INFINITI QX56 2007 Factory Service Manual

TROUBLE DIAGNOSISATC-91
< SERVICE INFORMATION >
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OK or NG
OK >> GO TO 17.
NG >> GO TO 16.
15.CHECK REAR BLOWER MOTOR GROUND CIRCUIT TO REAR BLOWER MOTOR RESISTOR
1. Turn ignition switch OFF.
2. Disconnect rear blower motor and rear blower motor resistor connectors.
3. Check continuity between rear blower motor connector B134 (A) terminal 1 and rear blower motor resistor harness connector
B133 (B) terminal 3.
4. Check continuity between rear blower motor connector B134 (A) terminal 1 and ground.
OK or NG
OK >> GO TO 16.
NG >> Repair harness or connector.
16.CHECK REAR BLOWER SWITCH (FRONT) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear blower motor resistor (B) connector.
3. Check continuity between rear blower switch (front) connector
M52 (A) terminals 3, 7, and 8, and rear blower motor resistor
connector B133 (B) terminals 1, 4, and 2.
OK or NG
OK >> Inspection End.
NG >> Repair harness or connector.
17.CHECK REAR BLOWER SWITCH (FRONT) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear blower switch (rear) connectors.
3. Check continuity between rear blower switch (front) connector
M52 terminals 3, 5, 7, and 8, and rear blower switch (rear) con-
nector R208 terminals 9, 6, 8, and 7.
OK or NG
OK >> GO TO 18.
NG >> Repair harness or connector. 1 - 3 : Continuity should exist.
1 - Ground : Continuity should not exist.
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Te r m i n a l N o .
Continuity
Rear blower switch (front) (A) R ear blower motor resistor (B)
31 Ye s
74
82
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Te r m i n a l N o .
Continuity
Rear blower switch (front) Rear blower switch (rear)
39
Ye s
56
78
87
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ATC-92
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
18.CHECK REAR BLOWER SWITCH (FRONT)
Refer to "Rear Blower Switch (Front)".
OK or NG
OK >> GO TO 19.
NG >> Replace rear blower switch (front). Refer to ATC-123, "
Removal and Installation"
19.CHECK REAR BLOWER SWITCH (REAR)
Refer to "Rear Blower Switch (Rear)" .
OK or NG
OK >> Inspection End.
NG >> Replace rear blower switch (rear). Refer to ATC-123, "
Removal and Installation"
20.CHECK CIRCUIT BETWEEN FRONT AIR CONTROL AND FUSE BLOCK (J/B) [REAR BLOWER MO-
TOR RELAY (COIL SIDE) POWER]
1. Disconnect front air control and fuse block (J/B) connectors
M39.
2. Check continuity between front air control harness connector M50 terminal 38 and fuse block (J/B) connector M39 terminal
3Q.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal
and Installation" .
NG >> Repair harness or connector.
COMPONENT INSPECTION
Rear Blower Motor Relay
Check circuit continuity between terminals by supplying 12 volts and
ground to coil side terminals of relays.
Rear Blower Switch (Rear)
Continuity should exist.
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TROUBLE DIAGNOSISATC-93
< SERVICE INFORMATION >
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Check continuity between terminals at each switch position.
Rear Blower Switch (Front)
Check continuity between terminals at each switch position.
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.
Rear Blower Motor Resistor
Check continuity between terminals. There will be resistance, but
there should not be an open or short between any two terminals.
Rear Air Control CircuitINFOID:0000000003533258
SYMPTOM:
• Temperature cannot be adjusted from the rear air control.
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERAT IONAL CHECK - TEMPERATURE INCREASE
1. Press AUTO switch.
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ATC-94
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
2. Turn the rear blower motor on (1-4 speed).
3. Turn the rear temperature/mode control dial clockwise.
4. Check for hot air at rear foot discharge air outlets.>> GO TO 2.
2.CONFIRM SYMPTOM BY PERFORMING OPER ATIONAL CHECK - TEMPERATURE DECREASE
1. Turn the rear temperature/mode control dial counterclockwise.
2. Check for cold air at rear vent discharge air outlets.
OK or NG?
YES >> GO TO 3.
NO >> GO TO 4.
3.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to ATC-50, "
Operational Check (Front)" .
Does another symptom exist?
YES >> Refer to ATC-32, "How to Perform Trouble Diagnosis for Quick and Accurate Repair" .
NO >> System OK.
4.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 5.
5.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to ATC-48, "
A/C System Self-Diagnosis Function" .
Are any self-diagnosis codes present?
YES >> Refer to ATC-48, "A/C System Self-Diagnosis Function".
NO >> GO TO 6.
6.CHECK REAR TEMPERATURE/MODE CONTROL DIAL OPERATION
Check and verify rear outlet position and temperat ure change when adjusted from front air control.
OK or NG?
