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HAC-56
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BLOWER MOTOR CONTROL SYSTEM
Check continuity between terminals by supplying 12 volts and
ground to coil side terminals of relay.
Front Blower Motor
Confirm smooth rotation of the blower motor.
• Ensure that there are no foreign particles inside the blower unit.
• Apply 12 volts to terminal 2 and ground to terminal 1 and verify that
the motor operates freely and quietly.
Rear Blower Motor DescriptionINFOID:0000000003775360
SYSTEM DESCRIPTION
Component Parts
Rear blower speed control system components are:
• A/C auto amp.
• A/C and AV switch assembly
• Rear air control (front)
• Rear air control (rear)
• Variable blower control (rear)
• Rear blower motor
• Rear blower motor relay
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System Operation
Rear Blower Control
When the rear blower control dial (front) R INFINITI QX56 2009 Factory Service Manual BLOWER MOTOR CONTROL SYSTEMHAC-57
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System Operation
Rear Blower Control
When the rear blower control dial (front) R](/manual-img/42/57031/w960_57031-2369.png)
BLOWER MOTOR CONTROL SYSTEMHAC-57
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System Operation
Rear Blower Control
When the rear blower control dial (front) REAR CTRL s
witch is pressed (indicator on), it allows the rear air
control (rear) to control the rear blower motor speed. If t he REAR CTRL switch is off (indicator off), the rear air
control (front) controls the rear blower motor speed regardless of the rear air control (rear) position.
Rear Blower Motor Co mponent Function CheckINFOID:0000000003775361
INSPECTION FLOW
SYMPTOM:
• Rear blower motor does not operate from the rear air control (front) and the rear air control (rear).
• Rear blower motor operates from rear air control (front) only.
• Rear blower motor operates in high at all times.
INSPECTION FLOW
1.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 2.
2.CONFIRM SYMPTOM BY PERFORMING REAR BL OWER MOTOR OPERATIONAL CHECK FROM REAR
AIR CONTROL (FRONT)
1. Turn ignition switch ON.
2. Turn the rear air control (front) blower control dial to the lowest speed and check for rear blower operation
(REAR CTRL indicator off).
3. Continue checking that rear blower speed increases as the rear blower control dial is rotated clockwise.
Does the rear blower motor operate correctly?
YES >> GO TO 3.
NO >> Check the rear blower motor operation. Refer to HAC-57, "
Rear Blower Motor Component Func-
tion Check".
3.CONFIRM SYMPTOM BY PERFORMING REAR BLOWER MOTOR OPERATIONAL CHECK FROM
REAR AIR CONTROL (REAR)
1. Press the REAR CTRL switch (indicator on) on the rear air control (front) to send control of the rear blower motor back the rear air control (rear).
2. Turn the rear air control (rear) blower control dial to the lowest speed and check for rear blower operation.
3. Continue checking that rear blower speed increases as the rear blower control dial is rotated clockwise.
Does the rear blower motor operate correctly?
YES >> GO TO 4.
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BLOWER MOTOR CONTROL SYSTEM
NO >> • Check the rear air control (rear). Refer to
HAC-59, "Rear Air Control (Rear) Diagnosis Proce-
dure #2". INFINITI QX56 2009 Factory Service Manual HAC-58
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BLOWER MOTOR CONTROL SYSTEM
NO >> • Check the rear air control (rear). Refer to
HAC-59, "Rear Air Control (Rear) Diagnosis Proce-
dure #2".](/manual-img/42/57031/w960_57031-2370.png)
HAC-58
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
NO >> • Check the rear air control (rear). Refer to
HAC-59, "Rear Air Control (Rear) Diagnosis Proce-
dure #2".
4.RECHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-5, "
Operational Check (Rear)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> Inspection End.
Rear Air Control (Front) Diagnosis Procedure #1INFOID:0000000003775362
REAR BLOWER MOTOR INOPERATIVE/ON AT ALL TIMES.
1.CHECK FUSES
Check 10A fuse [No. 19 (Located in the fuse block J/B)].
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 6.
2.CHECK REAR AIR CONTRO L (FRONT) POWER SUPPLY
1. Disconnect rear air control (front) harness connector.
2. Turn ignition switch ON.
3. Check voltage between rear air control (front) harness connec- tor R108 terminal 1 and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair harness or connector.
3.CHECK REAR AIR CONTROL (FRONT) LIN BUS VOLTAGE
Check voltage between rear air control (front) harness connector
R108 terminal 5 and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair harness or connector.
