Nissan X-Trail 32. Manual - part 759

U0101 CAN COMM CIRCUIT

EC-165

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

U0101 CAN COMM CIRCUIT

DTC Description

INFOID:0000000010775094

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. 
Each control unit transmits/receives data but selectively reads required data only.

DTC DETECTION LOGIC

POSSIBLE CAUSE

Harness or connectors (CAN communication line is open or shorted)

FAIL-SAFE

Not applicable

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON and wait at least 3 seconds.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-165, "Diagnosis Procedure"

.

NO-1

>> To check malfunction symptom before repair: Refer to 

GI-44, "Intermittent Incident"

.

NO-2

>> Confirmation after repair: INSPECTION END

Diagnosis Procedure

INFOID:0000000010775095

Perform the trouble diagnosis for CAN communication system. Refer to 

LAN-17, "Trouble Diagnosis Flow

Chart"

.

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

U0101

LOST COMM (TCM)
(Lost communication with TCM)

When ECM is not transmitting or receiving CAN communication signal of 
OBD (emission-related diagnosis) for 2 seconds or more.

EC-166

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

U1001 CAN COMM CIRCUIT

U1001 CAN COMM CIRCUIT

DTC Description

INFOID:0000000010775096

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. 
Each control unit transmits/receives data but selectively reads required data only.

DTC DETECTION LOGIC

POSSIBLE CAUSE

Harness or connectors (CAN communication line is open or shorted)

FAIL-SAFE

Not applicable

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON and wait at least 3 seconds.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-166, "Diagnosis Procedure"

.

NO-1

>> To check malfunction symptom before repair: Refer to 

GI-44, "Intermittent Incident"

.

NO-2

>> Confirmation after repair: INSPECTION END

Diagnosis Procedure

INFOID:0000000010775097

Perform the trouble diagnosis for CAN communication system. Refer to 

LAN-17, "Trouble Diagnosis Flow

Chart"

.

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

U1001

CAN COMM CIRCUIT
(CAN COMM CIRCUIT)

When ECM is not transmitting or receiving CAN communication signal oth-
er than OBD (emission-related diagnosis) for 2 seconds or more.

U1040 ENG COMM CIRCUIT

EC-167

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

U1040 ENG COMM CIRCUIT

DTC Description

INFOID:0000000010775098

DTC DETECTION LOGIC

POSSIBLE CAUSE

• Harness or connectors

(LIN communication circuit is open or shorted.)

• 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-167, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010775099

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-167, "DTC Description"

.

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

U1040

ENG COMM CIRCUIT
(Engine communication circuit)

ECM cannot transmit a communication signal to generator.

+

−

Continuity

ECM

Alternator

Connector

Terminal

Connector

Terminal

F7

45

F15

2

Existed

EC-168

< DTC/CIRCUIT DIAGNOSIS >

[MR20DD]

U1040 ENG COMM CIRCUIT

Is DTC detected again?

YES

>> Replace ECM. Refer to 

EC-430, "Removal and Installation"

.

NO

>> INSPECTION END