Infiniti QX56 (Z62). Manual - part 596

EC-362

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

P050E COLD START CONTROL

P050E COLD START CONTROL

Description

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ECM controls ignition timing and engine idle speed when engine is started with pre-warming up condition.
This control promotes the activation of three way catalyst by heating the catalyst and reduces emissions.

DTC Logic

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DTC DETECTION LOGIC

NOTE:
If DTC P050E is displayed with other DTC, first perform the trouble diagnosis for other DTC.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE-I

WITH CONSULT-III

1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Select “DATA MONITOR” mode with CONSULT-III.

4.

Check the indication of “COOLAN TEMP/S”.

WITH GST

Follow the procedure “With CONSULT-III” above.
Is the value of “COOLAN TEMP/S” between 5

°

C (41

°

F) and 36

°

C (97

°

F)?

YES

>> GO TO 3.

NO-1 [If it is below 5

°

C (41

°

F)]>>Warm up the engine until the value of “COOLAN TEMP/S” reaches 5

°

C

(41

°

F) or more. Retry from step 1.

NO-2 [If it is above 36

°

C (97

°

F)]>>Cool engine down to less than 36

°

C (97

°

F). Retry from step 1.

3.

PERFORM DTC CONFIRMATION PROCEDURE-II

WITH CONSULT-III

1.

Set the select lever in N range.

2.

Start the engine and warm up in idle with the value of “COOLAN TEMP/S” between 5

°

C (41

°

F) and 40

°

C

(104

°

F) for more than 15 seconds.

3.

Check 1st trip DTC.

WITH GST

Follow the procedure “With CONSULT-III” above.

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-362, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006288338

1.

PERFORM IDLE AIR VOLUME LEARNING

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P050E

Cold start engine exhaust temper-
ature too low

The temperature of the catalyst inlet does not 
rise to the proper temperature when the engine 
is started with pre-warming up condition.

• Lack of intake air volume
• Fuel injection system
• ECM

P050E COLD START CONTROL

EC-363

< DTC/CIRCUIT DIAGNOSIS >

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Perform 

EC-148, "Work Procedure"

.

Is Idle Air Volume Learning carried out successfully?

YES

>> GO TO 2.

NO

>> Follow the instruction of Idle Air Volume Learning.

2.

CHECK INTAKE SYSTEM

Check for the cause of intake air volume lacking. Refer to the following.
• Crushed intake air passage
• Intake air passage clogging
• Clogging of throttle body

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace malfunctioning part

3.

CHECK FUEL INJECTION SYSTEM FUNCTION

Perform DTC Confirmation Procedure for DTC P0171, P0174. Refer to 

EC-263, "DTC Logic"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Proceed to 

EC-264, "Diagnosis Procedure"

 for DTC P0171, P0174.

4.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

2.

Erase DTC.

3.

Perform DTC Confirmation Procedure.
See 

EC-362, "DTC Logic"

.

Is the 1st trip DTC P050E displayed again?

YES

>> GO TO 5.

NO

>> INSPECTION END

5.

REPLACE ECM

Replace ECM. Refer to 

EC-535, "Removal and Installation"

. 

>> INSPECTION END

EC-364

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

P0524 ENGINE OIL PRESSURE

P0524 ENGINE OIL PRESSURE

DTC Logic

INFOID:0000000006288342

DTC DETECTION LOGIC

NOTE:
If DTC P0524 is displayed with DTC P0075 or P0081, perform trouble diagnosis for DTC P0075 or P0081
first. Refer to 

EC-193, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING-I

1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is between 10 V and 16 V at
idle.

>> GO TO 2.

2.

PRECONDITIONING-II

Check oil level and oil pressure. Refer to 

LU-7, "Inspection"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Proceed to 

LU-7, "Inspection"

.

3.

PERFORM DTC CONFIRMATION PROCEDURE

 WITH CONSULT-III

1.

Select “DATA MONITOR” mode with CONSULT-III.

2.

Maintain the following conditions for at least 20 consecutive seconds.

CAUTION:

Always drive at a safe speed.

3.

Check 1st trip DTC.

 WITH GST

Follow the procedure “With CONSULT-III” above.

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-365, "Diagnosis Procedure"

DTC No.

Trouble diagnosis name

(Trouble diagnosis content)

Detecting condition

Possible cause

P0524

ENGINE OIL PRESSURE
(Engine oil pressure too low)

Engine oil pressure is low because 
there is a gap between angle of target 
and phase-control angle.

• Engine oil pressure or level too low
• Crankshaft position sensor
• Camshaft position sensor
• Intake valve timing control solenoid valve
• Accumulation of debris to the signal pick-up por-

tion of the camshaft

• Timing chain installation
• Foreign matter caught in the oil groove for intake 

valve timing control

ENG SPEED

More than 1,700 rpm

COOLAN TEMP/S

More than 70

°

C (158

°

F)

Selector lever

1st or 2nd position

Driving location uphill

Driving vehicle uphill
(Increased engine load will help maintain the driving 
conditions required for this test.)

P0524 ENGINE OIL PRESSURE

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NO

>> INSPECTION END

Diagnosis Procedure

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1.

CHECK OIL PRESSURE WARNING LAMP

1.

Start engine.

2.

Check oil pressure warning lamp and confirm it is not illumi-
nated.

Is oil pressure warning lamp illuminated?

YES

>> Proceed to 

LU-7, "Inspection"

.

NO

>> GO TO 2.

2.

CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE

Refer to 

EC-179, "Component Inspection (Intake Valve Timing Control Solenoid Valve)"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Replace malfunctioning intake valve timing control solenoid valve.

3.

CHECK CRANKSHAFT POSITION SENSOR

Refer to 

EC-301, "Component Inspection (Crankshaft Position Sensor)"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace crankshaft position sensor.

4.

CHECK CAMSHAFT POSITION SENSOR

Refer to 

EC-306, "Component Inspection (Camshaft Position Sensor)"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace malfunctioning camshaft position sensor.

5.

CHECK CAMSHAFT SPROCKET (SIGNAL PLATE)

Check the following.
• Accumulation of debris to the signal plate of camshaft sprocket

(INT)

• Chipping signal plate of camshaft sprocket (INT)
Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Remove debris and clean the signal plate of camshaft

sprocket (INT) or replace camshaft sprocket (INT).
Refer to 

EM-61, "Exploded View"

.

6.

CHECK TIMING CHAIN INSTALLATION

Check service records for any recent repairs that may cause timing chain misaligned.

Are there any service records that may cause timing chain misaligned?

YES

>> Check timing chain installation. Refer to 

EM-61, "Exploded View"

.

NO

>> GO TO 7.

7.

CHECK LUBRICATION CIRCUIT

Perform “Inspection of Camshaft Sprocket (INT) Oil Groove”. Refer to 

LU-7, "Inspection"

.

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