Infiniti G37 Coupe. Manual - part 274

BRC-70

< COMPONENT DIAGNOSIS >

[VDC/TCS/ABS]

U1000, U1002 CAN COMM CIRCUIT

U1000, U1002 CAN COMM CIRCUIT

Description

INFOID:0000000001635120

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, 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.

DTC Logic

INFOID:0000000001635121

DTC DETECTION LOGIC

Diagnosis Procedure

INFOID:0000000001635122

1.

CHECK CONNECTOR

1.

Turn ignition switch OFF.

2.

Disconnect ABS actuator and electric unit (control unit) connector.

3.

Check terminal for deformation, disconnection, looseness, and so on. If any malfunction is found, repair or
replace terminal.

4.

Reconnect connector and perform self-diagnosis.

Is above displayed on the self-diagnosis display?

YES

>> Go to 

LAN-25, "CAN System Specification Chart"

.

NO

>> INSPECTION END

Special Repair Requirement

INFOID:0000000001635123

1.

ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION

Always perform the neutral position adjustment for the steering angle sensor, when replacing the ABS actua-
tor and electric unit (control unit). Refer to 

BRC-8, "ADJUSTMENT OF STEERING ANGLE SENSOR NEU-

TRAL POSITION : Description"

.

>> END

DTC

Display item

Malfunction detected condition

Possible cause

U1000

CAN COMM CIRCUIT

When ABS actuator and electric unit (control unit) is not 
transmitting or receiving CAN communication signal for 2 
seconds or more.

• CAN communication line
• ABS actuator and electric unit 

(control unit)

U1002

SYSTEM COMM

When ABS actuator and electric unit (control unit) is not 
transmitting or receiving CAN communication signal for 2 
seconds or less.

Self-diagnosis results

CAN COMM CIRCUIT

SYSTEM COMM

PARKING BRAKE SWITCH

BRC-71

< COMPONENT DIAGNOSIS >

[VDC/TCS/ABS]

C

D

E

G

H

I

J

K

L

M

A

B

BRC

N

O

P

PARKING BRAKE SWITCH

Description

INFOID:0000000001635124

The parking brake switch converts the status of the parking brake lever (M/T models) or the parking brake
pedal (A/T models) to an electric signal and transmits it to the ABS actuator and electric unit (control unit).

Component Function Check

INFOID:0000000001635125

1.

CHECK PARKING BRAKE SWITCH OPERATION

Operate the parking brake lever (M/T models) or the parking brake pedal (A/T models). Then check that the
brake warning lamp in the combination meter turns on/off correctly.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to diagnosis procedure. Refer to 

BRC-71, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000001635126

1.

CHECK PARKING BRAKE SWITCH

1.

Turn ignition switch OFF.

2.

Disconnect parking brake switch connector.

3.

Check continuity between parking brake switch connector terminal.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace parking brake switch.

2.

CHECK COMBINATION METER

Check if the indication and operation of combination meter are normal. Refer to 

MWI-35, "Diagnosis Descrip-

tion"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace combination meter.

3.

CHECK DATA MONITOR

On “DATA MONITOR”, select “PARK BRAKE SW” and perform the parking brake switch inspection.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Check unified meter and A/C amp. Refer to 

MWI-37, "CONSULT-III Function (METER/M&A)"

.

Condition

Brake warning lamp illumination status

When the parking brake switch is opera-
tion

ON

When the parking brake switch is not oper-
ation.

OFF

Parking brake switch

—

Condition

Continuity

Connector

Terminal

B14 (M/T models)

E107 (A/T models)

1

Ground

When the parking brake switch is operated.

Existed

When the parking brake switch is not operated.

Not existed

Condition

PARK BRAKE SW (DATA MONITOR)

Parking brake switch is active

On

Parking brake switch is inactive

Off

BRC-72

< COMPONENT DIAGNOSIS >

[VDC/TCS/ABS]

PARKING BRAKE SWITCH

Component Inspection

INFOID:0000000001635127

1.

CHECK PARKING BRAKE SWITCH

1.

Turn ignition switch OFF.

2.

Disconnect parking brake switch connector.

3.

Check continuity between parking brake switch connector terminal.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace parking brake switch.

Parking brake switch

—

Condition

Continuity

Connector

Terminal

B14 (M/T models)

E107 (A/T models)

1

Ground

When the parking brake switch is operated.

Existed

When the parking brake switch is not operated.

Not existed

VDC OFF SWITCH

BRC-73

< COMPONENT DIAGNOSIS >

[VDC/TCS/ABS]

C

D

E

G

H

I

J

K

L

M

A

B

BRC

N

O

P

VDC OFF SWITCH

Description

INFOID:0000000001635128

VDC OFF switch can deactivate (turn OFF) the VDC/TCS function by pressing the VDC OFF switch.

Component Function Check

INFOID:0000000001635129

1.

CHECK VDC OFF SWITCH OPERATION

Turn ON/OFF the VDC OFF switch and check that the VDC OFF indicator lamp in the combination meter turns
ON/OFF correctly.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to diagnosis procedure. Refer to 

BRC-73, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000001635130

1.

CHECK VDC OFF SWITCH

1.

Turn ignition switch OFF.

2.

Disconnect VDC OFF switch connector.

3.

Check continuity between VDC OFF switch connector terminals.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> VDC OFF switch is malfunctioning. Replace VDC OFF switch.

2.

CHECK VDC OFF SWITCH HARNESS

1.

Disconnect ABS actuator and electric unit (control unit) connector.

2.

Check continuity between VDC OFF switch connector terminals and ABS actuator and electric unit (con-
trol unit) connector terminal and/or ground.

Is the inspection result normal?

Condition

VDC OFF indicator lamp illumination status

VDC OFF switch: ON

ON

VDC OFF switch: OFF

OFF

VDC OFF switch

Condition

Continuity

Connector

Terminal

M19

1 

−

 2

When VDC OFF switch is hold pressed.

Existed

When releasing VDC OFF switch.

Not existed

ABS actuator and electric unit 

(control unit)

VDC OFF switch

Continuity

Connector

Terminal

Connector

Terminal

E41

31

M19

1

Existed

ABS actuator and electric unit (control unit)

—

Continuity

Connector

Terminal

E41

31

Ground

Not existed

VDC OFF switch

—

Continuity

Connector

Terminal

M19

2

Ground

Existed