2009 INFINITI QX56 air condition

BLOWER MOTOR CONTROL SYSTEMHAC-53
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Check 20A fuses [No. 24 and 27 (Located in the fuse and fusible link box)]. For fuse layout. Refer to PG-72,
"Terminal Arrangement".
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 7.
2.CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front blower motor connector.
3. Turn ignition switch ON.
4. Press the A/C switch.
5. Press the front blower contro l "+" switch to maximum speed.
6. Check voltage between front blower motor harness connector
M62 terminal 2 and ground.
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 3.
3.CHECK FRONT BLOWER MOTOR RELAY (S WITCH SIDE) POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front blower motor relay.
3. Check voltage between front blower motor relay harness con- nector M107 terminal 5 and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair harness or connector.
4.CHECK FRONT BLOWER MOTOR RELAY
Turn ignition switch OFF.
Check front blower motor relay. Refer to HAC-55, "
Front Blower Motor Component Inspection".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace front blower motor relay.
5.CHECK FRONT BLOWER MOTOR RELA Y (SWITCH SIDE) CIRCUIT FOR OPEN
Check continuity between front bl ower motor relay harness connec-
tor M107 terminal 3 and front blower motor harness connector M62
terminal 2.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair harness or connector.
6.CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY Fuses are good.
2 - Ground
: Battery voltage
WJIA1331E
5 - Ground: Battery voltage
WJIA1886E
3 - 2 : Continuity should exist.
WJIA1360E
Revision: December 20092009 QX56

HAC-54
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
1. Turn ignition switch ON.
2. Check voltage between front blower motor relay harness con-
nector M107 terminal 2 and ground.
Is the inspection result normal?
YES >> Repair front blower motor ground circuit or connector.
NO >> Repair harness or connector.
7.REPLACE FUSES
Replace fuses.
Does the fuse blow?
YES >> • If fuse blows without activating the front blower motor, repair short between fuse and front blower motor relay.
• If fuse blows activating the front blower motor, GO TO 8.
NO >> Inspection End.
8.CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT
1. Turn ignition switch OFF.
2. Disconnect front blower motor connector, front blower motor relay and variable blower control connector.
3. Check continuity between variable blower control harness con- nector M122 terminal 4 and ground.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Repair harness or connector.
9.CHECK FRONT BLOWER MOTOR
Check front blower motor. Refer to HAC-55, "
Front Blower Motor Component Inspection".
Is the inspection result normal?
YES >> Replace variable blower control (front). Refer to VTL-29, "Removal and Installation".
NO >> Replace front blower motor. Refer to VTL-12, "
Removal and Installation".
10.CHECK FRONT BLOWER MOTOR
Check front blower motor. Refer to HAC-55, "
Front Blower Motor Component Inspection".
Is the inspection result normal?
YES >> GO TO 11.
NO >> Replace front blower motor. Refer to VTL-12, "
Removal and Installation".
11 .CHECK BLOWER MOTOR GROUND CIRCUIT
1. Disconnect variable blower control connector.
2. Check continuity between front blower motor harness connector M62 (B) terminal 1 and variable blower control harness connec-
tor M122 (A) terminal 2.
Is the inspection result normal?
YES >> GO TO 12.
NO >> Repair harness or connector. 2 - Ground
: Battery voltage
WJIA1363E
4 - Ground: Continuity should not exist.
AWIIA0177ZZ
1 - 2 : Continuity should exist.
AWIIA0179ZZ
Revision: December 20092009 QX56

BLOWER MOTOR CONTROL SYSTEMHAC-55
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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12.CHECK VARIABLE BLOWER CONTRO L POWER SUPPLY CIRCUIT FOR OPEN
1. Disconnect front blower motor relay.
2. Check continuity between front blower motor relay harness con- nector M107 (A) terminals 3 and variable blower control harness
connector M122 (B) terminal 4.
Is the inspection result normal?
YES >> GO TO 13.
NO >> Repair harness or connector.
13.CHECK VARIABLE BLOWER CONTROL GROUND CIRCUIT
Check continuity between variable blower control harness connector
M122 terminal 1 and ground.
Is the inspection result normal?
YES >> GO TO 14.
NO >> Repair harness or connector.
14.CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT
1. Reconnect all disconnected component connectors.
2. Disconnect A/C auto amp. connector.
3. Turn ignition switch ON.
4. Press the blower (+) switch to maximum speed.
5. Check voltage between A/C auto amp. harness connector M49 terminal 13 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> GO TO 15.
15.CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT FOR OPEN
1. Disconnect variable blower control connector.
2. Check continuity between A/C auto amp. harness connector M49 (B) terminal 13 and variable blower control harness con-
nector M122 (A) terminal 3.
Is the inspection result normal?
YES >> Replace variable blower control. Refer to VTL-29,
"Removal and Installation".
NO >> Repair harness or connector.
Front Blower Motor Component InspectionINFOID:0000000003775359
COMPONENT INSPECTION
3 - 4 : Continuity should exist.
AWIIA0175ZZ
1 - Ground: Continuity should exist.
AWIIA0180ZZ
13 - Ground : Approx. 4.5V
AWIIA1129ZZ
13 - 3: Continuity should exist.
AWIIA0178ZZ
Revision: December 20092009 QX56

HAC-56
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
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
WJIA1401E
WJIA1508E
Revision: December 20092009 QX56

BLOWER MOTOR CONTROL SYSTEMHAC-57
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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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.
AWIIA0181GB
Revision: December 20092009 QX56

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.
AWIIA0182ZZ
Battery voltage should exist.
AWIIA0183ZZ
Revision: December 20092009 QX56

BLOWER MOTOR CONTROL SYSTEMHAC-59
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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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.
AWIIA0184ZZ
Continuity should exist.
AWIIA0185ZZ
1 - Ground
: Continuity should not exist.
AWIIA0186ZZ
Revision: December 20092009 QX56

HAC-60
< 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 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.
AWIIA0182ZZ
Battery voltage should exist.
AWIIA0183ZZ
Continuity should exist.
AWIIA0184ZZ
Continuity should exist.
AWIIA0187ZZ
Revision: December 20092009 QX56