Nissan Teana J32. Manual - part 425

EC-238

< COMPONENT DIAGNOSIS >

[VQ25DE, VQ35DE]

P0603 ECM POWER SUPPLY

P0603 ECM POWER SUPPLY

Description

INFOID:0000000003856699

Battery voltage is supplied to the ECM even when the ignition switch
is turned OFF for the ECM memory function of the DTC memory, the
air-fuel ratio feedback compensation value memory, the idle air vol-
ume learning value memory, etc.

DTC Logic

INFOID:0000000003856700

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON and wait at least 1 second.

2.

Start engine and let it idle for 1 second.

3.

Turn ignition switch OFF, wait at least 10 seconds, and then turn it ON.

4.

Repeat steps 2 and 3 for 4 times.

5.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-238, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000003856701

1.

CHECK ECM POWER SUPPLY

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check the voltage between ECM harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 2.

PBIA9222J

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

Ground

Voltage

Connector

Terminal

F8

77

Ground

Battery voltage

P0603 ECM POWER SUPPLY

EC-239

< COMPONENT DIAGNOSIS >

[VQ25DE, VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

2.

DETECT MALFUNCTIONING PART

Check the following.
• 15A fuse (No.50)
• IPDM E/R harness connector F12
• Harness for open or short between ECM and battery

>> Repair or replace harness or connectors.

3.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-35, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace harness or connectors.

4.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

2.

Erase DTC.

3.

Perform DTC CONFIRMATION PROCEDURE.
See 

EC-238, "DTC Logic"

.

Is the 1st trip DTC P0603 displayed again?

YES

>> GO TO 5.

NO

>> INSPECTION END

5.

REPLACE ECM

1.

Replace ECM.

2.

Go to 

EC-14, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Require-

ment"

.

>> INSPECTION END

EC-240

< COMPONENT DIAGNOSIS >

[VQ25DE, VQ35DE]

P0605 ECM

P0605 ECM

Description

INFOID:0000000003856702

The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The ECM controls the engine.

DTC Logic

INFOID:0000000003856703

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A

1.

Turn ignition switch ON.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-241, "Diagnosis Procedure"

.

NO

>> GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B

1.

Turn ignition switch ON and wait at least 1 second.

2.

Turn ignition switch OFF, wait at least 10 seconds, and then turn it ON.

3.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-241, "Diagnosis Procedure"

.

NO

>> GO TO 4.

4.

PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION C

1.

Turn ignition switch ON and wait at least 1 second.

2.

Turn ignition switch OFF, wait at least 10 seconds, and then turn it ON.

3.

Repeat step 2 for 32 times.

4.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-241, "Diagnosis Procedure"

.

NO

>> INSPECTION END

PBIA9222J

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0605

Engine control module

A)

ECM calculation function is a malfunctioning.

• ECM

B)

ECM EEP-ROM system is a malfunctioning.

C)

ECM self shut-off function is a malfunctioning.

P0605 ECM

EC-241

< COMPONENT DIAGNOSIS >

[VQ25DE, VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Diagnosis Procedure

INFOID:0000000003856704

1.

INSPECTION START

1.

Turn ignition switch ON.

2.

Erase DTC.

3.

Perform DTC CONFIRMATION PROCEDURE.
See 

EC-240, "DTC Logic"

.

Is the 1st trip DTC P0605 displayed again?

YES

>> GO TO 2.

NO

>> INSPECTION END

2.

REPLACE ECM

1.

Replace ECM.

2.

Go to 

EC-14, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Require-

ment"

.

>> INSPECTION END