YES >> Check rear air control circuit. Refer to "DIAGNOSTIC PROCEDURE FOR REAR AIR CONTROL".
NO >> Check air mix door motor (rear). Refer to ATC-59, "
Air Mix Door Motor Circuit" .
SYSTEM DESCRIPTION
Component Parts
Rear air control system components are:
• Front air control
• Rear air control
• Air mix door motor (rear)
• Rear blower motor relay
• Rear blower motor resistor
• Rear blower motor

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System Operation
Rear Air Control
When the rear blower switch (front) (integral to the front
air control) is in the REAR position the rear blower
motor speeds and the rear temperature and mode are contro lled by the rear blower switch (rear) and the rear
temperature switch (rear) (both integral to the rear air control).
DIAGNOSTIC PROCEDURE FOR REAR AIR CONTROL
SYMPTOM:
• Blower motor operation is malfunctioning. Refer to ATC-85, "Rear Blower Motor Circuit" .
• Temperature and mode operation is malfunctioning.
1.CHECK OPERATION FROM FRONT AIR CONTROL
Does rear temperature and mode operat e normally from front air control?
YES or NO
YES >> GO TO 2.
NO >> Refer to ATC-59, "
Air Mix Door Motor Circuit".
2.CHECK CIRCUIT BETWEEN REAR AIR CONTROL AND FRONT AIR CONTROL FOR OPEN AND
SHORT
1. Turn ignition switch OFF.
2. Disconnect front air control and rear air control connectors.
3. Check continuity between front air control harness connector
M50 terminal 33 and rear air control harness connector R209
terminal 5.
4. Check continuity between rear air control harness connector R209 terminal 5 and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3.CHECK CIRCUIT BETWEEN REAR AI R CONTROL AND AIR MIX DOOR MOTOR (REAR) FOR OPEN OR
SHORT
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33 - 5 Continuity should exist.
5 - Ground Continuity should not exist.
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ATC-96
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
1. Disconnect air mix door motor (rear) connector.
2. Check continuity between rear air control harness connector
R209 terminal 2 and 4 and air mix door motor (rear) harness
connector B155 terminal 2 and 3.
3. Check continuity between rear air control harness connector
R209 terminals 2 and 4 and ground.
OK or NG
OK >> Replace rear air control. Refer to ATC-123, "Removal and Installation"
NG >> Repair harness or connector.
Magnet Clutch CircuitINFOID:0000000003533259
SYMPTOM: Magnet clutch does not engage.
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 mode switch to select vent ( ) mode.
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.)
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to ATC-50, "
Operational Check (Front)" .
Does another symptom exist?
YES >> Refer to ATC-32, "How to Perform Trouble Diagnosis for Quick and Accurate Repair" .
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to ATC-48, "
A/C System Self-Diagnosis Function" .
Are any self-diagnosis codes present?
YES >> Refer to ATC-48, "A/C System Self-Diagnosis Function" .
NO >> GO TO 5.
5.CHECK AMBIENT SENSOR
Check and verify ambient sensor circuit. Refer to ATC-114, "
Ambient Sensor Circuit" .
>> GO TO 6.
6.CHECK INTAKE SENSOR
Check and verify intake sensor circuit. Refer to ATC-120, "
Intake Sensor Circuit" .
>> GO TO 7.
2 - 2 Continuity
should exist.
4 - 3 Continuity should exist.
2, 4 - Ground Continuity should not exist.
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TROUBLE DIAGNOSISATC-97
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7.RECHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to ATC-50, "
Operational Check (Front)" .
Does another symptom exist?
YES >> Refer to ATC-32, "How to Perform Trouble Diagnosis for Quick and Accurate Repair" .
NO >> Replace front air control. Refer to ATC-123, "
Removal and Installation" .
SYSTEM DESCRIPTION
The front air control controls compressor operation based on ambient and intake temperature and a signal
from ECM.
Low Temperature Protection Control
The front air control will turn the compressor ON or OFF as determined by a signal detected by the intake sen-
sor and the ambient sensor.
When intake air temperature is higher than the preset value, 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.
DIAGNOSTIC PROCEDURE FOR MAGNET CLUTCH
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 ATC-48, "
A/C System Self-Diagnosis Function" .
OK or NG
OK >> GO TO 2.
NG >> • Malfunctioning intake sensor. Refer to ATC-120, "
Intake Sensor Circuit" .
• Malfunctioning ambient sensor. Refer to ATC-114, "
Ambient Sensor Circuit".
2.PERFORM AUTO ACTIVE TEST
Refer to PG-20, "
Auto Active Test".
Does magnet clutch operate?
