Infiniti QX56 (JA60). Manual - part 13

B2126 DETENT SW

ADP-43

< COMPONENT DIAGNOSIS >

C

D

E

F

G

H

I

K

L

M

A

B

ADP

N

O

P

NO

>> GO TO 3

3.

 CHECK A/T SHIFT SELECTOR (PARK POSITION SWITCH) HARNESS

1. Turn ignition switch OFF.

2. Disconnect A/T shift selector and driver seat control unit.

3. Check continuity between driver seat control unit connector

B202 (A) terminal 21 and A/T shift selector connector M203 (B)

terminal 6.

4. Check continuity between driver seat control unit connector

B202 (A) terminal 21 and ground.

Is the inspection result normal?

YES

>> GO TO 4

NO

>> Repair or replace harness.

4.

 CHECK PARK POSITION SWITCH

Check continuity between A/T shift selector (park position switch)

terminals as follows.

Is the inspection result normal?

YES

>> GO TO 5

NO

>> Replace A/T shift selector. Refer to 

TM-165, "A/T Shift

Selector Removal and Installation"

.

5.

 CHECK INTERMITTENT INCIDENT

Refer to 

GI-38, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace driver seat control unit. Refer to 

ADP-174, "Removal and Installation"

.

NO

>> Repair or replace the malfunctioning part.

6 - 21

: Continuity should exist.

21 - Ground

: Continuity should not exist.

ALJIA0194ZZ

Terminals

Condition

Continuity

5

6

P position

Yes

Other than P position

No

ALJIA0486ZZ

ADP-44

< COMPONENT DIAGNOSIS >

B2128 UART COMMUNICATION LINE

B2128 UART COMMUNICATION LINE

Description

INFOID:0000000005147474

Driver seat control unit performs UART communication with the automatic drive positioner control unit using 2

communication lines, TX and RX line. Driver seat control unit receives the operation signals of pedal adjusting

switch, door mirror remote control switch, set switch and memory switch and the position signals of adjustable

pedal sensor and door mirror sensor from the automatic drive positioner control unit and transmits the opera-

tion request signal.

DTC Logic

INFOID:0000000005147475

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

 STEP 1

Turn ignition switch ON.

>> GO TO 2

2.

 STEP 2

Operate pedal adjusting switch for more than 2 seconds.

>> GO TO 3

3.

 PROCEDURE 3

Check “Self diagnostic result” with CONSULT-III.
Is the DTC detected? 

YES

>> Perform diagnosis procedure. Refer to 

ADP-44, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000005147476

Regarding Wiring Diagram information, refer to 

ADP-119, "Wiring Diagram"

.

1.

 CHECK UART COMMUNICATION LINE CONTINUITY

1. Turn ignition switch OFF.

2. Disconnect driver seat control unit and automatic drive posi-

tioner control unit.

3. Check continuity between driver seat control unit harness con-

nector and automatic drive positioner control unit harness con-

nector.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

B2128

UART COMM

The communication between driver seat control unit 
and automatic drive positioner control unit is interrupt-
ed for a period of time.

• UART communication line

(UART communication line is 
open or shorted)

• Driver seat control unit
• Automatic drive positioner 

control unit

Driver seat control 

unit connector

Terminal

Automatic drive positioner 

control unit connector

Terminal

Continuity 

PIIA4598E

B2128 UART COMMUNICATION LINE

ADP-45

< COMPONENT DIAGNOSIS >

C

D

E

F

G

H

I

K

L

M

A

B

ADP

N

O

P

4. Check continuity between driver seat control unit harness connector and ground.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-38, "Intermittent Incident"

.

NO

>> Repair or replace harness.

B202

1

M33

10

Yes

17

26

Driver seat control unit con-

nector

Terminal

Ground

Continuity 

B202

1

No

17

ADP-46

< COMPONENT DIAGNOSIS >

POWER SUPPLY AND GROUND CIRCUIT

POWER SUPPLY AND GROUND CIRCUIT

BCM
BCM : Diagnosis Procedure

INFOID:0000000005370325

Regarding Wiring Diagram information, refer to 

BCS-49, "Wiring Diagram"

.

1.

 CHECK FUSES AND FUSIBLE LINK

Check that the following fuses and fusible link are not blown.

Is the fuse blown?

YES

>> Replace the blown fuse or fusible link after repairing the affected circuit.

NO

>> GO TO 2

2.

 CHECK POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect BCM.

3. Check voltage between BCM harness connector and ground.

Is the measurement value normal?

YES

>> GO TO 3

NO

>> Repair or replace harness.

3.

 CHECK GROUND CIRCUIT

Terminal No.

Signal name

Fuses and fusible link No.

57

Battery power supply

22 (15A)

70

F (50A)

11

Ignition ACC or ON

4 (10A)

38

Ignition ON or START

59 (10A)

Connector

Terminals 

Power

source

Condition

Voltage (V) (Ap-

prox.)

(+)

(-)

M18

11

Ground

ACC 

power 

supply

Ignition 

switch 

ACC or 

ON

Battery voltage

38

Ground

Ignition 

power 

supply

Ignition 

switch ON 

or START

Battery voltage

M20

57

Ground

Battery 

power 

supply

Ignition 

switch 

OFF

Battery voltage

70

Ground

Battery 

power 

supply

Ignition 

switch 

OFF

Battery voltage

LIIA2415E