Infiniti EX35. Manual - part 460

DLK-54

< COMPONENT DIAGNOSIS >

[INTELLIGENT KEY SYSTEM]

U1000 CAN COMM CIRCUIT

COMPONENT DIAGNOSIS

U1000 CAN COMM CIRCUIT

Description

INFOID:0000000003729007

CAN (Controller Area Network) is a serial communication line for real time applications. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Modern
vehicle is equipped with many electronic control unit, 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.
CAN Communication Signal Chart. Refer to 

LAN-27, "CAN System Specification Chart"

.

DTC Logic

INFOID:0000000003729008

DTC DETECTION LOGIC

Diagnosis Procedure

INFOID:0000000003729009

1.

PERFORM SELF DIAGNOSTIC

1.

Turn ignition switch ON and wait for 2 seconds or more.

2.

Check “Self Diagnostic Result”.

Is “CAN COMM CIRCUIT” displayed?

YES

>> Refer to 

LAN-18, "Trouble Diagnosis Flow Chart"

.

NO

>> Refer to 

GI-38, "Intermittent Incident"

.

DTC

CONSULT-III display 

description

DTC Detection Condition

Possible cause

U1000

CAN COMM CIRCUIT

When BCM cannot communicate CAN com-
munication signal continuously for 2 seconds 
or more.

CAN communication system

U1010 CONTROL UNIT (CAN)

DLK-55

< COMPONENT DIAGNOSIS >

[INTELLIGENT KEY SYSTEM]

C

D

E

F

G

H

I

J

L

M

A

B

DLK

N

O

P

U1010 CONTROL UNIT (CAN)

DTC Logic

INFOID:0000000003729013

DTC DETECTION LOGIC

Diagnosis Procedure

INFOID:0000000003729014

1.

REPLACE BCM

When DTC [U1010] is detected, replace BCM.

>> Replace BCM. Refer to 

BCS-84, "Removal and Installation"

Special Repair Requirement

INFOID:0000000003729015

1.

REQUIRED WORK WHEN REPLACING BCM

Initialize control unit. Refer to CONSULT-III operation manual NATS-IVIS/NVIS.

>> Work end.

DTC

CONSULT-III display de-

scription

DTC Detection Condition

Possible cause

U1010

CONTROL UNIT (CAN)

BCM detected internal CAN communication circuit malfunction.

BCM

DLK-56

< COMPONENT DIAGNOSIS >

[INTELLIGENT KEY SYSTEM]

B2621 INSIDE KEY ANTENNA 1

B2621 INSIDE KEY ANTENNA 1

Description

INFOID:0000000003728998

Detects whether Intelligent Key is inside the vehicle.
Installed in the instrument center.

DTC Logic

INFOID:0000000003728999

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Perform inside key antenna (“INSIDE ANT DIAGNOSIS”) on Work Support” of “INTELLIGENT KEY”.

2.

Perform “INTELLIGENT KEY” Self Diagnostic Result.

Is inside key antenna DTC detected?

YES

>> Refer to 

DLK-56, "Diagnosis Procedure"

.

NO

>> Inside key antenna (instrument center) is OK.

Diagnosis Procedure

INFOID:0000000003729000

1.

CHECK INSIDE KEY ANTENNA INPUT SIGNAL 1

1.

Turn ignition switch OFF.

2.

Check signal between BCM harness connector and ground with oscilloscope.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 2.

2.

CHECK INSIDE KEY ANTENNA CIRCUIT

1.

Disconnect BCM and inside key antenna connector.

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

B2621

INSIDE ANTENNA 1 
CIRCUIT

An excessive high or low voltage from inside anten-
na is sent to BCM.

• Inside key antenna (instrument 

center)

• Between BCM and Inside key an-

tenna (instrument center)

(+)

(–)

Condition

Signal

(Reference value)

BCM

Connector

Terminal

M122

Instrument cen-

ter

78, 79

Ground

Place Intelligent Key inside the 
vehicle.

Place Intelligent Key outside 
the vehicle. 

JMKIA0062GB

JMKIA0063GB

B2621 INSIDE KEY ANTENNA 1

DLK-57

< COMPONENT DIAGNOSIS >

[INTELLIGENT KEY SYSTEM]

C

D

E

F

G

H

I

J

L

M

A

B

DLK

N

O

P

2.

Check continuity between BCM harness connector and inside key antenna (instrument center) harness
connector.

3.

Check continuity between BCM harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace harness.

3.

CHECK INSIDE KEY ANTENNA INPUT SIGNAL 2

1.

Replace inside key antenna (instrument center). (New antenna or other antenna)

2.

Connect BCM and inside key antenna (instrument center) connector.

3.

Check signal between BCM harness connector and ground with oscilloscope.

Is the inspection result normal?

YES

>> Replace inside key antenna (instrument center). Refer to 

DLK-258, "INSTRUMENT CENTER :

Removal and Installation"

.

NO

>> Replace BCM. Refer to 

BCS-84, "Removal and Installation"

.

4.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-38, "Intermittent Incident"

.

>> INSPECTION END

BCM

Inside key antenna (instrument center)

Continuity 

Connector

Terminal

Connector

Terminal

M122

78

M131

2

Existed

79

1

BCM

Ground

Continuity 

Connector

Terminal

M122

Instrument center

78

Not existed

79

(+)

(–)

Condition

Signal

(Reference value)

BCM

Connector

Terminal

M122

Instrument cen-

ter

78, 79

Ground

Place Intelligent Key inside the 
vehicle.

Place Intelligent Key outside 
the vehicle. 

JMKIA0062GB

JMKIA0063GB