Infiniti QX56 (Z62). Manual - part 409

DLK-102

< DTC/CIRCUIT DIAGNOSIS >

B2424 CLOSURE CONDITION

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace back door lock assembly.

B2425 AUTOMATIC BACK DOOR CONTROL UNIT

DLK-103

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

F

G

H

I

J

L

M

A

B

DLK

N

O

P

B2425 AUTOMATIC BACK DOOR CONTROL UNIT

DTC Logic

INFOID:0000000006225906

DTC DETECTION LOGIC

Diagnosis Procedure

INFOID:0000000006225907

1.

REPLACE AUTOMATIC BACK DOOR CONTROL MODULE

When DTC [B2425] is detected, replace automatic back door control module.

>> Replace automatic back door control module. Refer to 

DLK-262, "Removal and Installation"

.

DTC

CONSULT-III dis-

play description

DTC Detection Condition

Possible cause

B2425

AUTO BCK DR CNT 
UNIT

Automatic back door control unit detected CPU 
malfunction

Automatic back door control mod-
ule

DLK-104

< DTC/CIRCUIT DIAGNOSIS >

B2621 INSIDE ANTENNA

B2621 INSIDE ANTENNA

DTC Logic

INFOID:0000000006225908

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Select “INTELLIGENT KEY” of “BCM” using CONSULT-III.

2.

Select “INSIDE ANT DIAGNOSIS” in “WORK SUPPORT” mode.

3.

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

4.

Check BCM for DTC.

Is inside key antenna DTC detected?

YES

>> Refer to 

DLK-104, "Diagnosis Procedure"

.

NO

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

Diagnosis Procedure

INFOID:0000000006225909

1.

CHECK INSIDE KEY ANTENNA INPUT SIGNAL 1

1.

Turn ignition switch OFF.

2.

Check signal between BCM harness connector and ground using oscilloscope.

Is the inspection result normal?

YES

>> Replace BCM. Refer to 

BCS-81, "Removal and Installation"

.

NO

>> GO TO 2.

2.

CHECK INSIDE KEY ANTENNA CIRCUIT

1.

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

DTC

CONSULT-III display 

description

DTC detecting condition

Possible cause

B2621

INSIDE ANTENNA

An excessive high or low voltage from inside anten-
na (instrument center) is sent to BCM

• Inside key antenna (instrument 

center)

• Between BCM

∼

Inside key anten-

na (instrument center)

(+)

(–)

Condition

Signal

(Reference value)

BCM

Connector

Terminal

Instrument center

M71

84, 85

Ground

When Intelligent Key is in the 
antenna detection area

When Intelligent Key is not in 
the antenna detection area

JMKIA3839GB

JMKIA3838GB

B2621 INSIDE ANTENNA

DLK-105

< DTC/CIRCUIT DIAGNOSIS >

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 connector and inside key antenna (instrument center) connector.

3.

Check signal between BCM harness connector and ground using oscilloscope.

Is the inspection result normal?

YES

>> Replace inside key antenna (instrument center).

NO

>> Replace BCM. Refer to 

BCS-81, "Removal and Installation"

.

BCM

Inside key antenna (instrument center)

Continuity 

Connector

Terminal

Connector

Terminal

M71

84

M105

1

Existed

85

2

BCM

Ground

Continuity 

Connector

Terminal

M71

84

Not existed

85

(+)

(–)

Condition

Signal

(Reference value)

BCM

Connector

Terminal

Instrument center

M71

84, 85

Ground

When Intelligent Key is in 
the antenna detection area

When Intelligent Key is not 
in the antenna detection 
area

JMKIA3839GB

JMKIA3838GB