2008 INFINITI QX56 sensor

HAC-84
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
OPTICAL SENSOR
OPTICAL SENSOR
Component DescriptionINFOID:0000000001679819
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 va ry whenever the trees 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 the 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:0000000001679820
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 OPTICAL 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.
AWIIA0169ZZ
AWIIA0205GB
1 - 1 : Continuity should exist.
2 - 42 : Continuity should exist.
AWIIA0206ZZ
Revision: March 2010 2008 QX56

OPTICAL SENSORHAC-85
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair harness or connector.
2.CHECK CIRCUIT CONTINUITY BETWEEN OPTICAL SENSOR AND BCM
1. Disconnect BCM connector.
2. Check continuity between optical sensor harness connector M302 (B) terminal 4 and BCM harness connector M18 (A) termi-
nal 18.
3. Check continuity between optical sensor harness connector M302 (B) terminal 4 and ground.
Is the inspection result normal?
YES >> Replace optical sensor. Refer to VTL-10, "Removal and Installation".
NO >> Repair harness or connector. 1, 2 - Ground. : Continuity should not exist.
4 - 18 : Continuity should exist.
4 - Ground
: Continuity should not exist.
AWIIA0207ZZ
Revision: March 2010 2008 QX56

HAC-86
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
INTAKE SENSOR
INTAKE SENSOR
System DescriptionINFOID:0000000001679821
COMPONENT DESCRIPTION
Intake Sensor
The intake sensor is located on t
he 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:0000000001679822
DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR
SYMPTOM: Intake sensor circuit is open or shorted. Using the CON-
SULT-III, DTC B2581 or B2582 is displayed. 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 IN TAKE 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.
AWIIA0209ZZ
Revision: March 2010 2008 QX56

INTAKE SENSORHAC-87
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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3.CHECK INTAKE SENSOR
Check intake sensor. Refer to HAC-87, "
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-22, "
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-22, "
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-22, "
A/C Auto Amp. Self-Diagnosis" and perform self-diagnosis.
NO >> Repair harness or connector.
Intake Sensor Component InspectionINFOID:0000000001679823
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: March 2010 2008 QX56

HAC-88
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
POWER SUPPLY AND GROUND
CIRCUIT FOR CONTROLLER
POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER
Component DescriptionINFOID:0000000001679824
COMPONENT DESCRIPTION
A/C auto amp.
The A/C auto amp. has a built-in microcomputer which processes
information sent from various sensors needed for air conditioner
operation. The air mix door motors, mode door motor, intake door
motor, defroster door motor, blower motor and compressor are then
controlled.
The A/C auto amp. is unitized with control mechanisms. When the
various switches and temperature dials are operated, data is input to
the A/C auto amp.
Self-diagnostic functions are also built into the A/C auto amp. to pro-
vide quick check of malfunctions in the auto air conditioner system.
Potentio Temperature Control (PTC)
There are two PTCs (driver and passenger) built into the A/C auto
amp. They can be set at an interval of 0.5° C (1.0°F) in the 18 °C
(60 °F) to 32° C (90°F) temperature range by rotating the temperature
dial. The set temperature is displayed.
A/C Auto Amp. Component Function CheckINFOID:0000000001679825
SYMPTOM: A/C system does not come on.
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - AUTO MODE
1. Press AUTO switch.
2. Display should indicate AUTO. Confirm that the compressor clutch engages (sound or visual inspection).
(Discharge air and blower speed will depend on am bient, in-vehicle and set temperatures.)
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 POWER AND GROUND CIRCUIT
AWIIA0573ZZ
AWIIA0211GB
Revision: March 2010 2008 QX56

HAC-90
< ECU DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR CONDITIONER CONTROL
ECU DIAGNOSIS
AIR CONDITIONER CONTROL
A/C Auto Amp. Terminals Reference ValuesINFOID:0000000001679827
Measure voltage between each terminal and ground by following
Terminals and Reference Value for A/C auto amp. (1).
A/C AUTO AMP. HARNESS CONNECTOR TERMINAL LAYOUT
TERMINALS AND REFERENCE VALUES FOR A/C AUTO AMP.
AWIIA0170ZZ
AWIIA0568ZZ
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
PIIA2344E
Revision: March 2010 2008 QX56

AIR CONDITIONER CONTROLHAC-91
< ECU DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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13 G/R Variable blower control (front) ONBlower speed (low)
1.7V
Blower speed (high) 4.5V
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 Co unterclockwise 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 ONClockwise rotation Battery voltage
44 L/Y Mode door motor (Rear) CCW ON Coun terclockwise rotationBattery 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 Co unterclockwise rotationBattery voltage
Te r m i n a l
No. Wire
color ItemIgnition
switch Condition Voltage (V)
(Approx.)
Revision: March 2010 2008 QX56

INSUFFICIENT COOLINGHAC-115
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Both High- and Low-pressure Sides are Too Low
Low-pressure Side Some
times Becomes Negative
Gauge indication Refrigerant cycleProbable causeCorrective action
High-pressure side is too low and
low-pressure side is too high. High- and low-pressure sides
become equal soon after com-
pressor operation stops.Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.
Replace compressor.
No temperature difference be-
tween high- and low-pressure
sides. Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.
Replace compressor.
AC356A
Gauge indication
Refrigerant cycleProbable causeCorrective action
Both high- and low-pressure sides
are too low. • There is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.
• Liquid tank inlet and expan- sion valve are frosted. Liquid tank inside is slightly
clogged.
• Replace liquid tank.
• Check oil for contamination.
• Temperature of expansion valve inlet is extremely low
as compared with areas
near liquid tank.
• Expansion valve inlet may be frosted.
• Temperature difference oc-
curs somewhere in high-
pressure side. High-pressure pipe located be-
tween liquid tank and expan-
sion valve is clogged.
• Check and repair malfunc-
tioning parts.
• Check oil for contamination.
Expansion valve and liquid
tank are warm or only cool
when touched. Low refrigerant charge.
↓
Leaking fittings or compo-
nents.Check refrigerant system for
leaks. Refer to HA-24, "
Check-
ing of Refrigerant Leaks".
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted. Expansion valve closes a little
compared with the specifica-
tion.
↓
1. Improper expansion
valve adjustment.
2. Malfunctioning expansion valve.
3. Outlet and inlet may be clogged. • Remove foreign particles by
using compressed air.
• Check oil for contamination.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet. Low-pressure pipe is clogged
or crushed.• Check and repair malfunc-
tioning parts.
• Check oil for contamination.
Air flow volume is too low. Evaporator is frozen. • Check intake sensor circuit.
Refer to HAC-86, "
Intake
Sensor Diagnosis Proce-
dure".
• Repair evaporator fins.
• Replace evaporator.
• Refer to HAC-50, "
Front
Blower Motor Component
Function Check".
AC353A
Revision: March 2010 2008 QX56