Infiniti G37 Coupe. Manual - part 167

AV

U121E AV CONTROL UNIT

AV-421

< COMPONENT DIAGNOSIS >

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U121E AV CONTROL UNIT

Description

INFOID:0000000001682750

Replace the AV control unit if this DTC is displayed. Refer to 

AV-608, "Exploded View"

.

DTC Logic

INFOID:0000000001558819

Part name

Description

AV CONTROL UNIT

• Integrates HDD (hard disk drive) allowing map data and music data to be 

stored.

• It is the master unit of the MULTI AV system, and it is connected to each control 

unit by communication. It operates each system according to communication 
signals from the AV control unit.

• The AV control unit includes the audio, hands-free phone, voice control, navi-

gation, satellite radio and vehicle information functions.

• It is connected to ECM and unified meter and A/C amp. via CAN communica-

tion to obtain necessary information for the vehicle information function.

• It is connected to BCM via CAN communication transmitting/receiving for the 

vehicle settings function.

• It inputs the illumination signals that are required for the display dimming con-

trol.

• It inputs the signals for driving status recognition (vehicle speed, reverse and 

parking brake). 

DTC

Display contents of 

CONSULT-III

DTC Detection Condition

Action to take

U121E

DSP COMM
[U121E]

Internal malfunction of AV control unit (DSP communica-
tion error) is detected.

Replace AV control unit.

AV-422

< COMPONENT DIAGNOSIS >

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U121F AV CONTROL UNIT

U121F AV CONTROL UNIT

Description

INFOID:0000000001682749

Replace the AV control unit if this DTC is displayed. Refer to 

AV-608, "Exploded View"

.

DTC Logic

INFOID:0000000001558821

Diagnosis Procedure

INFOID:0000000001558822

1.

CHECK AV CONTROL UNIT POWER SUPPLY AND GROUND CIRCUIT

Check AV control unit power supply and ground circuit. Refer to 

AV-433, "AV CONTROL UNIT : Diagnosis

Procedure"

.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Repair or replace malfunctioning parts.

Part name

Description

AV CONTROL UNIT

• Integrates HDD (hard disk drive) allowing map data and music data to be 

stored.

• It is the master unit of the MULTI AV system, and it is connected to each control 

unit by communication. It operates each system according to communication 
signals from the AV control unit.

• The AV control unit includes the audio, hands-free phone, voice control, navi-

gation, satellite radio and vehicle information functions.

• It is connected to ECM and unified meter and A/C amp. via CAN communica-

tion to obtain necessary information for the vehicle information function.

• It is connected to BCM via CAN communication transmitting/receiving for the 

vehicle settings function.

• It inputs the illumination signals that are required for the display dimming con-

trol.

• It inputs the signals for driving status recognition (vehicle speed, reverse and 

parking brake). 

DTC

Display contents of 

CONSULT-III

DTC Detection Condition

Action to take

U121F

INTERNAL COMM
[U121F]

Internal malfunction of AV control unit (internal communi-
cation error) is detected.

AV control unit power supply and 
ground circuit.

AV

U1204 GPS

AV-423

< COMPONENT DIAGNOSIS >

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U1204 GPS

Description

INFOID:0000000001682751

Replace the AV control unit if this DTC is displayed. Refer to 

AV-608, "Exploded View"

.

DTC Logic

INFOID:0000000001558824

Diagnosis Procedure

INFOID:0000000001558825

1.

PERFORM THE SELF-DIAGNOSIS

1.

Delete the self-diagnosis results. Turn ignition switch OFF.

2.

Turn ignition switch ON. Perform the self-diagnosis again. 

3.

Check that the DTC is detected again.

Is any DTC detected?

YES

>> Replace AV control unit.

NO

>> The intermittent malfunction caused by strong radio interference can be detected.

Part name

Description

AV CONTROL UNIT

• Integrates HDD (hard disk drive) allowing map data and music data to be 

stored.

• It is the master unit of the MULTI AV system, and it is connected to each control 

unit by communication. It operates each system according to communication 
signals from the AV control unit.

• The AV control unit includes the audio, hands-free phone, voice control, navi-

gation, satellite radio and vehicle information functions.

• It is connected to ECM and unified meter and A/C amp. via CAN communica-

tion to obtain necessary information for the vehicle information function.

• It is connected to BCM via CAN communication transmitting/receiving for the 

vehicle settings function.

• It inputs the illumination signals that are required for the display dimming con-

trol.

• It inputs the signals for driving status recognition (vehicle speed, reverse and 

parking brake). 

DTC

Display contents of 

CONSULT-III

DTC Detection Condition

Action to take

U1204

GPS CONN
[U1204]

Internal malfunction of AV control unit (GPS malfunction) 
is detected.

Replace AV control unit.

AV-424

< COMPONENT DIAGNOSIS >

[BOSE AUDIO WITH NAVIGATION]

U1205 GPS

U1205 GPS

Description

INFOID:0000000001682752

Replace the AV control unit if this DTC is displayed. Refer to 

AV-608, "Exploded View"

.

DTC Logic

INFOID:0000000001558827

Diagnosis Procedure

INFOID:0000000001558828

1.

PERFORM THE SELF-DIAGNOSIS

1.

Delete the self-diagnosis results. Turn ignition switch OFF.

2.

Turn ignition switch ON. Perform the self-diagnosis again. 

3.

Check that the DTC is detected again.

Is any DTC detected?

YES

>> Replace AV control unit.

NO

>> The intermittent malfunction caused by strong radio interference can be detected.

Part name

Description

AV CONTROL UNIT

• Integrates HDD (hard disk drive) allowing map data and music data to be 

stored.

• It is the master unit of the MULTI AV system, and it is connected to each control 

unit by communication. It operates each system according to communication 
signals from the AV control unit.

• The AV control unit includes the audio, hands-free phone, voice control, navi-

gation, satellite radio and vehicle information functions.

• It is connected to ECM and unified meter and A/C amp. via CAN communica-

tion to obtain necessary information for the vehicle information function.

• It is connected to BCM via CAN communication transmitting/receiving for the 

vehicle settings function.

• It inputs the illumination signals that are required for the display dimming con-

trol.

• It inputs the signals for driving status recognition (vehicle speed, reverse and 

parking brake). 

DTC

Display contents of 

CONSULT-III

DTC Detection Condition

Action to take

U1205

GPS ROM
[U1205]

Internal malfunction of AV control unit (GPS malfunction) 
is detected.

Replace AV control unit.