2009 INFINITI QX56 ignition

HAC-84
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
IN-VEHICLE SENSOR
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector and in-vehicle sensor con-
nector.
3. Check continuity between in-vehicle sensor harness connector M32 (B) terminal 3 and A/C auto amp. harness connector M50
(A) terminal 31.
4. Check continuity between in-vehicle sensor harness connector M32 (B) terminal 3 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-23, "
A/C Auto Amp. Self-Diagnosis" and perform self-diagnosis.
NO >> Repair harness or connector.
In-Vehicle Sensor Component InspectionINFOID:0000000003775379
COMPONENT INSPECTION
In-vehicle Sensor
After disconnecting in-vehicle sensor connector M32, measure resis-
tance between terminals 1 and 4 at sensor component side, using
the table below.
If NG, replace in-vehicle sensor. Refer to VTL-9, "
Removal and
Installation".
3 - 31
: Continuity should exist.
2 - Ground : Continuity should exist.
3 - Ground : Continuity should not exist.
AWIIA0168ZZ
Temperature °C ( °F) Resistance kΩ
− 15 (5) 21.40
− 10 (14) 16.15
− 5 (23) 12.29
0 (32) 9.41
5 (41) 7.27
10 (50) 5.66
15 (59) 4.45
20 (68) 3.51
25 (77) 2.79
30 (86) 2.24
35 (95) 1.80
40 (104) 1.45
45 (113) 1.18
AWIIA0816ZZ
Revision: December 20092009 QX56

OPTICAL SENSORHAC-85
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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OPTICAL SENSOR
Component DescriptionINFOID:0000000003775380
COMPONENT DESCRIPTION
The optical sensor (1) is located in the center of the defroster grille. It
detects sunload entering through windshield by means of a photo
diode. The sensor converts the sunload into a current value which is
then input into the A/C auto amp.
OPTICAL INPUT PROCESS
The A/C auto amp. includes a processing circuit which averages the variations in detected sunload over a
period of time. This prevents adjustments in the ATC system operation due to small or quick variations in
detected sunload.
For example, consider driving along a road bordered by an occasional group of large trees. The sunload
detected by the optical sensor will vary whenever the tr ees obstruct the sunlight. The processing circuit aver-
ages the detected sunload over a period of time, so that the (insignificant) effect of the trees momentarily
obstructing the sunlight does not cause any change in t he ATC system operation. On the other hand, shortly
after entering a long tunnel, the system will recognize the change in sunload, and the system will react accord-
ingly.
Optical Sensor Diagnosis ProcedureINFOID:0000000003775381
DIAGNOSTIC PROCEDURE FOR OPTICAL SENSOR
SYMPTOM: Optical sensor circuit is open or shorted. Using the
CONSULT-III, DTC B257F or B2580 is displayed. Without a CON-
SULT-III, code 50 or 52 is indicated on A/C auto amp. as a result of
conducting self-diagnosis.
1.CHECK CIRCUIT CONTINUITY BETWEEN OP TICAL SENSOR AND A/C AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector and optical sensor connec- tor.
3. Check continuity between optical sensor harness connector M302 (B) terminals 1 and 2 and A/C auto amp. harness connec-
tor M50 (C) terminal 42 and M49 (A) terminal 1.
4. Check continuity between optical sensor harness connector M302 (B) terminal 1 and 2 and ground.
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AWIIA1067GB
1 - 1 : Continuity should exist.
2 - 42 : Continuity should exist.
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Revision: December 20092009 QX56

INTAKE SENSORHAC-87
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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INTAKE SENSOR
System DescriptionINFOID:0000000003775382
COMPONENT DESCRIPTION
Intake Sensor
The intake sensor is located on the heater & cooling unit assembly. It
converts temperature of air after if passes through the evaporator
into a resistance value which is then input to the A/C auto amp.
Intake Sensor Diagnosis ProcedureINFOID:0000000003775383
DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR
SYMPTOM: Intake sensor circuit is open or shorted. Using the CON-
SULT-III, DTC B2581 or B2582 is di splayed. Without a CONSULT-III,
code 56 or 57 is indicated on A/C auto amp. as a result of conducting
self-diagnosis.
1.CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND
1. Disconnect intake sensor connector.
2. Turn ignition switch ON.
3. Check voltage between intake sensor harness connector M146 terminal 2 and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 4.
2.CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND A/C AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between intake sensor harness connector M146 (B) terminal 1 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.
WJIA0571E
AWIIA0208GB
2 - Ground : Approx. 5V
WJIA1375E
1 - 26 : Continuity should exist.
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Revision: December 20092009 QX56

