Nissan Quest E52. Manual - part 530

EC-330

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0507 ISC SYSTEM

NO

>> Repair or replace malfunctioning part.

2.

CHECK INTAKE AIR LEAKAGE

1.

Start engine and let it idle.

2.

Listen for an intake air leakage after the mass air flow sensor.

Is intake air leakage detected?

YES

>> Discover air leakage location and repair.

NO

>> Replace ECM. Refer to 

EC-460, "Removal and Installation"

.

P050A, P050E COLD START CONTROL

EC-331

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

P050A, P050E COLD START CONTROL

Description

INFOID:0000000009651165

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

INFOID:0000000009651166

DTC DETECTION LOGIC

NOTE:
If DTC P050A, P050E is displayed with other DTC, first perform the trouble diagnosis for other DTC.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
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 more than 11 V at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE-I

With CONSULT

1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Select “DATA MONITOR” mode with CONSULT.

4.

Check the indication of “COOLAN TEMP/S”.

With GST

Follow the procedure “With CONSULT” above.

Is the value of “COOLAN TEMP/S” between 4

°

C (39

°

F) and 36

°

C (97

°

F)?

YES

>> GO TO 3.

NO-1 [If it is below 4

°

C (39

°

F)]>>Warm up the engine until the value of “COOLAN TEMP/S” reaches 4

°

C

(39

°

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

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 4

°

C (39

°

F) and 40

°

C

(104

°

F) for more than 15 seconds.

3.

Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT” above.
Is 1st trip DTC detected?

YES

>> Proceed to 

EC-332, "Diagnosis Procedure"

.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P050A

Cold start idle air control system 
performance

ECM does not control engine idle speed properly 
when engine is started with pre-warming up con-
dition.

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

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.

EC-332

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P050A, P050E COLD START CONTROL

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009651167

1.

PERFORM IDLE AIR VOLUME LEARNING

Perform 

EC-137, "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-241, "DTC Logic"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Proceed to 

EC-242, "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-331, "DTC Logic"

.

Is the 1st trip DTC P050A, P050E displayed again?

YES

>> Replace ECM. Refer to 

EC-460, "Removal and Installation"

.

NO

>> INSPECTION END

P0603 ECM POWER SUPPLY

EC-333

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

P0603 ECM POWER SUPPLY

DTC Logic

INFOID:0000000009651168

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next test.
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.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON and wait at least 10 second.

2.

Turn ignition switch OFF and wait at least 5 minutes.

3.

Turn ignition switch ON, wait at least 10 seconds.

4.

Repeat steps 2 and 3 for five times.

5.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-333, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009651169

1.

CHECK ECM POWER SUPPLY

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check the voltage between ECM harness connector terminals.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Perform the trouble diagnosis for power supply circuit.

2.

CHECK INTERMITTENT INCIDENT

Check intermittent incident. Refer to 

GI-42, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace error-detected parts.

3.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0603

ECM power supply cir-
cuit

ECM back up RAM system does not function 
properly.

• Harness or connectors

[ECM power supply (back up) circuit is 
open or shorted.]

• ECM

ECM

Voltage

+

–

Connector

Terminal

Connector

Terminal

F7

26

E16

128

Battery voltage