ignition INFINITI QX56 2008 Factory Service Manual

HAC-64
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector
M50 terminal 49 and terminal 50.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> GO TO 7.
7.CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the air mix door motor (rear) harness connector.
3. Check continuity between A/C auto amp. harness connector M50 terminal 49, 50 and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair or replace harness as necessary.
8.CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR OPEN
1. Disconnect the air mix door motor (rear) harness connector.
2. Check continuity between A/C auto amp. harness connector M50 (A) terminal 49, 50 and the air mix door motor (rear) har-
ness connector B155 (B) terminal 1, 6.
Is the inspection result normal?
YES >> Replace air mix door motor (rear). Refer to VTL-26,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
9.CHECK A/C AUTO AMP. OWER AND GR OUND FOR AIR MIX DOOR MOTOR (REAR)
1. Rotate temperature control dial (front) to maximum cold.
2. Check voltage between A/C auto amp. harness connector M50 terminal 49 and terminal 50 while rotating temperature control
dial (rear) to maximum heat.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
10.CHECK A/C AUTO AMP. FOR AIR MIX DOOR MOTOR (REAR) PBR POWER AND GROUND
Continuity should exist.
AWIIA0138ZZ
49 - Ground
: Continuity should not exist.
50 - Ground : Continuity should not exist.
AWIIA0136ZZ
49 - 1 : Continuity should exist.
50 - 6 : Continuity should exist.
AWIIA0139ZZ
ConnectorTe r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M50 50 49 Rotate temp
control dial Battery
voltage
AWIIA0137ZZ
Revision: March 2010 2008 QX56

REAR AIR CONTROL SYSTEMHAC-65
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Check voltage between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 14.
NO >> GO TO 11.
11 .CHECK PBR REFERENCE VO LTAGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 12.
12.CHECK PBR REFERENCE VO LTAGE CIRCUIT FOR OPEN
1. Disconnect the air mix door motor (rear) harness connector.
2. Check continuity between air mix door motor (rear) harness con- nector B155 (B) terminal 3, 2 and A/C auto amp. harness con-
nector M50 (A) terminal 28 and M49 (C) terminal 3.
Is the inspection result normal?
YES >> Replace air mix door motor (rear). Refer to VTL-26,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
13.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
Check continuity between A/C auto amp. harness connector M50
terminal 28 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.
14.CHECK PBR FEEDBACK VOLTAGE
Connector Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
A/C auto amp.: M49, M50 28 35V
AWIIA0118ZZ
Continuity should exist.
AWIIA0120ZZ
28 - 3 : Continuity should exist.
3 - 2 : Continuity should exist.
AWIIA0121ZZ
Continuity should not exist.
AWIIA0119ZZ
Revision: March 2010 2008 QX56

HAC-66
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
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 (Rear) Diagnosis ProcedureINFOID:0000000001679807
DIAGNOSTIC PROCEDURE INOPERATIVE MODE DOOR MOTOR (REAR)
1.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 results 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: March 2010 2008 QX56

REAR AIR CONTROL SYSTEMHAC-67
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Check voltage between rear air control (front) harness connector
R108 terminal 5 and ground.
Is the inspection results normal?
YES >> GO TO 3.
NO >> GO TO 4.
3.CHECK REAR AIR CONTROL (FRONT) GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Check continuity between rear air control (front) harness con- nector R108 terminal 6 and ground.
Is the inspection results normal?
YES >> GO TO 5.
NO >> Repair harness or connector.
4.CHECK LIN BUS VOLTAGE CIRCUIT FOR OPEN
1. Disconnect the mode door motor (rear) harness connector.
2. Check continuity between rear air control (front) harness con- nector R108 (B) terminal 5 and A/C auto amp. harness connec-
tor M50 (A) terminal 48.
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.
5.CHECK A/C AUTO AMP. POWER AND GROUND FOR MODE DOOR MOTOR (REAR)
1. Reconnect all disconnected parts.
2. Turn ignition switch ON.
3. Press the mode switch to the FLOOR ( ) mode.
4. Check voltage between A/C auto amp. harness connector M50 terminal 43 and terminal 44 while pressing the mode switch to
the vent ( ) mode.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 6.
6.CHECK MODE DOOR MOTOR AND CIRCUITS FOR OPEN Battery voltage should exist.
AWIIA0183ZZ
Continuity should exist.
AWIIA0184ZZ
48 - 5
: Continuity should exist.
AWIIA0185ZZ
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M50 43 44 Press
mode
switch
(rear) Battery
voltage
AWIIA0189ZZ
Revision: March 2010 2008 QX56

