2010 INFINITI QX56 diagram

HAC-48
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
Blower Speed Compensation - Sunload
When the in-vehicle temperature and the set temperature
are very close, the blower will be operating at low
speed. The speed will vary depending on the sunload. During conditions of low or no sunload, the blower
operates at low speed. During high sunload conditions, the A/C auto amp. causes the blower speed to
increase.
Blower Speed Control Specification
COMPONENT DESCRIPTION
Variable Blower Control
The variable blower control is located on the cooling unit. The vari-
able blower control receives a gate voltage from the A/C auto amp.
to steplessly maintain the blower motor voltage in the 0 to 5 volt
range (approx.).
Front Blower Motor Co mponent Function CheckINFOID:0000000005147701
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - FRONT BLOWER
1. Push blower motor (+) switch. Blower motor should operate.
2. Push blower motor (+) switch and continue checking blower speed and fan symbol until all speeds are checked.
Is the inspection result normal?
YES >> Inspection End.
NO >> Go to diagnosis procedure. Refer to HAC-48, "
Front Blower Motor Diagnosis Procedure".
Front Blower Motor Diagnosis ProcedureINFOID:0000000005147702
Regarding Wiring Diagram information, refer to HAC-91, "Wiring Diagram".
SYMPTOM: Blower motor operation is malfunctioning.
DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR
WJIA0441E
WJIA0559E
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HAC-54
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
1.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 2.
2.CONFIRM SYMPTOM BY PERFORMING REAR BLOW ER 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-53, "
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.
NO >> • Check the rear air control (rear). Refer to HAC-56, "
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:0000000005147706
Regarding Wiring Diagram information, refer to HAC-91, "Wiring Diagram".
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
Fuse is good.
Revision: April 20092010 QX56

HAC-56
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
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 (Rear) Diagnosis Procedure #2INFOID:0000000005147707
Regarding Wiring Diagram information, refer to HAC-91, "Wiring Diagram".
REAR AIR CONTROL (REAR) INOPERATIVE
1.CHECK REAR AIR CONTROL (REAR) POWER SUPPLY
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 - Ground
: Continuity should not exist.
AWIIA0186ZZ
Battery voltage should exist.
AWIIA0182ZZ
Battery voltage should exist.
AWIIA0183ZZ
Continuity should exist.
AWIIA0184ZZ
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REAR AIR CONTROL SYSTEMHAC-59
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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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-59, "
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-56, "
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-63, "
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:0000000005147711
Regarding Wiring Diagram information, refer to HAC-91, "Wiring Diagram".
SYMPTOM:
• Temperature control (rear) operation is malfunctioning.
DIAGNOSTIC PROCEDURE FOR INOPERATIVE AIR MIX DOOR MOTOR (REAR)
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. Battery voltage should exist.
AWIIA0182ZZ
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REAR AIR CONTROL SYSTEMHAC-63
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Check voltage between A/C auto amp. harness connector M50 ter-
minal 33 and ground while rotating temperature control dial (rear)
from maximum cold to maximum heat.
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 air mix door motor (rear) harness connector and A/C auto amp. harness connector.
3. Check continuity between air mix door motor (rear) harness con- nector B155 (B) terminal 4 and A/C auto amp. harness connec-
tor M50 (A) terminal 33.
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 33 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.
Mode Door Motor (Rea r) Diagnosis ProcedureINFOID:0000000005147712
Regarding Wiring Diagram information, refer to HAC-91, "Wiring Diagram".
DIAGNOSTIC PROCEDURE INOPERATIVE MODE DOOR MOTOR (REAR)
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 Voltage
: Approx. 1V - 4.5V
AWIIA0140ZZ
Continuity should exist.
AWIIA0142ZZ
Continuity should not exist.
AWIIA0141ZZ
Battery voltage should exist.
AWIIA0182ZZ
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

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

AMBIENT SENSORHAC-75
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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AMBIENT SENSOR
Component DescriptionINFOID:0000000005147718
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor (1) is attached on the radiator core support (left
side). It detects ambient temperature and converts it into a value
which is then input into the A/C auto amp.
AMBIENT TEMPERATURE INPUT PROCESS
The A/C auto amp. includes a processing circuit for the ambient sensor input. However, when the temperature
detected by the ambient sensor increases quickly, the pr ocessing circuit retards the A/C auto amp. function. It
only allows the A/C auto amp. to recognize an ambient temperature increase of 0.33°C (0.6 °F) per 100 sec-
onds.
This prevents constant adjustments due to momentary conditions, such as stopping after high speed driving.
Although the actual ambient temperature has not changed, the temperature detected by the ambient sensor
will increase. This is because the heat from the engine comp artment can radiate to the front grille area, loca-
tion of the ambient sensor.
Ambient Sensor Diagnosis ProcedureINFOID:0000000005147719
Regarding Wiring Diagram information, refer to HAC-91, "Wiring Diagram".
DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted. (40 or 41 is
indicated on A/C auto amp. as a result of conducting the A/C auto
amp. self-diagnosis)
1.CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND
AWIIA0238ZZ
AWIIA0160GB
Revision: April 20092010 QX56