Nissan X-Trail 32. Manual - part 1493

LAN-12

< SYSTEM DESCRIPTION >

[CAN FUNDAMENTAL]

TROUBLE DIAGNOSIS

Example: Data link connector branch line open circuit

NOTE:
• When data link connector branch line is open, transmission and reception of CAN communication signals

are not affected. Therefore, no symptoms occur. However, be sure to repair malfunctioning circuit.

• The model (all units on CAN communication system are Diag on CAN) cannot perform CAN diagnosis with

CONSULT if the following error occurs. The error is judged by the symptom.

EPS control unit

Normal operation.

Combination meter

• Shift position indicator and OD OFF indicator turn OFF.
• Warning lamps turn ON.

ABS actuator and electric unit (control unit)

Normal operation.

TCM

No impact on operation.

IPDM E/R

Normal operation.

Unit name

Symptom

SKIB8739E

Unit name

Symptom

ECM

Normal operation.

BCM

EPS control unit

Combination meter

ABS actuator and electric unit (control unit)

TCM

IPDM E/R

Error

Difference of symptom

Data link connector branch line open circuit

Normal operation.

CAN-H, CAN-L harness short-circuit

Most of the units which are connected to the CAN communication 
system enter fail-safe mode or are deactivated.

LAN

TROUBLE DIAGNOSIS

LAN-13

< SYSTEM DESCRIPTION >

[CAN FUNDAMENTAL]

C

D

E

F

G

H

I

J

K

L

B

A

O

P

N

Example: Main Line Between Data Link Connector and ABS Actuator and Electric Unit (Control Unit) Open Circuit

Example: CAN-H, CAN-L Harness Short Circuit

SKIB8740E

Unit name

Symptom

ECM

Engine torque limiting is affected, and shift harshness increases.

BCM

• Reverse warning chime does not sound.
• The front wiper moves under continuous operation mode even though the front wip-

er switch being in the intermittent position.

EPS control unit

The steering effort increases.

Combination meter

• The shift position indicator and OD OFF indicator turn OFF.
• The speedometer is inoperative.
• The odo/trip meter stops.

ABS actuator and electric unit (control unit)

Normal operation.

TCM

No impact on operation.

IPDM E/R

When the ignition switch is ON,
• The headlamps (Lo) turn ON.
• The cooling fan continues to rotate.

SKIB8741E

LAN-14

< SYSTEM DESCRIPTION >

[CAN FUNDAMENTAL]

TROUBLE DIAGNOSIS

CAN Diagnosis with CONSULT

INFOID:0000000010715292

CAN diagnosis on CONSULT extracts the root cause by receiving the following information.
• Response to the system call
• Control unit diagnosis information
• Self-diagnosis
• CAN diagnostic support monitor

Self-Diagnosis

INFOID:0000000010715293

If communication signals cannot be transmitted or received among units communicating via CAN communica-
tion line, CAN communication-related DTC is displayed on the CONSULT “Self Diagnostic Result” screen.
NOTE:
The following table shows examples of CAN communication-related DTC. For other DTC, refer to the applica-
ble sections.

CAN Diagnostic Support Monitor

INFOID:0000000010715294

MONITOR ITEM (CONSULT)

Unit name

Symptom

ECM

• Engine torque limiting is affected, and shift harshness increases.
• Engine speed drops.

BCM

• Reverse warning chime does not sound.
• The front wiper moves under continuous operation mode even though the front 

wiper switch being in the intermittent position.

• The room lamp does not turn ON.
• The engine does not start (if an error or malfunction occurs while turning the igni-

tion switch OFF.)

• The steering lock does not release (if an error or malfunction occurs while turning 

the ignition switch OFF.)

EPS control unit

The steering effort increases.

Combination meter

• The tachometer and the speedometer do not move.
• Warning lamps turn ON.
• Indicator lamps do not turn ON.

ABS actuator and electric unit (control unit)

Normal operation.

TCM

No impact on operation.

IPDM E/R

When the ignition switch is ON,
• The headlamps (Lo) turn ON.
• The cooling fan continues to rotate.

DTC

Self-diagnosis item

 (CONSULT indication)

DTC detection condition

Inspection/Action

U1000

CAN COMM CIRCUIT

ECM

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

Start the inspection. Re-
fer to the applicable sec-
tion of the indicated 
control unit.

Except 
for ECM

When a control unit (except for ECM) is not 
transmitting or receiving CAN communication 
signal for 2 seconds or more.

U1001

CAN COMM CIRCUIT

When ECM is not transmitting or receiving CAN communi-
cation signal other than OBD (emission-related diagnosis) 
for 2 seconds or more.

U1002

SYSTEM COMM

When a control unit is not transmitting or receiving CAN 
communication signal for 2 seconds or less.

U1010

CONTROL UNIT(CAN)

When an error is detected during the initial diagnosis for 
CAN controller of each control unit.

Replace the control unit 
indicating “U1010”.

LAN

TROUBLE DIAGNOSIS

LAN-15

< SYSTEM DESCRIPTION >

[CAN FUNDAMENTAL]

C

D

E

F

G

H

I

J

K

L

B

A

O

P

N

Example: CAN DIAG SUPPORT MNTR indication

Without PAST

With PAST

MONITOR ITEM (ON-BOARD DIAGNOSIS)

NOTE:
For some models, CAN communication diagnosis result is received from the vehicle monitor.

JSMIA0964GB

Item

PRESENT

Description

Initial diagnosis

OK

Normal at present

NG

Control unit error (Except for some control units)

Transmission diagnosis

OK

Normal at present

UNKWN

Unable to transmit signals for 2 seconds or more.

Diagnosis not performed

Control unit name

(Reception diagnosis)

OK

Normal at present

UNKWN

Unable to receive signals for 2 seconds or more.

Diagnosis not performed

No control unit for receiving signals. (No applicable optional parts)

Item

PRESENT

PAST

Description

Transmission diagnosis

OK

OK

Normal at present and in the past

1 – 39

Normal at present, but unable to transmit signals for 2 seconds or more 
in the past. (The number indicates the number of ignition switch cycles 
from OFF to ON.)

UNKWN

0

Unable to transmit signals for 2 seconds or more at present.

Control unit name

(Reception diagnosis)

OK

OK

Normal at present and in the past

1 – 39

Normal at present, but unable to receive signals for 2 seconds or more 
in the past. (The number indicates the number of ignition switch cycles 
from OFF to ON.)

UNKWN

0

Unable to receive signals for 2 seconds or more at present.

Not diagnosed

–

Diagnosis not performed.

No control unit for receiving signals. (No applicable optional parts)