2008 INFINITI QX56 air condition

HAC-28
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MODE DOOR MOTOR
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 VOLTAGE 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 VO LTAGE CIRCUIT FOR OPEN
1. Disconnect the mode door motor harness connector.
2. Check continuity between mode door motor harness connector M142 (B) terminal 3, 1 and A/C auto amp. harness connector
M49 (C) terminal 3, M50 (A) terminal 28.
Is the inspection result normal?
YES >> Replace mode door motor. Refer to VTL-24, "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 M49 terminal 7 and ground while cycling mode switch through all
modes.
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 11.
11 .CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR SHORT TO GROUND Continuity should not exist.
AWIIA0100ZZ
Continuity should exist.
AWIIA0101ZZ
28 - 1
: Continuity should exist.
3 - 3 : Continuity should exist.
AWIIA0102ZZ
Voltage : Approx. 1V - 4.5V
AWIIA0103ZZ
Revision: March 2010 2008 QX56

MODE DOOR MOTORHAC-29
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M49 terminal 7 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
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 M142 (B) terminal 2 and A/C auto amp. harness connector M49
(A) terminal 7.
Is the inspection result normal?
YES >> Replace mode door motor. Refer to VTL-24, "Removal
and Installation".
NO >> Repair or replace harness as necessary. Continuity should not exist.
AWIIA0104ZZ
Continuity should exist.
AWIIA0105ZZ
Revision: March 2010
2008 QX56

HAC-30
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR MIX DOOR MOTOR
AIR MIX DOOR MOTOR
System DescriptionINFOID:0000000001679785
SYSTEM DESCRIPTION
SYMPTOM:• Discharge air temperature does not change.
• Air mix door motor does not operate.
SYSTEM DESCRIPTION
Component Parts
Air mix door control system components are:• A/C auto amp.
• A/C and AV switch assembly
• Air mix door motors (driver, passenger, and rear)
• PBR (built-into air mix door motors)
• In-vehicle sensor
• Ambient sensor
• Optical sensor
• Intake sensor
System Operation
The A/C auto amp. receives data from the temperature
selected by the driver side, passenger side, and rear.
The A/C auto amp. then applies a voltage to one circuit of the appropriate air mix door motor, while ground is
applied to the other circuit, causing the appropriate air mix door motor to rotate. The direction of rotation is
determined by which circuit has voltage applied to it , and which one has ground applied to it. The A/C auto
amp. monitors the air mix door positions by measur ing the voltage signal on the PBR circuits of each door.
In AUTO mode the air mix, intake, mode door, and defrost door positions are set by the A/C auto amp. which
determines the proper position based on inputs from the in-vehicle sensor, ambient sensor, optical sensor,
intake sensor, and the temperature selected by the driver and front and rear passengers.
Subsequently, HOT/COLD or DEFROST/VENT or FR ESH/RECIRCULATION operation is selected. The new
door position data is returned to the A/C auto amp.
AWIIA0106GB
Revision: March 2010 2008 QX56

AIR MIX DOOR MOTORHAC-31
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Air Mix Door Control Specification
COMPONENT DESCRIPTION
Air Mix Door Motors (front)
The driver (1) and passenger (2) air mix door motors are attached to
the front heater & cooling unit assembly. These motors rotate so that
the air mix door is opened or closed to a position set by the A/C auto
amp. Motor rotation is then conveyed through a shaft and the air mix
door position is then fed back to t
he A/C auto amp. by the PBR built
into the air mix door motors.
Air Mix Door Motor (rear)
The air mix door motor (rear) (1) is attached to the rear heater &
cooling unit assembly. These motors rotate so that the air mix door is
opened or closed to a position set by the front (or rear) air control.
Motor rotation is then conveyed through a shaft and the air mix door
position is then fed back to the A/C auto amp. by the PBR built into
the air mix door motors.
Air Mix Door Motor Component Function CheckINFOID:0000000001679786
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERAT IONAL CHECK - TEMPERATURE INCREASE
1. Turn the temperature control dial (driver) clockwise until 32 °C (90 °F) is displayed.
2. Check for hot air at discharge air outlets.
>> GO TO 2.
2.CONFIRM SYMPTOM BY PERFORMING OPERAT IONAL CHECK - TEMPERATURE DECREASE
1. Turn the temperature control dial (driver) counterclockwise until 18° C (60°F) is displayed.
2. Check for cold air at discharge air outlets.
Can a symptom be duplicated?
YES >> GO TO 4.
NO >> GO TO 3.
3.PERFORM COMPLETE OPERATIONAL CHECK
AWIIA0107GB
AWIIA0109ZZ
AWIIA0111ZZ
Revision: March 2010 2008 QX56