4.CHECK REAR AIR CONTRO L (FRONT) GROUND CIRCUIT
Fuse is good.
Battery voltage should exist.
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Battery voltage should exist.
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1. Turn ignition switch OFF.
2. Check continuity between rear air control (front INFINITI QX56 2009 Factory Service Manual BLOWER MOTOR CONTROL SYSTEMHAC-59
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1. Turn ignition switch OFF.
2. Check continuity between rear air control (front](/manual-img/42/57031/w960_57031-2371.png)
BLOWER MOTOR CONTROL SYSTEMHAC-59
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1. Turn ignition switch OFF.
2. Check continuity between rear air control (front) harness con- nector R108 terminal 6 and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair harness or connector.
5.CHECK REAR AIR CONTROL (FRO NT) LIN BUS CIRCUIT FOR OPEN
1. Disconnect A/C auto amp. connector.
2. Check continuity between A/C auto amp. harness connector M50 (A) terminal 48 and rear air control (front) harness connec-
tor R108 (B) terminal 5.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair harness or connector.
6.REPLACE FUSE
1. Replace fuse.
2. Activate the rear blower motor.
Does the fuse blow?
YES >> GO TO 7.
NO >> Inspection End.
7.CHECK REAR AIR CONTROL (FRONT) POWER SUPPLY CIRCUIT FOR SHORT
1. Turn ignition switch OFF.
2. Disconnect rear air control (front), (rear), and A/C auto amp. connectors.
3. Check continuity between rear air control (front) harness con- nector R108 terminal 1 and ground.
Is the inspection result normal?
YES >> Repair harness or connector for a short.
NO >> System OK.
Rear Air Control (Rea r) Diagnosis Procedure #2INFOID:0000000003775363
REAR AIR CONTROL (REAR) INOPERATIVE
1.CHECK REAR AIR CONTROL (REAR) POWER SUPPLYContinuity should exist.
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Continuity should exist.
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1 - Ground
: Continuity should not exist.
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< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
1. Disconnect rear air control (rear) harness connector.
2. Turn ignition switch ON.
3. Check voltage between rear INFINITI QX56 2009 Factory Service Manual HAC-60
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BLOWER MOTOR CONTROL SYSTEM
1. Disconnect rear air control (rear) harness connector.
2. Turn ignition switch ON.
3. Check voltage between rear](/manual-img/42/57031/w960_57031-2372.png)
HAC-60
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BLOWER MOTOR CONTROL SYSTEM
1. Disconnect rear air control (rear) harness connector.
2. Turn ignition switch ON.
3. Check voltage between rear air control (rear) harness connector
R209 terminal 1 and ground.
Is the inspection results normal?
YES >> GO TO 2.
NO >> Repair harness or connector.
2.CHECK REAR AIR CONTROL (REAR) LIN BUS CIRCUIT
Check voltage between rear air control (rear) harness connector
R209 terminal 5 and ground.
Is the inspection results normal?
YES >> GO TO 3.
NO >> GO TO 4.
3.CHECK REAR AIR CONTROL (REAR) GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between rear air control (rear) harness connec- tor R209 terminal 6 and ground.
Is the inspection results normal?
YES >> GO TO 4.
NO >> Repair harness or connector.
4.CHECK REAR AIR CONTROL (REA R) LIN BUS CIRCUIT FOR OPEN
1. Disconnect A/C auto amp. connector.
2. Check continuity between A/C auto amp. harness connector M50 (A) terminal 47 and rear air control (rear) harness connec-
tor R209 (B) terminal 5.
Is the inspection results normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair harness or connector.
Rear Blower Motor Component Inspection INFOID:0000000003775364
COMPONENT INSPECTION
Rear Blower Motor Relay
Battery voltage should exist.
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Battery voltage should exist.
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Continuity should exist.
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Continuity should exist.
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BLOWER MOTOR CONTROL SYSTEMHAC-61
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Check circuit continuity between terminals by supplying 12 volts and
ground to coil side terminals of relays.
Rear Blower Motor
Check that there are no foreign particles inside the intake unit.
Apply 12 volts to terminal 2 and ground to terminal 1 and ensure that
the blower motor rotates freely and quietly.
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< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
REAR AIR CONTROL SYSTEM
Rear Air Control System DescriptionINFOID:0000000003775365
SYSTEM DESCRIPTION
Component Parts
INFINITI QX56 2009 Factory Service Manual HAC-62
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REAR AIR CONTROL SYSTEM
REAR AIR CONTROL SYSTEM
Rear Air Control System DescriptionINFOID:0000000003775365
SYSTEM DESCRIPTION
Component Parts](/manual-img/42/57031/w960_57031-2374.png)
HAC-62
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
REAR AIR CONTROL SYSTEM
Rear Air Control System DescriptionINFOID:0000000003775365
SYSTEM DESCRIPTION
Component Parts
Rear air control sy
stem components are:
• A/C auto amp.
