Infiniti G37 Coupe. Manual - part 16

ADP-58

< COMPONENT DIAGNOSIS >

B2126 DETENT SW

3.

Check continuity between driver seat control unit harness connector and A/T device harness connector.

4.

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

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace harness.

4.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-38, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace driver seat control unit.

NO

>> Repair or replace the malfunctioning part.

Driver seat control unit connec-

tor

Terminal

A/T device connector

Terminal

Continuity

B503

21

M137

11

Existed

Driver seat control unit connec-

tor

Terminal

Ground

Continuity 

B503

21

Not existed

B2127 PARKING BRAKE SWITCH

ADP-59

< COMPONENT DIAGNOSIS >

C

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ADP

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B2127 PARKING BRAKE SWITCH

Description

INFOID:0000000001693668

• Parking brake switch is installed on parking brake lever. It is turned ON when the parking brake is applied.
• The driver seat control unit judges that the parking brake is engaged if continuity exists in this circuit.

DTC Logic

INFOID:0000000001693669

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

STEP 1

Drive the vehicle at 7 km/h (4 MPH) or more.

>> GO TO 2.

2.

STEP 2

Check “Self Diagnostic Result” with CONSULT-III.

Is the DTC detected? 

YES

>> Perform diagnosis procedure. Refer to 

ADP-59, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001693670

1.

CHECK PARKING BRAKE SWITCH SIGNAL

1.

Turn ignition switch ON.

2.

Select “PARK BRAKE SW” in “Data Monitor” mode with CONSULT-III. 

3.

Check parking brake switch signal under the following condition. 

Is the status normal?

YES

>> GO TO 4.

NO

>> GO TO 2.

2.

CHECK PARKING BRAKE SWITCH HARNESS CONTINUITY

1.

Turn ignition switch OFF.

2.

Disconnect driver seat control unit connector and parking brake switch connector.

3.

Check continuity between driver seat control unit harness connector and parking brake switch harness
connector.

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

B2127

PARKING BRAKE

Parking brake is engaged and the vehicle speed of 
7 km/h (4MPH) or more is detected.

• Harness and connectors

(Parking brake switch circuit is 
opened/shorted.)

• Parking brake switch
• Combination meter

(CAN communication)

• Driver seat control unit

Monitor item

Condition

Status

PARK BRAKE SW

Parking brake

Applied

ON

Release

OFF

Driver seat control unit connec-

tor

Terminal

Parking brake switch

Terminal

Continuity 

B503

8

B14

1

Existed

ADP-60

< COMPONENT DIAGNOSIS >

B2127 PARKING BRAKE SWITCH

4.

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

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace harness.

3.

CHECK PARKING BRAKE SWITCH

Refer to 

ADP-60, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Adjust or replace parking brake switch.

4.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-38, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace driver seat control unit.

NO

>> Repair or replace the malfunctioning part.

Component Inspection

INFOID:0000000001693671

1.

CHECK PARKING BRAKE SWITCH

1.

Turn ignition switch OFF.

2.

Disconnect parking brake switch connector.

3.

Check continuity between parking brake switch terminal and ground part of parking brake switch.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Adjust or replace parking brake switch.

Driver seat control unit connec-

tor

Terminal

Ground

Continuity 

B503

8

Not existed

Terminal

Condition

Continuity

Parking brake switch

1

Ground part of

 parking brake switch

Parking brake

Applied

Existed

Other than above

Not existed

B2128 UART COMMUNICATION LINE

ADP-61

< COMPONENT DIAGNOSIS >

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B2128 UART COMMUNICATION LINE

Description

INFOID:0000000001693672

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 tilt & telescopic
switch, door mirror remote control switch, set switch and memory switch and the position signals of tilt & tele-
scopic sensor and door mirror sensor from the automatic drive positioner control unit and transmits the opera-
tion request signal.

DTC Logic

INFOID:0000000001693673

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

STEP 1

Turn ignition switch ON.

>> GO TO 2.

2.

STEP 2

Operate tilt & telescopic 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-61, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001693674

1.

CHECK UART COMMUNICATION LINE CONTINUITY

1.

Turn ignition switch OFF.

2.

Disconnect driver seat control unit connector and automatic drive positioner control unit connector.

3.

Check continuity between driver seat control unit harness connector and automatic drive positioner con-
trol unit harness connector.

4.

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

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

B2128

UART COMM

The communication between driver seat control unit 
and auto drive positioner control unit is interrupted 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 connec-

tor

Terminal

Automatic drive positioner con-

trol unit connector

Terminal

Continuity 

B503

1

M51

10

Existed

17

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