INFINITI QX56 2008 Factory Service Manual

HAC-68
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector
M50 terminal 43 and terminal 44.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> GO TO 7.
7.CHECK MODE DOOR MOTOR CIRCUITS FOR SHORT TO GROUND
1. Disconnect the A/C auto amp. harness connector and mode door motor (rear) harness connector
2. Check continuity between A/C auto amp. harness connector
M50 terminal 43, 44 and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair or replace harness as necessary.
8.CHECK MODE DOOR MOTOR CIRCUITS FOR OPEN
Check continuity between A/C auto amp. harness connector M50 (A)
terminal 43, 44 and the mode door motor (rear) harness connector
B156 (B) terminal 5, 6.
Is the inspection result normal?
YES >> Replace mode door motor. Refer to VTL-26, "Removal
and Installation".
NO >> Repair or replace harness as necessary.
9.CHECK A/C AUTO AMP. POWER AND GROUND FOR MODE DOOR MOTOR (REAR)
Check voltage between A/C auto amp. harness connector M50 ter-
minal 43 and terminal 44 while pressing the mode switch to the
FLOOR ( ) mode.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
10.CHECK A/C AUTO AMP. FOR MODE DOOR MOTOR (REAR) PBR POWER AND GROUND
Continuity should exist.
AWIIA0190ZZ
43 - Ground
: Continuity should not exist.
44 - Ground : Continuity should not exist.
AWIIA0192ZZ
5 - 43 : Continuity should exist.
6 - 44 : Continuity should exist.
AWIIA0191ZZ
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M50 44 43 Press
mode
switch (rear) Battery
voltage
AWIIA0196ZZ
Revision: March 2010 2008 QX56

REAR AIR CONTROL SYSTEMHAC-69
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Check voltage between A/C auto am p. harness connector M50 (A)
terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 14.
NO >> GO TO 11.
11 .CHECK PBR REFERENCE VO LTAGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 12
12.CHECK PBR REFERENCE VO LTAGE CIRCUIT FOR OPEN
1. Disconnect the mode door motor (rear) harness connector.
2. Check continuity between mode door motor (rear) harness con- nector B156 (B) terminal 3, 1 and A/C auto amp. harness con-
nector M49 (C) terminal 3, M50 (A) terminal 28.
Is the inspection result normal?
YES >> Replace mode door motor (rear). Refer to VTL-26,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
13.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 terminal 28 and ground.
Is the inspection result normal?
YES >> Replace the A/C auto amp. Refer to VTL-7, "Removal
and Installation".
NO >> Repair or replace harness as necessary.
14.CHECK PBR FEEDBACK VOLTAGE
Connector Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
A/C auto amp.: M49, M50 28 35V
AWIIA0099ZZ
Continuity should exist.
AWIIA0101ZZ
28 - 1 : Continuity should exist.
3 - 3 : Continuity should exist.
AWIIA0102ZZ
Continuity should not exist.
AWIIA0100ZZ
Revision: March 2010 2008 QX56

HAC-70
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
Check voltage between A/C auto amp. harness connector M50 ter-
minal 30 and ground while cycling mode switch through all modes.
Is the inspection result normal?
YES >> System OK.
NO >> GO TO 15.
15.CHECK PBR FEEDBACK CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the mode door motor harness connector and A/C auto amp. harness connector.
3. Check continuity between mode door motor harness connector B156 (B) terminal 2 and A/C auto amp. harness connector M50
(A) terminal 30.
Is the inspection result normal?
YES >> GO TO 16.
NO >> Repair or replace harness as necessary.
16.CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR SHORT TO GROUND
Check continuity between A/C auto amp. harness connector M50
terminal 30 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary. Voltage
: Approx. 1V - 4.5V
AWIIA0194ZZ
Continuity should exist.
AWIIA0195ZZ
Continuity should not exist.
AWIIA0193ZZ
Revision: March 2010 2008 QX56

MAGNET CLUTCHHAC-71
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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MAGNET CLUTCH
System DescriptionINFOID:0000000001679808
SYSTEM DESCRIPTION
The A/C auto amp. controls compressor operation based on ambient and intake temperature and a signal
from ECM.
Low Temperature Protection Control
The A/C auto amp. will turn the compressor ON or OFF as determined by a signal detected by the intake sen-
sor and the ambient sensor.
When intake air temperature is higher than the preset value, the compressor turns ON. The compressor turns
OFF when intake air temperature is lower than the pres et value. That preset value is dependent on the ambi-
ent temperature, refer to the following table.
Magnet Clutch Componen t Function CheckINFOID:0000000001679809
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL CHECK - MAGNET CLUTCH
1. Turn ignition switch ON.
2. Press the A/C switch.
3. Press vent switch ( ).
4. Display shows , A/C. Confirm that the compress or clutch engages (sound or visual inspection). (Dis-
charge air and blower speed will depend on ambient, in-vehicle and set temperatures.)
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 5.
5.CHECK AMBIENT SENSOR
Check and verify ambient s ensor circuit. Refer to HAC-78, "
Ambient Sensor Diagnosis Procedure".
Ambient temperature ° C (°F) Compressor ON intake temperature °C ( °F) Compressor OFF intake temperature °C ( °F)
0 (32) 5.5 (42) 5.0 (41)
10 (50) 5.5 (42) 5.0 (41)
20 (68) 5.5 (42) 5.0 (41)
30 (86) 4.0 (39) 3.5 (38)
40 (104) 3.5 (38) 3.0 (37)
50 (122) 3.5 (38) 3.0 (37)
Revision: March 2010 2008 QX56

