engine INFINITI QX56 2006 Factory Service Manual

ATC-6
PRECAUTIONS
Revision: November 20092006 QX56

If you choose to perform the repair, recover the refrigerant using only dedicated equipment and contain-
ers. Do not recover contaminated refrigerant into your existing service equipment. If your facility
does not have dedicated recovery equipment, you may contact a local refrigerant product retailer for avail-
able service. This refrigerant must be disposed of in accordance with all federal and local regulations. In
addition, replacement of all refrigerant system components on the vehicle is recommended.

If the vehicle is within the warranty period, the air conditioner warranty is void. Please contact NISSAN
Customer Affairs for further assistance.
General Refrigerant PrecautionsEJS003WR
WARNING:

Do not release refrigerant into the air. Use approved recovery/recycling equipment to capture the
refrigerant every time an air conditioning system is discharged.

Always wear eye and hand protection (goggles and gloves) when working with any refrigerant or
air conditioning system.

Do not store or heat refrigerant containers above 52 °C (125 °F).

Do not heat a refrigerant container with an open flame; if container warming is required, place the
bottom of the container in a warm pail of water.

Do not intentionally drop, puncture, or incinerate refrigerant containers.

Keep refrigerant away from open flames: poisonous gas will be produced if refrigerant burns.

Refrigerant will displace oxygen, therefore be certain to work in well ventilated areas to prevent
suffocation.

Do not pressure test or leak test HFC-134a (R-134a) service equipment and/or vehicle air condi-
tioning systems with compressed air during repair. Some mixtures of air and HFC-134a (R-134a)
have been shown to be combustible at elevated pressures. These mixtures, if ignited, may cause
injury or property damage. Additional health and safety information may be obtained from refriger-
ant manufacturers.
Precautions for Leak Detection DyeEJS003WS

The A/C system contains a fluorescent leak detection dye used for locating refrigerant leaks. An ultraviolet
(UV) lamp is required to illuminate the dye when inspecting for leaks.

Always wear fluorescence enhancing UV safety goggles to protect your eyes and enhance the visibility of
the fluorescent dye.

The fluorescent dye leak detector is not a replacement for an electronic refrigerant leak detector. The fluo-
rescent dye leak detector should be used in conjunction with an electronic refrigerant leak detector (J-
41995).

For your safety and the customer's satisfaction, read and follow all manufacturer's operating instructions
and precautions prior to performing work.

A compressor shaft seal should not be repaired because of dye seepage. The compressor shaft seal
should only be repaired after confirming the leak with an electronic refrigerant leak detector (J-41995).

Always remove any dye from the leak area after repairs are complete to avoid a misdiagnosis during a
future service.

Do not allow dye to come into contact with painted body panels or interior components. If dye is spilled,
clean immediately with the approved dye cleaner. Fluorescent dye left on a surface for an extended period
of time cannot be removed .

Do not spray the fluorescent dye cleaning agent on hot surfaces (engine exhaust manifold, etc.).

Do not use more than one refrigerant dye bottle (1/4 ounce / 7.4 cc) per A/C system.

Leak detection dyes for HFC-134a (R-134a) and CFC-12 (R-12) A/C systems are different. Do not use
HFC-134a (R-134a) leak detection dye in CFC-12 (R-12) A/C systems or CFC-12 (R-12) leak detection
dye in HFC-134a (R-134a) A/C systems or A/C system damage may result.

The fluorescent properties of the dye will remain for over three (3) years unless a compressor failure
occurs.
A/C Identification LabelEJS003WT
Vehicles with factory installed fluorescent dye have this identification label on the underside of hood.

PRECAUTIONSATC-11
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Revision: November 2009 2006 QX56
Precautions for Servicing CompressorEJS003WV

Plug all openings to prevent moisture and foreign matter from entering.

When the compressor is removed, store it in the same position as it is when mounted on the car.

