2008 INFINITI QX56 audio

AV-50
< COMPONENT DIAGNOSIS >[AUDIO SYSTEM]
U121C AV CONTROL UNIT
U121C AV CONTROL UNIT
DescriptionINFOID:0000000001696071
Replace the AV control unit if this DTC is displayed. Refer to
AV-164, "Removal and Installation".
DTC LogicINFOID:0000000001696072
Part name Description
AV CONTROL UNIT • Integrates HDD (hard disk dr
ive) 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 means of communication. It operates each system according to com-
munication signals from the AV control unit.
• The AV control unit includes the audio, hands-free phone, voice control, navi- gation, and vehicle information functions.
• It is connected to ECM and combination meter via CAN communication to ob-
tain necessary information for the vehicle information function.
• It inputs the automatic brightness ON/OFF signals that are required for the dis- play dimming control.
• 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
U121C HDD-ACCESS
[U121C] Internal malfunction
of AV control unit (HDD access error)
is detected. Replace AV control unit. Refer to
AV-
164, "Removal and Installation".
Revision: March 2010 2008 QX56

AV
U121D AV CONTROL UNITAV-51
< COMPONENT DIAGNOSIS > [AUDIO SYSTEM]
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U121D AV CONTROL UNIT
DescriptionINFOID:0000000001696073
Replace the AV control unit if this DTC is displayed. Refer to AV-164, "Removal and Installation".
DTC LogicINFOID:0000000001696074
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 means of communication. It operates each system according to com-
munication signals from the AV control unit.
• The AV control unit includes the audio, hands-free phone, voice control, navi- gation, and vehicle information functions.
• It is connected to ECM and combination meter via CAN communication to ob-
tain necessary information for the vehicle information function.
• It inputs the automatic brightness ON/OFF signals that are required for the dis- play dimming control.
• 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
U121D DSP CONN
[U121D] Internal malfunction of AV control unit (DSP connection
error) is detected. Replace AV control unit. Refer to
AV-
164, "Removal and Installation".
Revision: March 2010 2008 QX56

AV-52
< COMPONENT DIAGNOSIS >[AUDIO SYSTEM]
U121E AV CONTROL UNIT
U121E AV CONTROL UNIT
DescriptionINFOID:0000000001696075
Replace the AV control unit if this DTC is displayed. Refer to
AV-164, "Removal and Installation".
DTC LogicINFOID:0000000001696076
Part name Description
AV CONTROL UNIT • Integrates HDD (hard disk dr
ive) 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 means of communication. It operates each system according to com-
munication signals from the AV control unit.
• The AV control unit includes the audio, hands-free phone, voice control, navi- gation, and vehicle information functions.
• It is connected to ECM and combination meter via CAN communication to ob-
tain necessary information for the vehicle information function.
• It inputs the automatic brightness ON/OFF signals that are required for the dis- play dimming control.
• 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. Refer to
AV-
164, "Removal and Installation".
Revision: March 2010 2008 QX56

AV
U121F AV CONTROL UNITAV-53
< COMPONENT DIAGNOSIS > [AUDIO SYSTEM]
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U121F AV CONTROL UNIT
DescriptionINFOID:0000000001696077
DTC LogicINFOID:0000000001696078
Diagnosis ProcedureINFOID:0000000001696079
1.CHECK AV CONTROL UNIT POWE R SUPPLY AND GROUND CIRCUIT
Check audio control unit power supply and ground circuit. Refer to AV-63, "
AV CONTROL UNIT : Diagnosis
Procedure".
Is inspection result OK?
YES >> Inspection end.
NO >> Repair 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 means of communication. It operates each system according to com-
munication signals from the AV control unit.
• The AV control unit includes the audio, hands-free phone, voice control, navi-
gation, and vehicle information functions.
• It is connected to ECM and combination meter via CAN communication to ob- tain necessary information for the vehicle information function.
• It inputs the automatic brightness ON/OFF signals that are required for the dis- play dimming control.
• 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.
Revision: March 2010
2008 QX56

AV-54
< COMPONENT DIAGNOSIS >[AUDIO SYSTEM]
U1220 AV CONTROL UNIT
U1220 AV CONTROL UNIT
DescriptionINFOID:0000000001696080
Refer to
AV- 9 , "System Description".
DTC LogicINFOID:0000000001696081
DTC DETECTION LOGIC
DTC CONSULT-III display Detection conditionAction to take
U1220 XM SERIAL COMM
[U1220] An internal malfunction is detected in AV control unit (sat-
ellite radio tuner communication malfunction). Replace AV control unit. Refer
to
AV- 1 6 4 , "
Removal and Instal-
lation".
Revision: March 2010 2008 QX56

