2008 INFINITI QX56 clutch

REFRIGERATION SYSTEMHA-17
< FUNCTION DIAGNOSIS >
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FUNCTION DIAGNOSIS
REFRIGERATION SYSTEM
Refrigerant CycleINFOID:0000000001516641
REFRIGERANT FLOW
The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank,
through the front and rear evaporators, and back to the compressor. The refrigerant evaporation through the
evaporator coils are controlled by front and rear externally equalized expansion valves, located inside the front
and rear evaporator cases.
Refrigerant System ProtectionINFOID:0000000001516642
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively hi gh or low pressures by the refrigerant pressure sen-
sor, located on the condenser. If the system pressure rises above or falls below the specifications, the refriger-
ant pressure sensor detects the pressure inside the refrigerant line and sends a voltage signal to the ECM.
The ECM de-energizes the A/C relay to disengage the magnetic compressor clutch when pressure on the high
pressure side detected by refrigerant pressu re sensor is over about 2,746 kPa (28 kg/cm
2, 398 psi), or below
about 120 kPa (1.22 kg/cm
2, 17.4 psi).
PRESSURE RELIEF VALVE
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
When the pressure of refrigerant in the system incr eases to an abnormal level [more than 2,990 kPa (30.5 kg/
Revision: March 2010 2008 QX56

HA-32
< ON-VEHICLE REPAIR >
COMPRESSOR
• Replace the O-rings of the low-pressure flexible hose and high-pressure flexible hose with new
ones, apply compressor oil to the O-rings when installing them.
• After recharging the A/C system with refrigerant, check for leaks.
Removal and Installation for Compressor ClutchINFOID:0000000001516653
Magnet Clutch Assembly
REMOVAL
1. Remove the compressor. Refer to HA-31, "Removal and Installation for Compressor" .
2. Remove the center bolt while holding the clutch disc stationary using Tool as shown.
3. Remove the clutch disc and shims. CAUTION:
Retain all of the shims for installation.
4. Remove the snap ring using external snap ring pliers or suitable tool.
AWIIA1286GB
1. Magnet clutch assembly 2. Magnet coil 3. Pulley
4. Clutch disc 5. Snap ring 6. Thermal protector (built in)
7. Compressor
Tool number : — ( J-44614 )
WHA228
RHA072C
Revision: March 2010 2008 QX56

COMPRESSORHA-33
< ON-VEHICLE REPAIR >
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5. Remove the pulley using suitable tool ( A ).
CAUTION:
To prevent deformation of the pulley groove, the puller claws should be hooked under the pulley
groove and not into the pulley groove.
6. Remove the three magnet coil screws using a suitable tool and remove the magnet coil.
INSPECTION
Clutch Disc
If the contact surface shows signs of damage due to excessive heat,
replace clutch disc and pulley.
Pulley
Check the appearance of the pulley assembly. If contact surface of pulley shows signs of excessive grooving,
replace clutch disc and pulley. The contact surfaces of the pulley assembly should be cleaned with a suitable
solvent before reinstallation.
Coil
Check magnet coil for loose connections or any cracked insulation.
INSTALLATION
WJIA1017E
WHA212
WHA183
Revision: March 2010 2008 QX56

HA-34
< ON-VEHICLE REPAIR >
COMPRESSOR
1. Install the magnet coil.CAUTION:
Be sure to align the magnet coil pin with the hole in the
compressor front head.
2. Install the pulley assembly using Tool and a wrench, then install the snap ring using snap ring pliers.
3. Install the clutch disc on the compressor shaft, together with the original shim(s). Press the clutch disc down by hand.
4. Install the clutch pulley bolt using Tool, to prevent the clutch disc from turning and tighten the bolt to specification.
CAUTION:
After tightening the clutch pu lley bolt, check that the clutch
pulley rotates smoothly.
WHA213
Tool number : — (J-38873-A)
WJIA1016E
WHA184
Tool number : — ( J-44614 )
WHA229
Revision: March 2010 2008 QX56