Ambient temperature °C ( °F) C o m p r e s s o r O N i n ta k e
temperature °C ( °F) Compressor OFF in-
take temperature °C ( °F)
0 (32) 2.5 (37) 2.0 (36)
10 (50) 2.5 (37) 2.0 (36)
20 (68) 2.5 (37) 1.5 (35)
30 (86) 2.0 (36) 0.5 (33)
40 (104) 2.0 (36) 0.5 (33)
50 (122) 2.0 (36) 0.5 (33)
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ATC-98
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
YES or NO
YES >> • WITH CONSULT-IIGO TO 5.
• WITHOUT CONSULT-II 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 compressor harness connector F3 terminal 1.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4.CHECK MAGNET CLUTCH CIRCUIT
Check for operation sound when applying battery voltage direct cur-
rent to terminal.
OK or NG
OK >> Replace IPDM E/R. Refer to PG-28, "Removal and
Installation of IPDM E/R".
NG >> Replace magnet clutch. Refer to ATC-155, "
Removal
and Installation for Compressor Clutch".
5.CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal. Refer to ATC-30, "
CONSULT-II
Function (HVAC)" .
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6.CHECK CIRCUIT CONTINUITY BETWEE N BCM AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect BCM connector and front air control connector.
3. Check continuity between BCM harness connector M18 terminal 27 and front air control harness connector M49 terminal 12.
OK or NG
OK >> GO TO 7.
NG >> Repair harness or connector.
11 – 1 : Continuity should exist.
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A/C SW ON : COMP ON SIG ON
A/C SW OFF : COMP ON SIG OFF
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27 - 12 Continuity should exist.
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TROUBLE DIAGNOSISATC-99
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7.CHECK VOLTAGE FOR FRONT AIR CO NTROL (COMPRESSOR ON SIGNAL)
1. Reconnect BCM connector and front air control connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 12 and ground.
OK or NG
OK >> GO TO 8.
NG-1 >> If the voltage is approx. 5V when A/C switch is ON, replace front air control. Refer to ATC-123,
"Removal and Installation".
NG-2 >> If the voltage is approx. 0V when A/C switch is OFF, replace BCM. Refer to BCS-24, "
BCM".
8.CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start engine.
2. Check voltage of refrigerant pressure sensor. Refer to EC-638
.
WITHOUT CONSULT-II
1. Start engine.
2. Check voltage between ECM harness connector F54 terminal
70 and ground.
OK or NG
OK >> • WITH CONSULT-II GO TO 9.
• WITHOUT CONSULT-II GO TO 10.
NG >> Refer to EC-638
.
9.CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to ATC-30, "
CONSULT-II Function
(HVAC)" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10.CHECK CIRCUIT CONTINUITY BETWEE N BCM AND FRONT AIR CONTROL
Te r m i n a l s
Condition Voltage
(+)
(-)
Front air con-
trol connec- tor Te r m i n a l N o .
M49 12 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
Condition Voltage
(+)
(-)
ECM con-
nector Te r m i n a l N o .
F54 70 Ground A/C switch: ON Approx. 0.36 - 3.88V
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FRONT BLOWER CONTROL
DIAL ON : FAN ON SIG ON
FRONT BLOWER CONTROL
DIAL OFF : FAN ON SIG OFF
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ATC-100
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
1. Turn ignition switch OFF.
2. Disconnect BCM connector and front air control connector.
3. Check continuity between BCM harness connector M18 terminal28 and front air control harness connector M49 terminal 10.
OK or NG
OK >> GO TO 11.
NG >> Repair harness or connector.
11 .CHECK VOLTAGE FOR FRONT AIR CONTROL (FAN ON SIGNAL)
1. Reconnect BCM connector and front air control connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 10 and ground.
OK or NG
OK >> GO TO 12.
NG-1 >> If the voltage is approx. 5V when blower moto r is ON, replace front air control. Refer to ATC-123,
"Removal and Installation" .
NG-2 >> If the voltage is approx. 0V when blower motor is OFF, replace BCM. Refer to BCS-24, "
BCM".
12.CHECK CAN COMMUNICATION
Check CAN communication. Refer to LAN-4
.
•BCM – ECM
• ECM – IPDM E/R
• ECM – Front air control
OK or NG
OK >> Inspection End.
NG >> Repair or replace malfunctioning part(s).
Insufficient CoolingINFOID:0000000003533260
SYMPTOM: Insufficient cooling
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPER ATIONAL CHECK - TEMPERATURE DECREASE
1. Press the AUTO switch.
2. Turn temperature control dial (driver) counterclockwise until 16 ° C (60 ° F) is displayed.
3. Check for cold air at discharge air outlets.
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to ATC-50, "
Operational Check (Front)" .
Does another symptom exist?
28 - 10 Continuity should exist.
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Te r m i n a l s
Condition Voltage
(+)
(-)
Front air con-
trol connector Te r m i n a l N o .
M49 10 Ground A/C switch: ON
Blower motor
operates
Approx. 0V
A/C switch: OFF Approx. 5V
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