INFINITI QX56 2008 Factory Service Manual

HAC-38
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR MIX DOOR MOTOR
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 10.
NO >> GO TO 9.
9.CHECK PBR REFERENCE VO LTAGE CIRCUIT FOR OPEN
1. Disconnect the air mix door motor (passenger) harness connec- tor.
2. Check continuity between air mix door motor (passenger) har-
ness connector M143 (B) terminal 3, 2 and A/C auto amp. har-
ness connector M49 (C) terminal 3 and M50 terminal 28.
Is the inspection result normal?
YES >> Replace air mix door motor (passenger). Refer to VTL-
26, "Removal and Installation" .
NO >> Repair or replace harness as necessary.
10.CHECK PBR FEEDBACK VOLTAGE
1. Reconnect the A/C auto amp. harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/C auto amp. harness connector M50
terminal 29 and ground while rotating temperature control dial
(passenger) from 32 °C (90° F) to 18° (60°F).
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 11.
11 .CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 terminal 29 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.
12.CHECK PBR FEEDBACK CIRCUIT FOR OPEN Continuity should exist.
AWIIA0101ZZ
28 - 3
: Continuity should exist.
3 - 2 : Continuity should exist.
AWIIA0121ZZ
Voltage : Approx. .5V - 4.5V
AWIIA0131ZZ
Continuity should not exist.
AWIIA0132ZZ
Revision: March 2010 2008 QX56

AIR MIX DOOR MOTORHAC-39
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
1. Turn ignition switch OFF.
2. Disconnect the air mix door mo tor (passenger) harness connec-
tor and A/C auto amp. harness connector.
3. Check continuity between air mix door motor (passenger) har- ness connector M143 (B) terminal 4 and A/C auto amp. harness
connector M50 (A) terminal 29.
Is the inspection result normal?
YES >> Replace air mix door motor (passenger). Refer to VTL-
26, "Removal and Installation".
NO >> Repair or replace harness as necessary. Continuity should exist.AWIIA0133ZZ
Revision: March 2010
2008 QX56

HAC-40
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
INTAKE DOOR MOTOR
INTAKE DOOR MOTOR
System DescriptionINFOID:0000000001679789
SYSTEM DESCRIPTION
SYMTOM:• Intake door motor does not operate normally.
• Intake door does not change.
SYSTEM DESCRIPTION
Component Parts
Intake door control system components are:• A/C auto amp.
• A/C and AV switch assembly
• Intake door motor (PRB built into the intake door motor)
• In-vehicle sensor
• Ambient sensor
• Optical sensor
• Intake sensor
System Operation
The intake door control determines the intake door position based on the position of the recirculation switch.
When the recirculation switch is depressed the intake
door motor rotates closing off the fresh air inlet and
recirculating the cabin air. If the recirculation switch is depressed again, the intake door motor rotates in the
opposite direction, again allowing fresh air into the cabin.
In the AUTO mode, the A/C auto amp. determines the intake door position based on the ambient temperature,
the intake air temperature and the in-vehicle temperature. When the DEF, D/F, FLOOR or OFF switches are
pushed, the A/C auto amp. sets the intake door at the fresh position.
Intake Door Control Specification
AWIIA0144GB
AWIIA0145GB
Revision: March 2010 2008 QX56

INTAKE DOOR MOTORHAC-41
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
COMPONENT DESCRIPTION
Intake door motor
The intake door motor is attached to the intake unit. It rotates so that
air is drawn from inlets set by the A/C auto amp. Motor rotation is
conveyed to a lever which activates the intake door.
Intake Door Motor Component Function CheckINFOID:0000000001679790
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - REC ( )
1. Press the mode switch to vent mode( ).
2. Press REC ( ) switch. The REC ( )indicator should illuminate.
3. Press REC ( ) switch again. The REC ( ) indicator should go out.
4. Listen for intake door position change (you should hear blower sound change slightly).
Can a symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to HAC-4, "
Operational Check
(Front)".
Can a symptom be duplicated?
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.CHECK INTAKE DOOR OPERATION
Check and verify intake door me chanism for smooth operation.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair intake door mechanism.
5.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C and AV Switch Assembly Self-Diagno-
sis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 6.
6.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".
WJIA0552E
Revision: March 2010 2008 QX56