When replacing or repairing compressor, follow “Maintenance of Oil Quantity in Compressor”
exactly. Refer to AT C - 2 2 , "
Maintenance of Oil Quantity in Compressor" .

Keep friction surfaces between clutch and pulley clean. If the surface is contaminated with oil,
wipe it off by using a clean waste cloth moistened with thinner.

After compressor service operation, turn the compressor shaft by hand more than 5 turns in both
directions. This will equally distribute oil inside the compressor. After the compressor is installed,
let the engine idle and operate the compressor for 1 hour.

After replacing the compressor magnet clutch, apply voltage to the new one and check for normal
operation. Refer to ATC-176, "
Removal and Installation for Compressor Clutch"
Precautions for Service EquipmentEJS003WW
RECOVERY/RECYCLING EQUIPMENT
Follow the manufacturer's instructions for machine operation and machine maintenance. Never introduce any
refrigerant other than that specified into the machine.
ELECTRONIC LEAK DETECTOR
Follow the manufacturer's instructions for tester operation and tester maintenance.
1. Plug 2. O-ringA. Torque wrench
B. Apply oil C. Do not apply oil to threadsD. NG (no good)
E. OK (okay) F. Inflated portion
WJIA1774E

ATC-22
OIL
Revision: November 20092006 QX56
OILPFP:KLG00
Maintenance of Oil Quantity in CompressorEJS003X4
The oil in the compressor circulates through the system with the refrigerant. Add oil to compressor when
replacing any component or after a large refrigerant leakage has occurred. It is important to maintain the spec-
ified amount.
If oil quantity is not maintained properly, the following malfunctions may result:

Lack of oil: May lead to a seized compressor

Excessive oil: Inadequate cooling (thermal exchange interference)
OIL
Name: NISSAN A/C System Oil Type S (DH-PS) or equivalent
Part number: KLH00-PAGS0
CHECKING AND ADJUSTING
CAUTION:
If excessive oil leakage is noted, do not perform the oil return operation.
Start the engine and set the following conditions:
Test Condition

Engine speed: Idling to 1,200 rpm

A/C switch: On

Blower fan speed: MAX position

Temp. control: Optional [Set so that intake air temperature is 25° to 30 ° C (77 ° to 86 °F)]

Intake position: Recirculation ( )

Perform oil return operation for about ten minutes
Adjust the oil quantity according to the following table.
Oil Adjusting Procedure for Components Replacement Except Compressor
After replacing any of the following major components, add the correct amount of oil to the system.
Amount of oil to be added :

*1: If refrigerant leak is small, no addition of oil is needed.
Part replaced Oil to be added to system
Remarks
Amount of oil
m (US fl oz, Imp fl oz)
Front evaporator 75 (2.5, 2.6)—
Rear evaporator 75 (2.5, 2.6)—
Condenser 75 (2.5, 2.6)—
Liquid tank 5 (0.2, 0.2)Add if compressor is not replaced.
In case of refrigerant leak 30 (1.0, 1.1)
Large leak
— Small leak *1

AIR CONDITIONER CONTROLATC-25
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AIR CONDITIONER CONTROLPFP:27500
DescriptionEJS003X5
The front air control provides automatic regulation of the vehicle's interior temperature. The system is based
on the driver's and passenger's selected "set temperature", regardless of the outside temperature changes.
This is done by utilizing a microcomputer, also referred to as the front air control, which receives input signals
from the following seven sensors:

Ambient sensor

In-vehicle sensor

Intake sensor

Optical sensor (providing one input for driver and one input for passenger side)

PBR (Position Balanced Resistor)

Vehicle speed sensor (via CAN communication)

Engine coolant temperature (via CAN communication)
The front air control uses these signals (including the set temperature) to automatically control:

Outlet air volume

Air temperature

Air distribution
The front air control also provides separate regulation of the vehicle's interior temperature for the rear passen-
ger area. The system is based on the temperature and rear blower settings selected from rear control
switches located on the front air control, or from the temperature and rear blower settings selected from rear
control switches on the rear air control, when the front air control switches are set to the rear position.
The front air control is used to select:

Outlet air volume

Air temperature/distribution
OperationEJS003X6
AIR MIX DOORS CONTROL
The air mix doors are automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by the temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.
BLOWER SPEED CONTROL
Blower speed is automatically controlled by the temperature setting, ambient temperature, in-vehicle tempera-
ture, intake temperature, amount of sunload and air mix door position.
When AUTO switch is pressed, the blower motor starts to gradually increase air flow volume (if required).
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake door is automatically controlled by the temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and by the ON-OFF operation of the compressor.
MODE DOOR CONTROL
The mode door is automatically controlled by the temperature setting, ambient temperature, in-vehicle temper-
ature, intake temperature and amount of sunload.
DEFROSTER DOOR CONTROL
The defroster door is controlled by: Turning the defroster dial to front defroster.

ATC-40
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Component Parts and Harness Connector LocationEJS003XG
ENGINE COMPARTMENT
1 Water Valve F682 Refrigerant pressure sensor E48 3 Ambient sensor E1
4 A/C Compressor F3
WJIA1912E

ATC-58
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Operational Check (Front)EJS003XL
The purpose of the operational check is to confirm that the system operates properly.
CHECKING MEMORY FUNCTION
1. Set the temperature to 90°F or 32 °C.
2. Turn front blower control dial counterclockwise until system shuts 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. Turn front blower control counterclockwise until system shuts OFF.
If NG, go to trouble diagnosis procedure for ATC-131, "
Memory Function" .
If OK, continue with next check.
CHECKING BLOWER
1. Turn front blower control clockwise, blower should operate on low speed. The blower symbol should have one blade lit (on display).
2. Turn the front blower control dial again, and continue checking blower speed and blower symbol until all speeds are checked.
3. Leave blower on MAX speed.
If NG, go to trouble diagnosis procedure for AT C - 9 5 , "
DIAGNOSTIC PROCEDURE FOR BLOWER
MOTOR"AT C - 9 5 , "DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR" .
If OK, continue with next check.
CHECKING DISCHARGE AIR
1. Press MODE switch four times and the DEF ( ) switch.
2. Each position indicator should change shape (on display).
3. Confirm that discharge air comes out according to the air distribution table. Refer to AT C - 3 0 , "
Discharge
Air Flow" .
Mode door position is checked in the next step.
If NG, go to trouble diagnosis procedure for AT C - 6 4 , "
Mode Door Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual inspection) and intake door position is at fresh
when the DEF or D/F is selected.
CHECKING RECIRCULATION (, ONLY)
1. Press recirculation ( ) switch one time. Recirculation indicator should illuminate.
2. Press recirculation ( ) switch one more time. Recirculation indicator should go off.
3. Listen for intake door position change (blower sound should change slightly).
If NG, go to trouble diagnosis procedure for AT C - 8 3 , "
Intake Door Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual inspection) and intake door position is at fresh
when the DEF or D/F is selected. REC ( ) is not allowed in DEF ( ) D/F ( ) or FOOT ( ).
CHECKING TEMPERATURE DECREASE
1. Rotate temperature control dial (driver side or passenger side) counterclockwise until 16 °C (60 °F) is dis-
played.
2. Check for cold air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation. If OK, go to trouble diagnosis procedure for ATC-121,
"Insufficient Cooling" . If air mix door motor appears to be malfunctioning, go to AT C - 7 2 , "DIAGNOSTIC PRO-
CEDURE FOR AIR MIX DOOR MOTOR (DRIVER)" or AT C - 7 6 , "DIAGNOSTIC PROCEDURE FOR AIR MIX
DOOR MOTOR (PASSENGER)" .
If OK, continue the check. Conditions : Engine running and at normal operating temperature