AV
U1243 DISPLAY UNITAV-55
< COMPONENT DIAGNOSIS > [AUDIO SYSTEM]
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U1243 DISPLAY UNIT
DescriptionINFOID:0000000001696082
DTC LogicINFOID:0000000001696083
Diagnosis ProcedureINFOID:0000000001696084
1.CHECK DISPLAY UNIT POWER SUPPLY AND GROUND CIRCUIT
Check display unit power supply and ground circuit. Refer to AV-64, "
DISPLAY UNIT : Diagnosis Procedure".
Is inspection result OK?
YES >> GO TO 2
NO >> Repair malfunctioning parts.
2.CHECK CONTINUITY CO MMUNICATION CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect display unit connector M93 and AV control unit connector M43.
3. Check continuity between display unit harness connector M93 (A) terminals 11, 22 and AV control unit harness connector M43
(B) terminals 30, 31.
4. Check continuity between display unit harness connector M93 (A) terminals 11, 22 and ground.
Are continuity results as specified?
YES >> GO TO 3
NO >> Repair harness or connector.
Part name Description
DISPLAY UNIT • Display image is controlled by the serial communication from AV control unit.
• RGB image signal is input from AV control unit (RGB, RGB area and RGB syn-
chronizing). Auxiliary image signal is input from the auxiliary input jack. Cam-
era image signal is input from the camera control unit.
• Synchronize signal (HP, VP) is output to AV control unit.
• Touch panel function can be operated for each system by touching a display directly.
DTC Display contents of
CONSULT-III DTC Detection Condit
ion Possible causes
U1243 FRONT DISP CONN
[U1243] • Display unit power supply and ground circuit malfunc-
tion is detected.
• Malfunction is detected on communication circuit be- tween display unit and AV control unit.
• Malfunction is detected on communication signal be-
tween display unit and AV control unit. • Display unit power supply and
ground circuit.
• Communication circuit between display unit and AV control unit.
AB Continuity
Connector Terminal Connector Terminal
M93 11
M43 30
Ye s
22 31
A —Con tin uit y
Connector Terminal
M93 11
Ground No
22
ALNIA0397GB
Revision: March 2010 2008 QX56

AV-56
< COMPONENT DIAGNOSIS >[AUDIO SYSTEM]
U1243 DISPLAY UNIT
3.CHECK COMMUNICATION SIGNAL
1. Connect display unit connector M93 and AV control unit connec- tor M43.
2. Turn ignition switch ON.
3. Check signal between display unit harness connector M93 ter- minal 11 and ground.
Are voltage readings as specified?
YES >> GO TO 4
NO >> Replace AV control unit. Refer to AV-164, "
Removal and Installation".
4.CHECK COMMUNICATION SIGNAL
Check signal between display unit harness connector M93 terminal
22 and ground.
Are voltage readings as specified?
YES >> Inspection end.
NO >> Replace display unit. Refer to AV-166, "
Removal and Installation".
ConnectorTe r m i n a l s
Reference Signal
(+) (-)
M93 11 Ground
ALNIA0398GB
PKIB5039J
Connector Te r m i n a l s
Reference Signal
(+) (-)
M93 22 Ground
ALNIA0399GB
PKIB5039J
Revision: March 2010 2008 QX56

AV
U1244 GPS ANTENNAAV-57
< COMPONENT DIAGNOSIS > [AUDIO SYSTEM]
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U1244 GPS ANTENNA
DescriptionINFOID:0000000001696085
Refer to AV-13, "System Description".
DTC LogicINFOID:0000000001696086
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000001696087
1.GPS ANTENNA CHECK
Inspect GPS antenna and antenna feeder for damage or poor connection.
Is the GPS antenna and feeder clean and undamaged?
YES >> GO TO 2
NO >> Repair or replace malfunctioning parts.
2.CHECK AV CONTROL UNIT VOLTAGE
1. Turn ignition switch ON.
2. Check voltage between AV control unit connector M124 terminal 116 and ground.
Is the voltage reading as specified?
YES >> Replace GPS antenna. Refer to AV-181, "Removal and
Installation".
NO >> Replace AV control unit. Refer to AV-164, "
Removal and
Installation".
DTC CONSULT-III display Detection condition
U1244 GPS ANTENNA CONN
[U1244]
GPS antenna connection malfunction is detected.
116 - Ground
: Approx. 5V
ALNIA0400GB
Revision: March 2010 2008 QX56