HAC-42
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
INTAKE DOOR MOTOR
Intake Door Motor Diagnosis Procedure
INFOID:0000000001679791
SYMPTOM:
• Intake door does not change.
• Intake door motor does not operate normally.
DIAGNOSTIC PROCEDURE FOR INTAKE DOOR MOTOR
1.CHECK A/C AUTO AMP. FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Check voltage between A/C auto amp. harness connector M49 terminal 21 and terminal 22 while placing the HVAC system into
self-diagnostic mode.
Is the inspection result normal?
OK >> GO TO 3.
NO >> GO TO 2.
2.CHECK INTAKE DOOR MOTOR CIRCUITS 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 M49 terminal 21, 22 and ground.
Is the inspection result normal?
OK >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary.
3.CHECK A/C AUTO AMP. FOR GROUND AND POWER
1. Press the BACK button to back out of self-diagnostic mode.
2. Check voltage between A/C auto amp. harness connector M49 terminal 21 and terminal 22 while placing the HVAC system into
self-diagnostic mode.
Is the inspection result normal?
OK >> GO TO 4.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
4.CHECK INTAKE DOOR MOTOR AND CIRCUITS FOR OPEN
ConnectorTe r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 21
22Self-diagnostic
mode Battery volt-
age
AWIIA0146ZZ
21 - Ground : Continuity should not exist.
22 - Ground : Continuity should not exist.
AWIIA0147ZZ
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 22 21 Self-diagnostic
mode Battery
voltage
AWIIA0148ZZ
Revision: March 2010 2008 QX56

INTAKE DOOR MOTORHAC-43
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M49 terminal 21 and terminal 22.
Is the inspection result normal?
OK >> Replace intake door motor. Refer to VTL-22, "Removal
and Installation".
NO >> GO TO 5.
5.CHECK INTAKE DOOR MOTOR CIRCUITS FOR OPEN
1. Disconnect the intake door motor harness connector.
2. Check continuity between A/C auto amp. harness connector M49 (A) terminal 21, 22 and the intake door motor harness con-
nector M58 (B) terminal 1, 6.
Is the inspection result normal?
YES >> Replace intake door motor. Refer to VTL-22, "Removal
and Installation" .
NO >> Repair or replace harness as necessary. Continuity should exist.
AWIIA0149ZZ
21 - 6
: Continuity should exist.
22 - 1 : Continuity should exist.
AWIIA0234ZZ
Revision: March 2010 2008 QX56

HAC-44
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
DEFROSTER DOOR MOTOR CIRCUIT
DEFROSTER DOOR
MOTOR CIRCUIT
System DescriptionINFOID:0000000001679792
SYSTEM DESCRIPTION
Component Parts
Defroster door control system components are:• A/C auto amp.
• A/C and AV switch assembly
• Defroster door motor
• PBR (Built into defroster door motor)
• In-vehicle sensor
• Ambient sensor
• Optical sensor
• Intake sensor
System Operation
The A/C auto amp. determines defroster door position bas ed on the position of the defroster switch. When the
defroster switch is depressed, the defroster door motor rotates directing air to the defroster ducts. When any
mode other than defroster is selected, the defroster moto r rotates in the opposite direction closing off air flow
to the defroster ducts.
In the AUTO mode, the A/C auto amp. determines def roster door position based on the ambient temperature,
the intake air temperature and the in-vehicle temperature.
COMPONENT DESCRIPTION
Defroster door motor
The defroster door motor is attached to the front heater & cooling
unit assembly. The A/C auto amp. sends a voltage to rotate to the
defroster door directing the air flow either to the defroster ducts, or to
the floor ducts, depending on which way the voltage and ground are
applied to the motor leads. Motor rotation is conveyed to a lever
which activates the defroster door.
AWIIA0151GB
WJIA0592E
Revision: March 2010 2008 QX56

