Infiniti G37 Coupe. Manual - part 71

AV

U1255 SATELLITE RADIO TUNER

AV-37

< COMPONENT DIAGNOSIS >

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C

D

E

F

G

H

I

J

K

L

M

B

A

O

P

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace AV control unit.

4.

CHECK SATELLITE RADIO TUNER

1.

Turn ignition switch OFF.

2.

Disconnect AV control unit connector.

3.

Connect satellite radio tuner.

4.

Turn ignition switch ON.

5.

Check voltage between satellite radio tuner harness connector terminal 10 and ground.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace satellite radio tuner.

28 - Ground

: Approx 7.5 V

29 - Ground

: Approx 7.0 V

10 - Ground

: Approx 7.0 V

AV-38

< COMPONENT DIAGNOSIS >

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U1300 AV COMM CIRCUIT

U1300 AV COMM CIRCUIT

Description

INFOID:0000000001559145

U1300 is indicated when malfunction occurs in communication signal of multi AV system. Indicated simulta-
neously, without fail, with the malfunction of control units connected to AV control unit with communication line.
Determine the possible malfunction cause from the table below.

SELF-DIAGNOSIS RESULTS DISPLAY ITEM

DTC

Display contents of 

CONSULT-III

DTC Detection Condition

Possible causes

U1300
U1240

• AV COMM CIRCUIT

[U1300]

• SWITCH CONN

[U1240]

• Multifunction switch power supply and ground circuit 

malfunction is detected.

• Malfunction is detected in AV communication circuit be-

tween AV control unit and multifunction switch.

• Malfunction is detected in AV communication signal be-

tween AV control unit and multifunction switch.

• Multifunction switch power supply 

and ground circuits.

• AV communication circuit between 

AV control unit and multifunction 
switch.

AV

POWER SUPPLY AND GROUND CIRCUIT

AV-39

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C

D

E

F

G

H

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J

K

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B

A

O

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POWER SUPPLY AND GROUND CIRCUIT

AV CONTROL UNIT

AV CONTROL UNIT : Diagnosis Procedure

INFOID:0000000001559146

1.

CHECK FUSE

Check for blown fuses.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Be sure to eliminate cause of malfunction before installing new fuse. 

2.

CHECK POWER SUPPLY CIRCUIT

Check voltage between AV control unit harness connectors and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Check harness between AV control unit and fuse.

3.

CHECK GROUND CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect AV control unit connectors.

3.

Check continuity between AV control unit harness connectors and ground.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Repair harness or connector.

DISPLAY UNIT

DISPLAY UNIT : Diagnosis Procedure

INFOID:0000000001689651

1.

CHECK POWER SUPPLY CIRCUIT (DISPLAY SIDE)

Check voltage between display unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 2.

Power source

Fuse No.

Battery

34

Ignition switch ACC or ON

19

Ignition switch ON or START 

3

Signal name

Connector No.

Terminal No.

Ignition switch position

Value (Approx.)

Battery power supply

M81

19

OFF

12 V

ACC power supply

M81

7

ACC

12 V

Ignition signal

M85

104

ON

12 V

Signal name

Connector No.

Terminal No.

Ignition switch position

Continuity 

Ground

M81

8

OFF

Existed

M81

20

M85

85

Signal name

Connector No.

Terminal No.

Ignition switch position

Value (Approx.)

Inverter VCC

M71

2

ACC

9 V

Signal VCC

3

AV-40

< COMPONENT DIAGNOSIS >

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POWER SUPPLY AND GROUND CIRCUIT

2.

CHECK POWER SUPPLY CIRCUIT (CONTINUITY)

1.

Turn ignition switch OFF.

2.

Disconnect the harness connector between display unit and AV control unit.

3.

Check continuity between display unit harness connector M71 and AV control unit harness connector
M83. 

4.

Check continuity between display unit harness connector M71 and ground. 

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair harness or connector.

3.

CHECK POWER SUPPLY CIRCUIT (AV CONTROL UNIT SIDE)

1.

Connect the AV control unit harness connector.

2.

Turn ignition switch ACC.

3.

Check voltage between AV control unit harness connector and ground.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replacement of AV control unit. 

4.

CHECK GROUND CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect display unit connector.

3.

Check continuity between display unit harness connectors and ground.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Repair harness or connector.

MULTIFUNCTION SWITCH

MULTIFUNCTION SWITCH : Diagnosis Procedure

INFOID:0000000001689652

1.

CHECK FUSE

Check for blown fuses.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Be sure to eliminate cause of malfunction before installing new fuse.

Signal name

Display unit (M71)

AV control unit (M83)

Continuity

Inverter VCC

2

59

Existed

Signal VCC

3

47

Existed

Signal name

Display unit (M71)

—

Continuity

Inverter VCC

2

Ground

Not existed

Signal VCC

3

Ground

Not existed

Signal name

Connector No.

Terminal No.

Ignition switch position

Value (Approx.)

Inverter VCC

M83

59

ACC

9 V

Signal VCC

47

Signal name

Connector No.

Terminal No.

Ignition switch position

Continuity 

Ground

M71

1

OFF

Existed

Power source

Fuse No.

Ignition switch ACC or ON

19