HAC-72
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MAGNET CLUTCH
>> GO TO 6.
6.CHECK INTAKE SENSOR
Check and verify intake sensor circuit. Refer to HAC-86, "
Intake Sensor Diagnosis Procedure".
>> GO TO 7.
7.RECHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)" .
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair" .
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
Magnet Clutch Diagnosis ProcedureINFOID:0000000001679810
DIAGNOSTIC PROCEDURE FOR MAGNET CLUTCH
SYMPTOM: Magnet clutch does not engage when A/C switch is ON.
1.CHECK INTAKE AND AMBI ENT SENSOR CIRCUITS
Check intake and ambient sensors. Refer to HAC-22, "
A/C and AV Switch Assembly Self-Diagnosis".
Is the inspection result normal?
YES >> GO TO 2.
NO >> • Malfunctioning intake sensor. Refer to HAC-86, "
Intake Sensor Diagnosis Procedure".
• Malfunctioning ambient sensor. Refer to HAC-78, "
Ambient Sensor Diagnosis Procedure".
2.PERFORM AUTO ACTIVE TEST
Refer to PCS-14, "
CONSULT - III Function (IPDM E/R)".
Does magnet clutch operate?
YES >> • WITH CONSULT-III GO TO 5.
• WITHOUT CONSULT-III GO TO 6.
AWIIA0198GB
Revision: March 2010 2008 QX56

MAGNET CLUTCHHAC-73
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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NO >> Check 10A fuse (No. 42, located in IPDM E/R), and GO TO 3.
3.CHECK CIRCUIT CONTINUITY BETW EEN IPDM E/R AND COMPRESSOR
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector and compressor (magnet clutch) connector.
3. Check continuity between IPDM E/R harness connector E119
terminal 11 and A/C compressor harness connector F3 terminal
1.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair harness or connector.
4.CHECK MAGNET CLUTCH CIRCUIT
Check for operation sound when applying battery voltage direct cur-
rent to terminal.
Is the inspection result normal?
YES >> Replace IPDM E/R. Refer to PCS-34, "Removal and
Installation of IPDM E/R".
NO >> Replace magnet clutch. Refer to HA-32, "
Removal and
Installation for Compressor Clutch".
5.CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal. Refer to HAC-20, "
CONSULT-III Function (HVAC)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 6.
6.CHECK CIRCUIT CONTINUITY BETWEEN BCM AND A/C AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect BCM connector and A/C auto amp. connector.
3. Check continuity between BCM harness connector M18 (A) ter- minal 27 and A/C auto amp. harness connector M49 (B) terminal
4.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair harness or connector.
7.CHECK VOLTAGE FOR A/C AUTO AMP. (A/C COMPRESSOR ON SIGNAL)
11 – 1
: Continuity should exist.
WJIA0560E
SJIA0197E
A/C SW ON: COMP ON SIG ON
A/C SW OFF : COMP ON SIG OFF
27 - 4 Continuity should exist.
AWIIA0199ZZ
Revision: March 2010 2008 QX56

HAC-74
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MAGNET CLUTCH
1. Reconnect BCM connector and A/C auto amp. connector.
2. Turn ignition switch ON.
3. Check voltage between A/C auto amp. harness connector M49
terminal 4 and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO-1 >> If the voltage is approx. 5V when A/C switch is ON, replace A/C auto amp. Refer to VTL-7,
"Removal and Installation".
NO-2 >> If the voltage is approx. 0V when A/C switch is OFF, replace BCM. Refer to BCS-55, "
Removal
and Installation".
8.CHECK REFRIGERANT PRESSURE SENSOR
1. Start engine.
2. Check voltage between ECM harness connector F54 terminal 70 and ground.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Refer to EC-423, "
Diagnosis Procedure".
9.CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to HAC-20, "
CONSULT-III Function (HVAC)".
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 10.
10.CHECK CIRCUIT CONTINUITY BETW EEN BCM AND A/C AUTO AMP.
Te r m i n a l s
Condition Voltage
(+)
(-)
A/C auto
amp. con-
nector Te r m i n a l N o .
M49 4 Ground A/C switch: ON Approx. 0V
A/C switch: OFF Approx. 5V
AWIIA0200ZZ
Te r m i n a l s
ConditionVoltage
(+)
(-)
ECM con-
nector Te r m i n a l N o .
F54 70 Ground A/C switch: ON Approx. 0.36 - 3.88V
LJIA0124E
FRONT BLOWER CONTROL
DIAL ON : FAN ON SIG ON
FRONT BLOWER CONTROL
DIAL OFF : FAN ON SIG OFF
Revision: March 2010
2008 QX56