DEFROSTER DOOR MOTOR CIRCUITHAC-45
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
Defroster Door Motor Co mponent Function CheckINFOID:0000000001679793
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL CHECK - DEFROSTER DOOR
1. Press the mode switch and select vent ( ).
2. Press the defrost switch ( ). Defroster indicator should illuminate (on display).
3. Listen for defroster door position change (blower sound should change slightly).
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.CHECK DEFROSTER DOOR MOTOR
Perform diagnostic procedure for defroster door motor. Refer to HAC-45, "
Defroster Door Motor Component
Function Check".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair PBR circuit or replace defroster door motor. Refer to VTL-21, "
Removal and Installation".
5.CHECK DEFROSTER DOOR OPERATION
Check and verify defroster door mechanism for smooth operation.
Is the inspection result normal?
YES >> Replace defroster door motor. Refer to VTL-21, "Removal and Installation".
NO >> Repair defroster door mechanism.
Defroster Door Motor Diagnosis ProcedureINFOID:0000000001679794
SYMPTOM:
• Defroster door does not change.
• Defroster door motor does not operate normally.
DIAGNOSTIC PROCEDURE FOR DEFROSTER DOOR MOTOR
1.CHECK A/C AUTO AMP. FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Press the defroster switch ( ).
3. Check voltage between A/C auto amp. harness connector M49 terminal 24 and terminal 23 and press the defroster switch ( )
again.
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 24 23 Press de-
froster switch Battery
voltage
AWIIA0152ZZ
Revision: March 2010 2008 QX56

HAC-46
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
DEFROSTER DOOR MOTOR CIRCUIT
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK DEFROSTER DOOR MOTOR CIRCUITS 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 M49 terminal 23, 24 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.
3.CHECK A/C AUTO AMP. FOR GROUND AND POWER
1. Press the defroster switch ( ).
2. Check voltage between A/C auto amp. harness connector M49 terminal 23 and terminal 24 and pr ess the defroster switch ( )
again.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
4.CHECK DEFROSTER DOOR MOTOR AND CIRCUITS FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M49 terminal 23 and terminal 24.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.CHECK DEFROSTER DOOR MOTOR CIRCUITS FOR OPEN
1. Disconnect the defroster door motor harness connector.
2. Check continuity between A/C auto amp. harness connector M49 (A) terminal 23, 24 and the defroster door motor harness
connector M144 (B) terminal 1, 6.
Is the inspection result normal?
YES >> Replace defroster door motor. Refer to VTL-21,
"Removal and Installation".
23 - Ground : Continuity should not exist.
24 - Ground : Continuity should not exist.
AWIIA0153ZZ
Connector
Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 23 24 Press de-
froster
switch Battery
voltage
AWIIA0154ZZ
Continuity should exist.
AWIIA0155ZZ
23 - 1 : Continuity should exist.
24 - 6 : Continuity should exist.
AWIIA0156ZZ
Revision: March 2010 2008 QX56

DEFROSTER DOOR MOTOR CIRCUITHAC-47
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
NO >> Repair or replace harness as necessary.
6.CHECK A/C AUTO AMP. FOR PBR POWER AND GROUND
1. Reconnect A/C auto amp. harness connector.
2. Turn ignition switch ON.
3. 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 8.
NO >> GO TO 7.
7.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 A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary.
8.CHECK PBR REFERENCE VOLT AGE 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 10.
NO >> GO TO 9.
9.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR OPEN
1. Disconnect the defroster door motor harness connector.
2. Check continuity between defroster door motor harness connec- tor M144 (B) terminal 3, 2 and A/C auto amp. harness connector
M50 (A) terminal 28, and M49 (C) terminal 3.
Is the inspection result normal?
YES >> Replace defroster door motor. Refer to VTL-21,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
10.CHECK PBR FEEDBACK VOLTAGE
Connector Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
A/C auto amp.: M50, M49 28 35V
AWIIA0118ZZ
Continuity should not exist.
AWIIA0119ZZ
Continuity should exist.
AWIIA0120ZZ
28 - 3 : Continuity should exist.
3 - 2 : Continuity should exist.
AWIIA0121ZZ
Revision: March 2010 2008 QX56