HAC-68
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector
M50 terminal 43 and terminal 44.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> GO TO 7.
7.CHECK MODE DOOR MOTOR CIRCUITS FOR SHORT TO GROUND
1. Disconnect the A/C auto amp. harness connector and mode door motor (rear) harness connector
2. Check continuity between A/C auto amp. harness connector
M50 terminal 43, 44 and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair or replace harness as necessary.
8.CHECK MODE DOOR MOTOR CIRCUITS FOR OPEN
Check continuity between A/C auto amp. harness connector M50 (A)
terminal 43, 44 and the mode door motor (rear) harness connector
B156 (B) terminal 5, 6.
Is the inspection result normal?
YES >> Replace mode door motor. Refer to VTL-26, "Removal
and Installation".
NO >> Repair or replace harness as necessary.
9.CHECK A/C AUTO AMP. POWER AND GROUND FOR MODE DOOR MOTOR (REAR)
Check voltage between A/C auto amp. harness connector M50 ter-
minal 43 and terminal 44 while pressing the mode switch to the
FLOOR ( ) mode.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
10.CHECK A/C AUTO AMP. FOR MODE DOOR MOTOR (REAR) PBR POWER AND GROUND
Continuity should exist.
AWIIA0190ZZ
43 - Ground
: Continuity should not exist.
44 - Ground : Continuity should not exist.
AWIIA0192ZZ
5 - 43 : Continuity should exist.
6 - 44 : Continuity should exist.
AWIIA0191ZZ
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M50 44 43 Press
mode
switch (rear) Battery
voltage
AWIIA0196ZZ
Revision: March 2010 2008 QX56

REAR AIR CONTROL SYSTEMHAC-69
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Check voltage between A/C auto am p. harness connector M50 (A)
terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 14.
NO >> GO TO 11.
11 .CHECK PBR REFERENCE VO LTAGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 12
12.CHECK PBR REFERENCE VO LTAGE CIRCUIT FOR OPEN
1. Disconnect the mode door motor (rear) harness connector.
2. Check continuity between mode door motor (rear) harness con- nector B156 (B) terminal 3, 1 and A/C auto amp. harness con-
nector M49 (C) terminal 3, M50 (A) terminal 28.
Is the inspection result normal?
YES >> Replace mode door motor (rear). Refer to VTL-26,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
13.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 terminal 28 and ground.
Is the inspection result normal?
YES >> Replace the A/C auto amp. Refer to VTL-7, "Removal
and Installation".
NO >> Repair or replace harness as necessary.
14.CHECK PBR FEEDBACK VOLTAGE
Connector Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
A/C auto amp.: M49, M50 28 35V
AWIIA0099ZZ
Continuity should exist.
AWIIA0101ZZ
28 - 1 : Continuity should exist.
3 - 3 : Continuity should exist.
AWIIA0102ZZ
Continuity should not exist.
AWIIA0100ZZ
Revision: March 2010 2008 QX56

HAC-70
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
Check voltage between A/C auto amp. harness connector M50 ter-
minal 30 and ground while cycling mode switch through all modes.
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 mode door motor harness connector and A/C auto amp. harness connector.
3. Check continuity between mode door motor harness connector B156 (B) terminal 2 and A/C auto amp. harness connector M50
(A) terminal 30.
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 30 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. Voltage
: Approx. 1V - 4.5V
AWIIA0194ZZ
Continuity should exist.
AWIIA0195ZZ
Continuity should not exist.
AWIIA0193ZZ
Revision: March 2010 2008 QX56

MAGNET CLUTCHHAC-71
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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MAGNET CLUTCH
System DescriptionINFOID:0000000001679808
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 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.
Magnet Clutch Componen t Function CheckINFOID:0000000001679809
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL 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 ambient, 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 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 >> 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 HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 5.
5.CHECK AMBIENT SENSOR
Check and verify ambient s ensor circuit. Refer to HAC-78, "
Ambient Sensor Diagnosis Procedure".
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: March 2010 2008 QX56

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.
AWIIA0199ZZ
Revision: March 2010 2008 QX56

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
AWIIA0200ZZ
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
2008 QX56