Nissan X-Trail 32. Manual — part 760

U1044 ENG COMM CIRCUIT

EC-169

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

U1044 ENG COMM CIRCUIT

DTC Description

INFOID:0000000010775100

DTC DETECTION LOGIC

POSSIBLE CAUSE

• Harness or connectors

(LIN communication circuit is open or shorted.)

• Generator

FAIL-SAFE

Not applicable

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.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition ON and wait at least 10 seconds.

2.

Check DTC.

Is DTC detected?

YES

>> Proceed to

EC-169, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010775101

1.

CHECK LIN COMMUNICATION CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector and alternator harness connector.

3.

Check the continuity between ECM harness connector and alternator harness connector.

4.

Also check harness for short to power and short to ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace error-detected parts.

2.

REPLACE GENERATOR

1.

Replace alternator. Refer to

CHG-44, "MR20DD : Removal and Installation"

.

2.

Erase DTC.

3.

Perform DTC confirmation procedure again. Refer to

EC-169, "DTC Description"

.

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

U1044

ENG COMM CIRCUIT
(Engine communication circuit)

A signal voltage of LIN communication between ECM and generator is ex-
cessively low or excessively high.

+

−

Continuity

ECM

Alternator

Connector

Terminal

Connector

Terminal

F7

45

F15

2

Existed

EC-170

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

U1044 ENG COMM CIRCUIT

Is DTC detected again?

YES

>> Replace ECM. Refer to

EC-430, "Removal and Installation"

.

NO

>> INSPECTION END

U1050, U1051 LIN COMMUNICATION

EC-171

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

U1050, U1051 LIN COMMUNICATION

DTC Description

INFOID:0000000010775102

DTC DETECTION LOGIC

POSSIBLE CAUSE

• Harness or connectors

(LIN communication circuit is open or shorted.)

• Generator
• ECM

FAIL-SAFE

Not applicable

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.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition ON and wait at least 10 seconds.

2.

Check DTC.

Is DTC detected?

YES

>> Proceed to

EC-171, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010775103

1.

CHECK LIN COMMUNICATION CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector and alternator harness connector.

3.

Check the continuity between ECM harness connector and alternator harness connector.

4.

Also check harness for short to power and short to ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace error-detected parts.

2.

REPLACE GENERATOR

1.

Replace alternator. Refer to

CHG-44, "MR20DD : Removal and Installation"

.

2.

Erase DTC.

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

U1050

LIN COMMUNICATION

ECM detects LIN communication error.

U1051

+

−

Continuity

ECM

Alternator

Connector

Terminal

Connector

Terminal

F7

45

F15

2

Existed

EC-172

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

U1050, U1051 LIN COMMUNICATION

3.

Perform DTC confirmation procedure again. Refer to

EC-171, "DTC Description"

.

Is DTC detected again?

YES

>> Replace ECM. Refer to

EC-430, "Removal and Installation"

.

NO

>> INSPECTION END