2008 INFINITI QX56 phone

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
POWER SUPPLY AND GROUND CIRCUITAV-71
< COMPONENT DIAGNOSIS > [AUDIO SYSTEM]
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1. Turn ignition switch OFF.
2. Disconnect video monitor connector.
3. Check continuity between video monitor harness connector R202 and ground.
Does continuity exist?
YES >> Inspection end.
NO >> Repair harness or connector.
MICROPHONE
MICROPHONE : Diagnosis ProcedureINFOID:0000000001696106
1.CHECK POWER SUPPLY CIRCUIT
Check voltage between microphone harness connector R109 termi-
nal 4 and ground.
Is approximately 5V present?
YES >> GO TO 3
NO >> GO TO 2
2.CHECK POWER SUPPLY CIRCUIT (CONTINUITY)
1. Turn ignition switch OFF.
2. Disconnect microphone and AV control unit harness connectors.
3. Check continuity between microphone harness connector R109 (A) terminal 4 and AV control unit harness connector M45 (B)
terminal 70.
4. Check continuity between microphone harness connector R109 (A) terminal 4 and ground.
Are the continuity test results as specified?
YES >> Replace the AV control unit. Refer to AV-164, "Removal and Installation".
NO >> Repair harness or connector.
3.CHECK GROUND CIRCUIT
Connector No. Terminal No. Ignition switch position Continuity
R202 1
OFF Yes
2
ALNIA0329GB
Signal name Connector
No. Te r m i n a l N o . Ignition
switch posi- tion Value (Ap-
prox.)
MIC power R109 4ON 5V
WKIA5796E
AB
Continuity
Connector Terminal Connector Terminal
R109 4 M45 70 Yes
A —Con tin uit y
Connector Terminal
R109 4Ground No
ALNIA0441GB
Revision: March 2010 2008 QX56

AV-72
< COMPONENT DIAGNOSIS >[AUDIO SYSTEM]
POWER SUPPLY AND GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect microphone harness connector R109 and AV control
unit harness connector M45.
3. Check continuity between microphone harness connector R109 (A) terminal 2 and AV control unit harness connector M45 (B)
terminal 71.
Does continuity exist?
YES >> Inspection End.
NO >> Repair harness or connector.
AB Continuity
Connector Terminal Connector Terminal
R109 2 M45 71 Yes
ALNIA0408GB
Revision: March 2010 2008 QX56

AV
STEERING SWITCHAV-101
< COMPONENT DIAGNOSIS > [AUDIO SYSTEM]
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STEERING SWITCH
DescriptionINFOID:0000000001696137
When one of the steering wheel audio control switches is pushed, the resistance in the steering wheel audio
control switch circuit changes depending on which button is pushed.
Diagnosis ProcedureINFOID:0000000001696138
1.CHECK STEERING WHEEL AUDI O CONTROL SWITCH RESISTANCE
1. Turn ignition switch OFF.
2. Disconnect steering wheel audio control switch connector M102.
3. Check resistance between steering switch connector terminals.
Do the steering wheel audio control switches check OK?
YES >> GO TO 2
NO >> Replace steering wheel audio control switch. Refer to AV-174, "
Removal and Installation".
2.CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect AV control unit connector M42 and spiral cable con- nector M30.
3. Check continuity between AV control unit harness connector M42 (A) and spiral cable harness connector M30 (B).
4. Check continuity between AV control unit connector M42 (A) and ground.
Are the continuity results as specified?
YES >> GO TO 3
NO >> Repair harness.
Terminal Signal name Condition Resistance
(Ω )
(Approx.)
16 17 Seek (down)
Depress switch. 165
Volume (down) Depress VOL down switch. 652
Phone/End Depress switch. 0
20 17 Seek (up)
Depress switch. 165
Volume (up) Depress VOL up switch. 652
Phone/Send Depress switch. 0
WKIA4457E
AB
Continuity
Connector Terminal Connector Terminal
M42 6
M30 24
Ye s
15 31
16 32
A —Continuity
Connector Terminal
M42 6
Ground No
15
16
ALNIA0332GB

AV
MICROPHONE SIGNAL CIRCUITAV-103
< COMPONENT DIAGNOSIS > [AUDIO SYSTEM]
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MICROPHONE SIGNAL CIRCUIT
DescriptionINFOID:0000000001696139
Voice signals are transmitted from the microphone to the AV control unit using the microphone signal circuits.
Diagnosis ProcedureINFOID:0000000001696140
1.CHECK HARNESS BETWEEN AV CONTROL UNIT AND MICROPHONE
1. Turn ignition switch OFF.
2. Disconnect AV control unit connector and microphone connec- tor.
3. Check continuity between AV control unit harness connector M45 (A) and microphone harness connector R109 (B).
4. Check continuity between AV control unit harness connector M45 (A) and ground.
Are the continuity test results as specified?
YES >> GO TO 2
NO >> Repair harness or connector.
2.CHECK MICROPHONE POWER SUPPLY
1. Connect AV control unit connector and microphone connector.
2. Turn ignition switch ON.
3. Check voltage between microphone harness connector R109 terminal 4 and ground.
Is voltage reading approx. 5 volts?
YES >> GO TO 3
NO >> Replace AV control unit. Refer to AV-164, "
Removal and
Installation".
3.CHECK MICROPHONE SIGNAL
AB
Continuity
Connector Terminal Connector Terminal
M45 72
R109 1
Ye s
71 2
70 4
A —Continuity
Connector Terminal
M45 70
GroundNo
71
72
ALNIA0422GB
4 - Ground : Approx. 5V
WKIA5796E
Revision: March 2010 2008 QX56