ambient temp INFINITI QX56 2009 Factory User Guide

AIR MIX DOOR MOTORHAC-31
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AIR MIX DOOR MOTOR
System DescriptionINFOID:0000000003775346
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 measuring 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 retu rned to the A/C auto amp.
AWIIA0106GB
Revision: December 20092009 QX56

INTAKE DOOR MOTORHAC-41
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INTAKE DOOR MOTOR
System DescriptionINFOID:0000000003775350
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 temperatur e. 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
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DEFROSTER DOOR MOTOR CIRCUITHAC-45
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DEFROSTER DOOR MOTOR CIRCUIT
System DescriptionINFOID:0000000003775353
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: December 20092009 QX56

HAC-50
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
BLOWER MOTOR CONTROL SYSTEM
System DescriptionINFOID:0000000003775356
SYSTEM DESCRIPTION
Component Parts
Blower speed control
system components are:• A/C auto amp.
• A/C and AV switch assembly
• Variable blower control
• Front blower motor relay
• Front blower motor
• In-vehicle sensor
• Ambient sensor
• Optical sensor
• Intake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calc ulated by the A/C auto amp. and variable blower control
based on input from the in-vehicle sensor, optical sens or, intake sensor and ambient sensor, and potentio tem-
perature control (PTC).
When the air flow is increased, the blower motor s peed is adjusted gradually to prevent a sudden increase in
air flow.
In addition to manual air flow control and the usual automat ic air flow control, starting air flow control, low
water temperature starting control and high passenger compartment temperature starting control are avail-
able.
Starting Blower Speed Control
Start up from cold soak condition (Automatic mode).
In a cold start up condition where the engine coolant temperature is below 50 °C (122° F), the blower will not
operate at blower speed 1 for a short period of time (up to 210 seconds). The exact start delay time varies
depending on the ambient and engine coolant temperatures.
In the most extreme case (very low ambient temper ature) the blower starting delay will be 210 seconds as
described above. After the coolant temperature reaches 50 °C (122° F), or the 210 seconds has elapsed, the
blower speed will increase to the objective blower speed.
Start up from usual operating or hot soak condition (Automatic mode).
The blower will begin operation momentarily after the AUTO switch is pushed. The blower speed will gradually
rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
AWIIA0173GB
Revision: December 20092009 QX56

HAC-72
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MAGNET CLUTCH
MAGNET CLUTCH
System DescriptionINFOID:0000000003775369
SYSTEM DESCRIPTION
The A/C auto amp. controls compressor operation
based on ambient and intake temperature and a signal
from ECM.
Low Temperature Protection Control
The A/C auto amp. will turn the compressor ON or O FF as determined by a signal detected by the intake sen-
sor and the ambient sensor.
When intake air temperature is higher than the preset va lue, the compressor turns ON. The compressor turns
OFF when intake air temperature is lower than the pres et value. That preset value is dependent on the ambi-
ent temperature, refer to the following table.
Magnet Clutch Com ponent Function CheckINFOID:0000000003775370
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OP ERATIONAL CHECK - MAGNET CLUTCH
1. Turn ignition switch ON.
2. Press the A/C switch.
3. Press vent switch ( ).
4. Display shows , A/C. Confirm that the compress or clutch engages (sound or visual inspection). (Dis-
charge air and blower speed will depend on ambi ent, in-vehicle and set temperatures.)
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.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 AMBIENT SENSOR
Check and verify ambient sensor circuit. Refer to HAC-79, "
Ambient Sensor Diagnosis Procedure".
Ambient temperature °C ( °F) Compressor ON intake temperature °C ( °F) Compressor OFF intake temperature °C ( °F)
0 (32) 5.5 (42) 5.0 (41)
10 (50) 5.5 (42) 5.0 (41)
20 (68) 5.5 (42) 5.0 (41)
30 (86) 4.0 (39) 3.5 (38)
40 (104) 3.5 (38) 3.0 (37)
50 (122) 3.5 (38) 3.0 (37)
Revision: December 20092009 QX56