ATC-60
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Operational Check (Rear)EJS003XM
The purpose of the operational check is to confirm that the system operates properly.
CHECKING BLOWER
1. Turn the rear blower control dial to switch position "1". Blower should operate on low speed.
2. Turn the rear blower control dial counterclockwise to switch position "2", "3", and "4" until all speeds are
checked.
3. Leave blower on MAX speed.
If NG, go to trouble diagnosis procedure for ATC-101, "
Rear Blower Motor Circuit" .
If OK, continue the check.
CHECKING TEMPERATURE DECREASE
1. Rotate temperature and mode dial fully counterclockwise.
2. Check for cold air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation if OK, go to trouble diagnosis procedure for ATC-121,
"Insufficient Cooling" . If air mix door motor appears to be malfunctioning, go to AT C - 7 9 , "DIAGNOSTIC PRO-
CEDURE FOR AIR MIX DOOR MOTOR (REAR)" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Rotate temperature and mode dial clockwise.
2. Check for hot air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation. If OK, go to trouble diagnosis procedure for ATC-128,
"Insufficient Heating" . If air mix door motor appears to be malfunctioning, go to AT C - 7 9 , "DIAGNOSTIC PRO-
CEDURE FOR AIR MIX DOOR MOTOR (REAR)" .
If OK, continue the check. Conditions : Engine running and at normal operating temperature

ATC-94
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
SYSTEM DESCRIPTION
Component Parts
Blower speed control system components are:

Front air control

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 calculated by the front air control and variable blower control
based on input from the in-vehicle sensor, optical sensor, intake sensor and ambient sensor, and potentio tem-
perature control (PTC).
When the air flow is increased, the blower motor speed is adjusted gradually to prevent a sudden increase in
air flow.
In addition to manual air flow control and the usual automatic 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 temperature) 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).
WJIA1357E

ATC-118
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
6. CHECK CIRCUIT CONTINUITY BETWEEN BCM AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect BCM connector and front air control connector.
3. Check continuity between BCM harness connector M18 terminal 27 and front air control harness connector M49 terminal 12.
OK or NG
OK >> GO TO 7.
NG >> Repair harness or connector.
7. CHECK VOLTAGE FOR FRONT AIR CONTROL (COMPRESSOR ON SIGNAL)
1. Reconnect BCM connector and front air control connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 12 and ground.
OK or NG
OK >> GO TO 8.
NG-1 >> If the voltage is approx. 5V when A/C switch is ON, replace front air control. Refer to ATC-144,
"FRONT AIR CONTROL" .
NG-2 >> If the voltage is approx. 0V when A/C switch is OFF, replace BCM. Refer to BCS-20, "
BCM" .
8. CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start engine.
2. Check voltage of refrigerant pressure sensor. Refer to AT C - 3 4 , "
CONSULT-II Function (HVAC)" .
WITHOUT CONSULT-II
1. Start engine.
2. Check voltage between ECM harness connector F54 terminal 70 and ground.
OK or NG
OK >>
WITH CONSULT-II
GO TO 9.

WITHOUT CONSULT-II
GO TO 10.
NG >> Refer to EC-630, "
REFRIGERANT PRESSURE SENSOR" .
27 - 12 Continuity should exist.
WJIA1443E
Terminals
Condition Voltage
(+)
(-)
Front air
control con-
nector Terminal No.
M49 12 Ground A/C switch: ON Approx. 0V
A/C switch: OFF Approx. 5V
WJIA0449E
Te r m i n a l s
ConditionVoltage
(+)
(-)
ECM con-
nector Terminal No.
F54 70 Ground A/C switch: ON Approx. 0.36 - 3.88V
LJIA0124E

ATC-124
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
PERFORMANCE CHART
Test Condition
Testing must be performed as follows:
Test Reading
Recirculating-to-discharge Air Temperature Table
Ambient Air Temperature-to-operating Pressure Table
Vehicle locationIndoors 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)