Infiniti M35/M45 Y50. Manual — part 840

TROUBLE DIAGNOSIS

LAN-9

[CAN FUNDAMENTAL]

C

D

E

F

G

H

I

J

L

M

A

B

LAN

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.

●

When data link connector branch line is open, the screen-display of the CONSULT-II “SELECT SYSTEM”
screen may be the same as when the CAN communication line has short-circuit. However, symptoms dif-
fer depending on the case. See below chart for the differences.

SKIB8739E

Unit name

Symptom

ECM

Normal operation.

BCM

EPS control unit

Combination meter

ABS actuator and electric unit (control unit)

TCM

IPDM E/R

SELECT SYSTEM

(CONSULT-II)

Difference of symptom

Data link connector branch line open cir-
cuit

All Diag on CAN units are not
indicated.

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-10

[CAN FUNDAMENTAL]

TROUBLE DIAGNOSIS

Example: Main Line Between Data Link Connector and ABS Actuator and Electric Unit (Con-
trol Unit) Open 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
wiper 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.

TROUBLE DIAGNOSIS

LAN-11

[CAN FUNDAMENTAL]

C

D

E

F

G

H

I

J

L

M

A

B

LAN

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

SKIB8741E

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.

LAN-12

[CAN FUNDAMENTAL]

TROUBLE DIAGNOSIS

Self-Diagnosis

NKS004HE

DTC

Self-diagnosis item

(CONSULT-II indication)

DTC detection condition

Inspection/Action

U1000

CAN COMM CIRCUIT

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

Refer to

LAN-15,

"TROUBLE DIAG-
NOSES WORK FLOW"

.

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
communication signal other than OBD (emis-
sion-related diagnosis) for 2 seconds or more.

U1002

SYSTEM COMM

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

Start the inspection.
Refer to the applicable
section of the indicated
control unit.

U1010

CONTROL UNIT [CAN]

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

Replace the control unit
indicating “U1010”.