• Rear air control (front)
• Rear air control (rear)
• Air mix door motor (rear)
• Mode door motor (rear)
System Operation
Rear Air Control
When the REAR CTRL indicator is off the rear air cont rol (front) will control all rear blower motor speeds and
the rear temperature and mode operations. When the REAR CTRL switch is pressed (indicator on), the rear
air control (rear) will control all the rear blower mo tor speeds and the rear temperature and mode operations.
Rear Air Control Component Function CheckINFOID:0000000003775366
SYMPTOM:
• Temperature cannot be adjusted from the rear air controls.
• Mode cannot be adjusted from the rear air controls.
INSPECTION FLOW
1.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 2.
2.CONFIRM SYMPTOM BY PERFORMING REAR AIR CO NTROL (FRONT) AIR MIX DOOR MOTOR OP-
ERATIONAL CHECK
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2. Turn the rear blower motor to m INFINITI QX56 2009 Factory Service Manual REAR AIR CONTROL SYSTEMHAC-63
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1. Start and run engine to operating temperature.
2. Turn the rear blower motor to m](/manual-img/42/57031/w960_57031-2375.png)
REAR AIR CONTROL SYSTEMHAC-63
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1. Start and run engine to operating temperature.
2. Turn the rear blower motor to maximum speed from the rear air control (front).
3. Turn rear air control (front) temperature contro l dial clockwise and then counterclockwise (REAR CTRL
indicator off).
4. Check for hot air at rear discharge air outlets in the maximum heat position and cold air at discharge air outlets in the maximum cold position.
Does the rear air control (front) operate properly?
YES >> GO TO 3.
NO >> Check rear air control (front). Refer to HAC-63, "
Air Mix Door Motor (Rear) Diagnosis Procedure".
3.CONFIRM SYMPTOM BY PERFORMING REAR AIR CONTROL (REAR) AIR MIX DOOR MOTOR OPER-
ATIONAL CHECK
1. Press the REAR CTRL switch on rear air control (front) to send control to t he rear air control (rear).
2. Turn rear air control (rear) temperature control dial slowly clockwise and then counterclockwise (REAR
CTRL indicator on).
3. Check for hot air at rear discharge air outlets in the maximum heat position and cold air at rear discharge
air outlets in the maximum cold position.
Does the rear air control (rear) operate properly?
YES >> GO TO 4.
NO >> Check rear air control (rear). Refer to HAC-59, "
Rear Air Control (Rear) Diagnosis Procedure #2".
4.CONFIRM SYMPTOM BY PERFORMING REAR AIR CONTROL (FRONT) MODE OPERATIONAL CHECK
1. Press the REAR CTRL switch on rear air control (front) (REAR CTRL indicator off).
2. Press each mode switch and check for proper air discharge at the appropriate locations.
Does the rear air control (front) operate properly?
YES >> GO TO 5.
NO >> Check mode door motor (rear). Refer to HAC-67, "
Mode Door Motor (Rear) Diagnosis Proce-
dure".
5.CONFIRM SYMPTOM BY PERFORMING REAR AIR CONTROL (REAR) MODE OPERATIONAL CHECK
1. Press the REAR CTRL switch on rear air control (front) to send control to t he rear air control (rear).
2. Press each mode switch and check for proper air discharge at the appropriate locations.
Does the rear air control (rear) operate properly?
YES >> System OK.
NO >> Replace rear air control (rear). Refer to VTL-7, "
Removal and Installation".
Air Mix Door Motor (Rear) Diagnosis ProcedureINFOID:0000000003775367
DIAGNOSTIC PROCEDURE FOR INOPERATIVE AIR MIX DOOR MOTOR (REAR)
SYMPTOM:
• Temperature control (rear) operation is malfunctioning.
1.CHECK REAR AIR CONTROL (FRONT) POWER SUPPLY
1. Disconnect rear air control (front) harness connector.
2. Turn ignition switch ON.
3. Check voltage between rear air control (front) harness connec- tor R108 terminal 1 and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair harness or connector.
2.CHECK REAR AIR CONTROL (FRONT) LIN BUS VOLTAGE Battery voltage should exist.
AWIIA0182ZZ
Revision: December 20092009 QX56