2010 INFINITI QX56 Ignition switch

HAC-66
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
Check voltage between A/C auto amp. 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 VOLTAGE 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 VOLTAGE 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-31,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
13.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
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.
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: April 20092010 QX56

REAR AIR CONTROL SYSTEMHAC-67
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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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: April 20092010 QX56

HAC-68
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MAGNET CLUTCH
MAGNET CLUTCH
System DescriptionINFOID:0000000005147713
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 O FF as determined by a signal detected by the intake sen-
sor and the ambient sensor.
When intake air temperature is higher than the preset va lue, 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 Com ponent Function CheckINFOID:0000000005147714
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OP ERATIONAL 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 ambi ent, in-vehicle and set temperatures.)
Is the inspection result normal?
YES >> Inspection End.
NO >> Go to diagnosis procedure. Refer to HAC-68, "
Magnet Clutch Diagnosis Procedure".
Magnet Clutch Diagnosis ProcedureINFOID:0000000005147715
Regarding Wiring Diagram information, refer to HAC-91, "Wiring Diagram".
DIAGNOSTIC PROCEDURE FOR MAGNET CLUTCH
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: April 20092010 QX56

MAGNET CLUTCHHAC-69
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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SYMPTOM: Magnet clutch does not engage when A/C switch is ON.
1.CHECK INTAKE AND AMBIENT SENSOR CIRCUITS
Check intake and ambient sensors. Refer to HAC-23, "
A/C and AV Switch Assembly Self-Diagnosis".
Is the inspection result normal?
YES >> GO TO 2.
NO >> • Malfunctioning intake sensor. Refer to HAC-83, "
Intake Sensor Diagnosis Procedure".
• Malfunctioning ambient sensor. Refer to HAC-75, "
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.
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
AWIIA1070GB
11 – 1 : Continuity should exist.
WJIA0560E
Revision: April 20092010 QX56

HAC-70
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MAGNET CLUTCH
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-35, "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 BETW EEN 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)
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-59, "
Removal
and Installation".
8.CHECK REFRIGERANT PRESSURE SENSOR
1. Start engine.
SJIA0197E
A/C SW ON : COMP ON SIG ON
A/C SW OFF : COMP ON SIG OFF
27 - 4 Continuity should exist.
AWIIA0199ZZ
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
Revision: April 20092010 QX56

MAGNET CLUTCHHAC-71
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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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-419, "
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.
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 28 and A/C auto amp. harness connector M49 (B) terminal
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".
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
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: April 20092010 QX56

WATER VALVE CIRCUITHAC-73
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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WATER VALVE CIRCUIT
DescriptionINFOID:0000000005147716
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:0000000005147717
Regarding Wiring Diagram information, refer to HAC-91, "Wiring Diagram".
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 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.
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: April 20092010 QX56

HAC-74
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
WATER VALVE CIRCUIT
3.CHECK WATER VALVE POWER AND GROUND CIRCUITS
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: April 20092010 QX56