.

Utilize a diagnostic worksheet like the one on the next page in order

to organize all the information for troubleshooting.

Some conditions may cause the MIL to come on steady or blink and

DTC to be detected. Examples:

• Vehicle ran out of fuel, which caused the engine to misfire.

• Fuel filler cap was left off or incorrectly screwed on, allowing fuel to

evaporate into the atmosphere.

Worksheet Sample

SEF907L

MTBL0017

INSPECTION AND ADJUSTMENT

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INSPECTION AND ADJUSTMENT

Basic Inspection

INFOID:0000000005149055

1.

INSPECTION START

1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for

scheduled maintenance.

2. Open engine hood and check the following:

-

Harness connectors for improper connections

-

Wiring harness for improper connections, pinches and cut

-

Vacuum hoses for splits, kinks and improper connections

-

Hoses and ducts for leaks

-

Air cleaner clogging

-

Gasket

3. Confirm that electrical or mechanical loads are not applied.

-

Headlamp switch is OFF.

-

Air conditioner switch is OFF.

-

Rear window defogger switch is OFF.

-

Steering wheel is in the straight-ahead position, etc.

4. Start engine and warm it up until engine coolant temperature

indicator points the middle of gauge.

Ensure engine stays below 1,000 rpm.

5. Run engine at about 2,000 rpm for about 2 minutes under no

load.

6. Make sure that no DTC is displayed with CONSULT-III or GST.
OK or NG

OK

>> GO TO 3.

NG

>> GO TO 2.

2.

REPAIR OR REPLACE

Repair or replace components as necessary according to corresponding Diagnostic Procedure.

>> GO TO 3.

3.

CHECK TARGET IDLE SPEED

 With CONSULT-III

1. Run engine at about 2,000 rpm for about 2 minutes under no load.

SEF983U

SEF976U

SEF977U

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< BASIC INSPECTION >

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INSPECTION AND ADJUSTMENT

2. Rev engine (2,000 to 3,000 rpm) two or three times under no

load, then run engine at idle speed for about 1 minute.

3. Read idle speed in “DATA MONITOR” mode with CONSULT-III. Refer to 

EC-17, "Idle Speed and Ignition

Timing Check"

 .

 Without CONSULT-III

1. Run engine at about 2,000 rpm for about 2 minutes under no load.

2. Rev engine (2,000 to 3,000 rpm) two or three times under no load, then run engine at idle speed for about

1 minute.

3. Check idle speed.

Refer to 

EC-17, "Idle Speed and Ignition Timing Check"

 .

OK or NG

OK

>> GO TO 10.

NG

>> GO TO 4.

4.

PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING

1. Stop engine.

2. Perform 

EC-18, "Accelerator Pedal Released Position Learning"

 .

>> GO TO 5.

5.

PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

Perform 

EC-18, "Throttle Valve Closed Position Learning"

 .

>> GO TO 6.

6.

PERFORM IDLE AIR VOLUME LEARNING

Refer to 

EC-18, "Idle Air Volume Learning"

 .

Is Idle Air Volume Learning carried out successfully?
Yes or No

Yes

>> GO TO 7.

No

>> 1. Follow the instruction of Idle Air Volume Learning.

2. GO TO 4.

7.

CHECK TARGET IDLE SPEED AGAIN

 With CONSULT-III

1. Start engine and warm it up to normal operating temperature.

2. Read idle speed in “DATA MONITOR” mode with CONSULT-III.

Refer to 

EC-17, "Idle Speed and Ignition Timing Check"

 .

 Without CONSULT-III

PBIA8513J

650 

± 50 rpm (in P or N position)

650 

± 50 rpm (in P or N position)

650 

± 50 rpm (in P or N position)

INSPECTION AND ADJUSTMENT

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1. Start engine and warm it up to normal operating temperature.

2. Check idle speed.

Refer to 

EC-17, "Idle Speed and Ignition Timing Check"

 .

OK or NG

OK

>> GO TO 10.

NG

>> GO TO 8.

8.

DETECT MALFUNCTIONING PART

Check the following.

• Check camshaft position sensor (PHASE) and circuit. Refer to 

EC-205

 .

• Check crankshaft position sensor (POS) and circuit. Refer to 

EC-201

 .

OK or NG

OK

>> GO TO 9.

NG

>> 1. Repair or replace.

2. GO TO 4.

9.

CHECK ECM FUNCTION 

1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but

this is a rare case.)

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

SEC-14, "System Diagram"

.

>> GO TO 4.

10.

CHECK IGNITION TIMING

1. Run engine at idle.

2. Check ignition timing with a timing light.

Refer to 

EC-17, "Idle Speed and Ignition Timing Check"

 .

OK or NG

OK

>> GO TO 19.

NG

>> GO TO 11.

11.

PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING

1. Stop engine.

2. Perform 

EC-18, "Accelerator Pedal Released Position Learning"

 .

>> GO TO 12.

12.

PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

Perform 

EC-18, "Throttle Valve Closed Position Learning"

 .

>> GO TO 13.

13.

PERFORM IDLE AIR VOLUME LEARNING

Refer to 

EC-18, "Idle Air Volume Learning"

 .

Is Idle Air Volume Learning carried out successfully?
Yes or No

Yes

>> GO TO 14.

No

>> 1. Follow the instruction of Idle Air Volume Learning.

650 

± 50 rpm (in P or N position)

15 

± 5° BTDC (in P or N position)

BBIA0379E