MAGNET CLUTCHHAC-75
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Turn ignition switch OFF.
2. Disconnect BCM connector and A/C auto amp. connector.
3. Check continuity between BCM harness connector M18 (A) ter- minal (A) 28 and A/C auto amp. harness connector M49 (B) ter-
minal 5.
Is the inspection result normal?
YES >> GO TO 11.
NO >> Repair harness or connector.
11 .CHECK VOLTAGE FOR A/C AUTO AMP. (FAN ON SIGNAL)
1. Reconnect BCM connector and A/C auto amp. connector.
2. Turn ignition switch ON.
3. Check voltage between A/C auto amp. harness connector M49 terminal 5 and ground.
Is the inspection result normal?
YES >> GO TO 12.
NO-1 >> If the voltage is approx. 5V when blower motor is ON, replace A/C auto amp. Refer to VTL-7,
"Removal and Installation".
NO-2 >> If the voltage is approx. 0V when blower motor is OFF, replace BCM. Refer to BCS-55, "
Removal
and Installation".
12.CHECK CAN COMMUNICATION
Check CAN communication. Refer to LAN-4, "
System Description".
•BCM – ECM
• ECM – IPDM E/R
• ECM – A/C auto amp.
Is the inspection result normal?
YES >> Inspection End.
NO >> Repair or replace malfunctioning part(s). 28 - 5
Continuity should exist.
AWIIA0201ZZ
Te r m i n a l s
Condition Voltage
(+)
(-)
A/C auto amp.
connector Te r m i n a l N o .
M49 5GroundA/C switch: ON
Blower motor
operates
Approx. 0V
A/C switch: OFF Approx. 5V
AWIIA0202ZZ
Revision: March 2010 2008 QX56

HAC-76
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
WATER VALVE CIRCUIT
WATER VALVE CIRCUIT
DescriptionINFOID:0000000001679811
COMPONENT DESCRIPTION
Water Valve
The water valve (1) cuts the flow of engine coolant to the front and
rear heater cores to allow for maximum cooling during A/C opera-
tion. It is controlled by the A/C auto amp.
Water Valve Diagnosis ProcedureINFOID:0000000001679812
DIAGNOSTIC PROCEDURE FOR WATER VALVE
1.CHECK WATER VALVE POWER AND GROUND CIRCUITS
1. Disconnect water valve connector F68.
2. Turn ignition switch ON.
3. Rotate temperature control dial (driver) to 32 °C (90° F).
4. Check voltage between water valve harness connector F68 ter- minal 1 and terminal 2 while rotating temperature control dial
(driver) to 18 °C (60° F).
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector M50.
3. Check continuity between water valve harness connector F68 (A) terminal 2 and A/C auto amp. harness connector M50 (B)
terminal 46.
4. Check continuity between water valve harness connector F68 (A) terminal 2 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and Installation".
NO >> Repair harness or connector.
3.CHECK WATER VALVE POWER AND GROUND CIRCUITS
WJIA1791E
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Water valve: F68 2 1Rotate temperature
control dial Battery
voltage
WJIA1794E
2 - 46 : Continuity should exist.
2 - Ground : Continuity should not exist.
AWIIA0203ZZ
Revision: March 2010 2008 QX56

WATER VALVE CIRCUITHAC-77
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Rotate temperature control dial (driver) to 18 °C (60 °F).
2. Check voltage between water valve harness connector F68 ter- minal 1 and terminal 2 while rotating temperature control dial
(driver) to 32 °C (90° F).
Is the inspection result normal?
YES >> Replace the water valve.
NO >> GO TO 4.
4.CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector M50.
3. Check continuity between water valve harness connector F68 (A) terminal 1 and A/C auto amp. harness connector M50 (B)
terminal 45.
4. Check continuity between water valve harness connector F68 (A) terminal 1 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and Installation".
NO >> Repair harness or connector.
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Water valve: F68 1 2Rotate temperature
control dial Battery
voltage
WJIA1792E
1 - 45 : Continuity should exist.
1 - Ground : Continuity should not exist.
AWIIA0204ZZ
Revision: March 2010 2008 QX56