HAC-88
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
INTAKE SENSOR
3.CHECK INTAKE SENSOR
Check intake sensor. Refer to HAC-88, "
Intake 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-23, "
A/C Auto Amp. Self-Diagnosis" and perform self-diagnosis.
NO >> 1. Replace intake sensor. Refer to VTL-11, "
Removal and Installation".
2. Go to HAC-23, "
A/C Auto Amp. Self-Diagnosis" and perform self-diagnosis.
4.CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND A/C AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between intake sensor harness connector M146 (B) terminal 2 and A/C auto amp. harness connector M49
(A) terminal 11.
4. Check continuity between intake sensor harness connector M146 (B) terminal 2 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-23, "
A/C Auto Amp. Self-Diagnosis" and perform self-diagnosis.
NO >> Repair harness or connector.
Intake Sensor Component InspectionINFOID:0000000003775384
COMPONENT INSPECTION
Intake Sensor
After disconnecting intake sensor connector, measure resistance
between terminals 1 and 2 at sensor harness side, using the table
below.
If NG, replace intake sensor. Refer to VTL-11, "
Removal and Installa-
tion".2 - 11
: Continuity should exist.
2 - Ground : Continuity should not exist.
AWIIA0216ZZ
Temperature °C ( °F) Resistance kΩ
− 15 (5) 209.0
− 10 (14) 160.0
− 5 (23) 123.0
0 (32) 95.8
5 (41) 74.9
10 (50) 58.9
15 (59) 46.7
20 (68) 37.3
25 (77) 30.0
30 (86) 24.2
35 (95) 19.7
40 (104) 16.1
45 (113) 13.2
WJIA1378E
Revision: December 20092009 QX56

HAC-90
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
POWER SUPPLY AND GROUND
CIRCUIT FOR CONTROLLER
Check main power supply and ground circuit. Refer to HAC-90, "A/C Auto Amp Power and Ground Diagnosis
Procedure".
Is the inspection result normal?
YES >> System OK.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
A/C Auto Amp Power and Ground Diagnosis ProcedureINFOID:0000000003775387
DIAGNOSTIC PROCEDURE FOR A/C SYSTEM
SYMPTOM: A/C system does not come on.
1. CHECK POWER SUPPLY CIRCUITS FOR A/C AUTO AMP.
1. Turn ignition switch ON.
2. Check voltage between A/C auto amp. harness connector M49 (B) terminal 15 and M50 (A) terminal 27, and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Check 10A fuses [Nos. 8 and 19, located in the fuse block (J/B)]. Refer to PG-72, "
Terminal
Arrangement".
• If fuses are OK, check harness for open circuit. Repair or replace as necessary.
• If fuses are NG, replace fuse and check harness fo r short circuit. Repair or replace as neces-
sary.
2. CHECK GROUND CIRCUIT FOR A/C AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connectors.
3. Check continuity between A/C auto amp. harness connector M50 terminal 36 and ground.
Is the inspection result normal?
OK >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NG >> Repair harness or connector.
AWIIA0212GB
Terminals Ignition switch position
(+)
(-) OFF ACC ON
A/C auto
amp. con- nector Te r m i n a l N o .
M49 15 GroundApprox. 0V Approx. 0V
Battery
voltage
M50 27 Battery
voltage Battery
voltage Battery
voltage
AWIIA1073ZZ
36 - Ground : Continuity should exist.
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Revision: December 20092009 QX56