HAC-32
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR MIX DOOR MOTOR
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.
4.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 5.
5.CHECK AIR MIX DOOR OPERATION
Check and verify air mix door mechanism for smooth operation from 18 °C (60° F) to 32° C (90°F) in each
mode.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair as necessary.
6.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 7.
7.CHECK THE AIR MIX DOOR MOTOR PBR CIRCUIT
Perform diagnostic procedure for the air mix door motors. Refer to HAC-31, "
Air Mix Door Motor Component
Function Check".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair PBR circuit or replace air mix door motor. Refer to VTL-26, "
Removal and Installation".
8.RECHECK FOR CODES
Perform self-diagnosis. Refer to HAC-22, "
A/C and AV Switch Assembly Self-Diagnosis".
Are any self-diagnostic codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 9.
9.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".
Air Mix Door Motor (Driver) Diagnosis ProcedureINFOID:0000000001679787
SYMPTOM:• Discharge air temperature does not change.
• Air mix door motor does not operate.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (DRIVER)
1.CHECK A/C AUTO AMP. FOR POWER AND GROUND
Revision: March 2010 2008 QX56

AIR MIX DOOR MOTORHAC-33
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Turn ignition switch ON.
2. Rotate temperature control dial (driver) to 32 °C (90 °F).
3. Check voltage between A/C auto amp. harness connector M49
terminal 17 and terminal 18 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 AIR MIX DOOR MOTOR (DRIVER) 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 17, 18 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 POWER AND GROUND
1. Turn ignition switch ON.
2. Rotate temperature control dial (driver) to 32 °C (90 °F).
3. Check voltage between A/C auto amp. harness connector M49
terminal 17 and terminal 18 while rotating temperature control
dial (driver) to 18 °C (60° F).
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
4.CHECK AIR MIX DOOR MOTOR (DRIVER) 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 17 and terminal 18.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.CHECK AIR MIX DOOR MOTOR (DRIVER) CIRCUITS FOR OPEN
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 17 18 Rotate temp
control dial Battery
voltage
AWIIA0112ZZ
17 - Ground : Continuity should not exist.
18 - Ground : Continuity should not exist.
AWIIA0114ZZ
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 18 17
Rotate temp
control dial Battery
voltage
AWIIA0115ZZ
Continuity should exist.
AWIIA0116ZZ
Revision: March 2010 2008 QX56

HAC-34
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR MIX DOOR MOTOR
1. Disconnect the air mix door motor (driver) harness connector.
2. Check continuity between A/C auto amp. harness connector
M49 (A) terminal 17, 18 and the air mix door motor (driver) har-
ness connector M147 (B) terminal 1, 6.
Is the inspection result normal?
YES >> Replace air mix door motor (driver). Refer to VTL-26,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
6.CHECK A/C AUTO AMP. FOR PBR POWER AND GROUND
1. Reconnect A/C auto am p. 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 VOLTAGE 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 VO LTAGE CIRCUIT FOR OPEN
17 - 1
: Continuity should exist.
18 - 6 : Continuity should exist.
AWIIA0117ZZ
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
Revision: March 2010 2008 QX56

AIR MIX DOOR MOTORHAC-35
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Disconnect the air mix door motor (driver) harness connector.
2. Check continuity between air mix door motor (driver) harness connector M147 (B) terminal 3, 2 and A/C auto amp. harness
connector M49 (C) terminal 3 and M50 (A) terminal 28.
Is the inspection result normal?
YES >> Replace air mix door motor (driver). 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 M49 terminal 6 and ground while rotating temperature control dial
from 32 °C (90° F) to 18° C (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 M49 terminal 6 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
1. Turn ignition switch OFF.
2. Disconnect the air mix door motor (driver) harness connector and A/C auto amp. harness connector.
3. Check continuity between air mix door motor (driver) harness connector M147 (B) terminal 4 and A/C auto amp. harness con-
nector M49 (A) terminal 6.
Is the inspection result normal?
YES >> Replace air mix door motor (driver). Refer to VTL-26,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
Air Mix Door Motor (Passe nger) Diagnosis ProcedureINFOID:0000000001679788
SYMPTOM:• Discharge air temperature does not change.
• Air mix door motor does not operate.28 - 3
: Continuity should exist.
3 - 2 : Continuity should exist.
AWIIA0121ZZ
Voltage : Approx. .5V - 4.5V
AWIIA0122ZZ
Continuity should not exist.
AWIIA0123ZZ
Continuity should exist.
AWIIA0124ZZ
Revision: March 2010 2008 QX56