air condition INFINITI QX56 2008 Factory Service Manual

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
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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.
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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
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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
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MAGNET CLUTCHHAC-75
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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.
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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
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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.
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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

HAC-78
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AMBIENT SENSOR
AMBIENT SENSOR
Component DescriptionINFOID:0000000001679813
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 increas es quickly, the processing 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 co mpartment can radiate to the front grille area, loca-
tion of the ambient sensor.
Ambient Sensor Diagnosis ProcedureINFOID:0000000001679814
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 AM BIENT SENSOR AND GROUND
1. Disconnect ambient sensor connector.
2. Turn ignition switch ON.
3. Check voltage between ambient sensor harness connector E1 terminal 1 and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 4.
2.CHECK CIRCUIT CONTINUITY BETWEEN AM BIENT SENSOR AND A/C AUTO AMP.
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AWIIA0160GB
1 - Ground: Approx. 5V
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Revision: March 2010 2008 QX56

AMBIENT SENSORHAC-79
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between am bient sensor harness connector
E1 (B) terminal 2 and A/C auto amp. harness connector M49 (A)
terminal 26.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair harness or connector.
3.CHECK AMBIENT SENSOR
Check the ambient sensor circuit. Refer to HAC-79, "
Ambient Sensor Component Inspection".
Is the inspection result normal?
YES >> 1. Replace A/C auto amp. Refer to VTL-7, "Removal and Installation".
2. GO TO HAC-22, "
A/C Auto Amp. Self-Diagnosis" and perform self-diagnosis.
NO >> 1. Replace ambient sensor. 2. GO TO HAC-22, "
A/C Auto Amp. Self-Diagnosis" and perform self-diagnosis.
4.CHECK CIRCUIT CONTINUITY BETWEEN AM BIENT SENSOR AND A/C AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between am bient sensor harness connector
E1 (B) terminal 1 and A/C auto amp. harness connector M49 (A)
terminal 25.
4. Check continuity between am bient sensor harness connector
E1 (B) terminal 1 and ground.
Is the inspection result normal?
YES >> 1. Replace A/C auto amp. Refer to VTL-7, "Removal and Installation".
2. GO TO HAC-22, "
A/C Auto Amp. Self-Diagnosis" and perform self-diagnosis.
NO >> Repair harness or connector.
Ambient Sensor Component InspectionINFOID:0000000001679815
COMPONENT INSPECTION
Ambient Sensor
2 - 26 : Continuity should exist.
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1 - 25: Continuity should exist.
1 - Ground : Continuity should not exist.
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HAC-80
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AMBIENT SENSOR
After disconnecting ambient sensor (1) connector E1, measure
resistance between terminals 1 and 2 at sensor component side,
using the table below.
If NG, replace ambient sensor. Refer to
HA-45, "
Removal and Instal-
lation".
Temperature °C ( °F) Resistance kΩ
− 15 (5) 12.73
− 10 (14) 9.92
− 5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27
45 (113) 1.07
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Revision: March 2010 2008 QX56

IN-VEHICLE SENSORHAC-81
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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IN-VEHICLE SENSOR
Component DescriptionINFOID:0000000001679816
COMPONENT DESCRIPTION
In-vehicle Sensor
The in-vehicle sensor (1) is located on the lower instrument panel
LH. It converts variations in temperature of passenger compartment
air (drawn in through the integrated fan) into a resistance value. It is
then input into the A/C auto amp.
In-Vehicle Sensor Diagnosis ProcedureINFOID:0000000001679817
DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR
SYMPTOM: In-vehicle sensor circui t is open or shorted. Using the
CONSULT-III, DTC B2578 or B2579 is displayed. Without a CON-
SULT-III, code 30, 31, 44 or 46 is indicated on A/C auto amp. as a
result of conducting self-diagnosis.
1.CHECK IN-VEHICLE SENSOR CIRCUIT
Is self-diagnosis DTC B2578 or B2579 (with CONSULT-III) or code 30, 31 44 or 46 (without CONSULT-III)
present?
YES or NO?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND
AWIIA0164ZZ
AWIIA0165ZZ
AWIIA0166GB
Revision: March 2010 2008 QX56