AIR CONDITIONER CONTROLHAC-91
< ECU DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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ECU DIAGNOSIS
AIR CONDITIONER CONTROL
A/C Auto Amp. Terminals Reference ValuesINFOID:0000000003775388
Measure voltage between each terminal and ground by following
Terminals and Reference Value for A/C auto amp. (1).
A/C AUTO AMP. HARNESS CO NNECTOR TERMINAL LAYOUT
TERMINALS AND REFERENCE VALUES FOR A/C AUTO AMP.
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Te r m i n a l No. Wire
color Item
Ignition
switch Condition
Voltage (V)
(Approx.)
1 G/O Optical sensor (driver) ON- 0 - 5V
2 L Air mix door motor (passe nger) ON-Battery voltage
3 P V ref ACTR (ground) ON- 5V
4 W/R Compressor ON signal ON A/C switch OFF
5V
ON A/C switch ON 0V
5 L/R Fan ON signal ON Blower switch OFF
5V
ON Blower switch ON 0V
6 SB Air mix door motor (driver) feedback ON -0 - 5V
7 GR Mode door motor feedback ON- 0 - 5V
8 R/L Illumination + ON Park lamps ONBattery voltage
9 BR Illumination - - Park lamps ON
10 LG/B Defroster door motor feedback ON -0 - 5V
11 L/B Intake sensor ON- 0 - 5V
12 G/Y Variable blower control (rear) ON- 0 - 5V
13 G/R Variable blower control (front) ON- 0 - 5V
PIIA2344E
Revision: December 20092009 QX56

HAC-92
< ECU DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR CONDITIONER CONTROL
14 G/W Air mix door motor (passenger) CW ON Clockwise rotation
Battery voltage
15 Y/G Power supply for IGN ON- Battery voltage
17 W/G Air mix door motor (driver) CW ON Clockwise rotationBattery voltage
18 G Air mix door motor (driver) CCW ON Coun terclockwise rotationBattery voltage
19 BR/W Mode door motor CW (front) ON Clockwise rotationBattery voltage
20 P/L Mode door motor CCW ON Counterclockwise rotationBattery voltage
21 G/B Intake door motor CCW ON Counterclockwise rotationBattery voltage
22 O Intake door motor CW ON Clockwise rotationBattery voltage
23 LG Defroster door motor CW ON Clockwise rotationBattery voltage
24 P/B Defroster door motor CCW ON Counterclockwise rotationBattery voltage
25 P Ambient sensor ON- 0 - 5V
26 V/R Sensor ground ON- 0V
27 Y/R Power supply for BAT -- Battery voltage
28 Y V ref ACTR (5V) ON- 0 - 5V
29 R/W Air mix door motor (passenger) feed-
back
ON
- 0 - 5V
30 R/Y Mode door motor (Rear) feedback ON -0 - 5V
31 BR/Y In-vehicle sensor motor (+) ON- Battery voltage
32 LG/R In-vehicle sensor signal ON- 0 - 5V
33 R/Y Air mix door motor (Rear) feedback ON -0 - 5V
36 B Ground -- 0V
40 P CAN-L ON- 0 - 5V
41 L CAN-H ON- 0 - 5V
42 W/V Optical sensor (passenger) ON- 0 - 5V
43 GR/R Mode door motor (Rear) CW ON Clockwise rotationBattery voltage
44 L/Y Mode door motor (Rear) CCW ON Counterclockwise rotation Battery voltage
45 Y/L Water valve ONWater valve open
Battery voltage
Water valve closed 0V
46 W/G Water valve ONWater valve open
0V
Water valve closed Battery voltage
47 O LIN BUS (rear) ON- Battery voltage
48 O LIN BUS (front) ON- Battery voltage
49 GR/R Air mix door motor (Rear) CW ONClockwise rotation Battery voltage
50 L/Y Air mix door motor (Rear) CCW ON Counterclockwise rotation Battery voltage
Te r m i n a l
No. Wire
color ItemIgnition
switch Condition Voltage (V)
(Approx.)
Revision: December 20092009 QX56

HAC-122
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MEMORY FUNCTION DOES NOT OPERATE
MEMORY FUNCTION DOES NOT OPERATE
Memory Function CheckINFOID:0000000003775398
SYMPTOM: Memory function does not operate.
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OP
ERATIONAL CHECK - MEMORY FUNCTION
1. Set the temperature to 32 °C (90 °F).
2. Rotate the front blower control dial (driver) to turn system OFF.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous temperature.
7. Rotate the front blower control dial (LH) to turn system OFF.
Can the 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.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-23, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-24, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 5.
5.CHECK POWER AND GROUND CIRCUIT
Check main power supply and ground circuit. Refer to HAC-89, "
A/C Auto Amp. Component Function Check".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace as necessary.
6.RECHECK FOR 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".
Revision: December 20092009 QX56