INFINITI QX56 2008 Factory Service Manual

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

POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER
HAC-89
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
Check main power supply and ground circuit. Refer to HAC-89, "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:0000000001679826
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. Disconnect A/C auto amp. connectors.
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-70, "
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. 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
AWIIA0215ZZ
36 - Ground : Continuity should exist.
AWIIA0214ZZ
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]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
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

HAC-92
< ECU DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR CONDITIONER CONTROL
Wiring Diagram
INFOID:0000000001679828
AAIWA0062GB
Revision: March 2010 2008 QX56

AIR CONDITIONER CONTROLHAC-93
< ECU DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
ALIWA0021GB
Revision: March 2010 2008 QX56

HAC-94
< ECU DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR CONDITIONER CONTROL
ALIWA0050GB
Revision: March 2010
2008 QX56

AIR CONDITIONER CONTROLHAC-95
< ECU DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
AWIIA0576GB
Revision: March 2010 2008 QX56

HAC-96
< ECU DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR CONDITIONER CONTROL
AAIIA0034GB
Revision: March 2010
2008 QX56

AIR CONDITIONER CONTROLHAC-97
< ECU DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
ABIIA0572GB
Revision: March 2010 2008 QX56