AMBIENT SENSORHAC-79
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AMBIENT SENSOR
Component DescriptionINFOID:0000000003775374
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor (1) is attached on the radiator core support (left
side). It detects ambient temperature and converts it into a value
which is then input into the A/C auto amp.
AMBIENT TEMPERATURE INPUT PROCESS
The A/C auto amp. includes a processing circuit for the ambient sensor input. However, when the temperature
detected by the ambient sensor increases quickly, the pr ocessing circuit retards the A/C auto amp. function. It
only allows the A/C auto amp. to recognize an ambient temperature increase of 0.33°C (0.6 °F) per 100 sec-
onds.
This prevents constant adjustments due to momentary conditions, such as stopping after high speed driving.
Although the actual ambient temperature has not changed, the temperature detected by the ambient sensor
will increase. This is because the heat from the engine comp artment can radiate to the front grille area, loca-
tion of the ambient sensor.
Ambient Sensor Diagnosis ProcedureINFOID:0000000003775375
DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted. (40 or 41 is
indicated on A/C auto amp. as a result of conducting the A/C auto
amp. self-diagnosis)
1.CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND
1. Disconnect ambient sensor connector.
2. Turn ignition switch ON.
3. Check voltage between ambient sensor harness connector E1 terminal 1 and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 4.
2.CHECK CIRCUIT CONTINUITY BETWEEN AM BIENT SENSOR AND A/C AUTO AMP.
AWIIA0238ZZ
AWIIA0160GB
1 - Ground: Approx. 5V
AWIIA0161ZZ
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AMBIENT SENSORHAC-81
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After disconnecting ambient sensor (1) connector E1, measure
resistance between terminals 1 and 2 at sensor component side,
using the table below.
If NG, replace ambient sensor. Refer to HA-45, "
Removal and Instal-
lation".
Temperature °C ( °F) Resistance kΩ
− 15 (5) 12.73
− 10 (14) 9.92
− 5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27
45 (113) 1.07
AWIIA0276ZZ
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POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER
HAC-89
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POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER
Component DescriptionINFOID:0000000003775385
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 bu ilt 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. Com ponent Function CheckINFOID:0000000003775386
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 ambient, 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
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AWIIA0211GB
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HAC-114
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
INSUFFICIENT COOLING
TEST READING
Recirculating-to-discharge Air Temperature Table
Ambient Air Temperature-to-operating Pressure Table
Trouble Diagnoses fo
r Abnormal PressureINFOID:0000000003775395
Whenever system′s high and/or low side pressure is unusual, diagnose using a manifold gauge. The marker
above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the stan-
Vehicle location Indoors or in the shade (in a well-ventilated place)
Doors Closed
Door window Open
Hood Open
TEMP. Max. COLD
Mode switch (Ventilation) set
Recirculation (REC) switch (Recirculation) set
Blower speed Max. speed set
Engine speed Idle speed
Operate the air conditioning system for 10 minutes before taking measurements.
Inside air (Recirculating air) at blower assembly inlet Discharge air temperature at center ventilator
°C ( °F)
Relative humidity
% Air temperature
°C ( °F)
50 - 60 20 (68)
9.9 - 13.9 (50 - 57)
25 (77) 14.6 - 18.6 (58 - 65)
30 (86) 16.8 - 21.8 (62 - 71)
35 (95) 21.1 - 27.1 (70 - 81)
40 (104) 25.3 - 31.5 (78 - 89)
60 - 70 20 (68)
11.4 - 15.2 (53 - 59)
25 (77) 15.5 - 20.0 (60 - 68)
30 (86) 19.9 - 25.0 (68 - 77)
35 (95) 24.5 - 29.6 (76 - 85)
40 (104) 28.7 - 34.9 (84 - 95)
Ambient air High-pressure (Discharge side)
kPa (kg/cm
2 , psi) Low-pressure (Suction side)
kPa (kg/cm2 , psi)
Relative humidity
% Air temperature
°C ( °F)
50 - 70 20 (68)
1020 - 1250
(10.4 - 12.7, 147.9 - 181.3) 160 - 190
(1.63 - 1.94, 23.2 - 27.6)
25 (77) 1236 - 1510
(12.6 - 15.4, 179.2 - 219) 206 - 245
(2.1 - 2.5, 29.9 - 35.6)
30 (86) 1569 - 1,922
(16.0 - 19.6, 227.6 - 278.8) 265 - 324
(2.7 - 3.3, 38.4 - 46.9)
35 (95) 1,697 - 2079
(17.3 - 21.2, 246.1 - 301.5) 304 - 363
(3.1 - 3.7, 44.1 - 52.6)
40 (104) 1971 - 2403
(20.1 - 24.5, 285.9 - 348.5) 373 - 451
(3.8 - 4.6, 54.0 - 65.4)
Revision: December 20092009 QX56

INSUFFICIENT COOLINGHAC-115
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dard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air temperature-
to-operating pressure table).
Both High- and Low-pressure Sides are Too High
High-pressure Side is Too High and Low-pressure Side is Too Low
High-pressure Side is Too Low and Low-pressure Side is Too High
Gauge indication Refrigerant cycleProbable causeCorrective action
Both high- and low-pressure sides
are too high. Pressure is reduced soon af-
ter water is splashed on con-
denser.
Excessive refrigerant charge in
refrigeration cycle
Reduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is in-
sufficient. Insufficient condenser cooling
performance
↓
1. Condenser fins are
clogged.
2. Improper fan rotation of
cooling fan • Clean condenser.
• Check and repair cooling fan
if necessary.
• Low-pressure pipe is not cold.
• When compressor is
stopped high-pressure val-
ue quickly drops by approx-
imately 196 kPa (2 kg/cm
2 ,
28 psi). It then decreases
gradually thereafter. Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure decreas-
es too slowly.)
↓
Air in refrigeration cycle
Evacuate and recharge system.
Engine tends to overheat. Engine cooling systems mal-
function. Check and repair engine cool-
ing system.
• An area of the low-pressure pipe is colder than areas
near the evaporator outlet.
• Plates are sometimes cov- ered with frost. • Excessive liquid refrigerant
on low-pressure side
• Excessive refrigerant dis-
charge flow
• Expansion valve is open a lit- tle compared with the speci-
fication.
↓
Improper expansion valve ad-
justment Replace expansion valve.
AC359A
Gauge indication
Refrigerant cycleProbable causeCorrective action
High-pressure side is too high and
low-pressure side is too low. Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot.High-pressure tube or parts lo-
cated between compressor
and condenser are clogged or
crushed.
• Check and repair or replace
malfunctioning parts.
• Check oil for contamination.
AC360A
Revision: December 20092009 QX56