COMPRESSORHA-35
< ON-VEHICLE REPAIR >
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5. Check the pulley clearance all the way around the clutch disc as shown.
6. If the specified clearance is not obtained, replace the adjusting spacer to readjust.
7. Install compressor. Refer to HA-31, "
Removal and Installation
for Compressor".
BREAK-IN OPERATION
When replacing compressor clutch assembly, always conduct the break-in operation. This is done by engag-
ing and disengaging the clutch about 30 times. Break-in operation raises the level of transmitted torque.
Clutch disc-to-pulley clearance : 0.3 - 0.6 mm
(0.012 - 0.024 in)
WHA194
Revision: March 2010 2008 QX56

HAC-2
MAGNET CLUTCH ............................................71
System Description .............................................. ...71
Magnet Clutch Component Function Check ........ ...71
Magnet Clutch Diagnosis Procedure ................... ...72
WATER VALVE CIRCUIT ..................................76
Description ........................................................... ...76
Water Valve Diagnosis Procedure ..........................76
AMBIENT SENSOR ...........................................78
Component Description ....................................... ...78
Ambient Sensor Diagnosis Procedure ....................78
Ambient Sensor Component Inspection .................79
IN-VEHICLE SENSOR .......................................81
Component Description ....................................... ...81
In-Vehicle Sensor Diagnosis Procedure .................81
In-Vehicle Sensor Component Inspection ..............83
OPTICAL SENSOR ...........................................84
Component Description ..........................................84
Optical Sensor Diagnosis Procedure ......................84
INTAKE SENSOR ..............................................86
System Description .............................................. ...86
Intake Sensor Diagnosis Procedure .......................86
Intake Sensor Component Inspection ................. ...87
POWER SUPPLY AND GROUND CIRCUIT
FOR CONTROLLER ..........................................
88
Component Description ....................................... ...88
A/C Auto Amp. Component Function Check ..........88
A/C Auto Amp Power and Ground Diagnosis Pro-
cedure .....................................................................
89
ECU DIAGNOSIS .......................................90
AIR CONDITIONER CONTROL ..................... ...90
A/C Auto Amp. Terminals Reference Values ..........90
Wiring Diagram .................................................... ...92
SYMPTOM DIAGNOSIS ...........................108
AIR CONDITIONER CONTROL ..................... ..108
Symptom Matrix Chart ........................................ .108
INSUFFICIENT COOLING ................................109
Component Function Check ................................ .109
Diagnostic Work Flow ...........................................110
Performance Chart ................................................113
Trouble Diagnoses for Abnormal Pressure ...........114
INSUFFICIENT HEATING ................................117
Component Function Check .................................117
NOISE ...............................................................119
Component Function Check ................................ .119
MEMORY FUNCTION DOES NOT OPERATE ..121
Memory Function Check ...................................... .121
PRECAUTION ...........................................122
PRECAUTIONS .............................................. ..122
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. .
122
Working with HFC-134a (R-134a) ........................ .122
Precaution for Service Equipment ........................123
Revision: March 2010 2008 QX56

HAC-4
< BASIC INSPECTION >[AUTOMATIC AIR CONDITIONER]
INSPECTION AND ADJUSTMENT
INSPECTION AND ADJUSTMENT
Operational Check (Front)INFOID:0000000001679764
The purpose of the operational check is to
confirm that the system operates properly.
CHECKING MEMORY FUNCTION
1. Set the temperature to 32 °C (90 °F).
2. Press the OFF switch.
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. Press the OFF switch.
If NG, go to trouble diagnosis procedure for HAC-121, "
Memory Function Check".
If OK, continue with next check.
CHECKING BLOWER
1. Press the blower speed control switch (+) once, blower should operate on low speed. The fan display should have one bar lit (on display).
2. Press the blower speed control switch (+) again, and continue checking blower speed and fan display until
all speeds are checked.
3. Leave blower on maximum speed.
If NG, go to trouble diagnosis procedure for HAC-51, "
Front Blower Motor Diagnosis Procedure".
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 HAC-15, "
Discharge
Air Flow (Front)".
Mode door position is checked in the next step.
If NG, go to trouble diagnosis procedure for HAC-26, "
Mode Door Motor (Front) Diagnosis Procedure".
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 HAC-42, "
Intake Door Motor Diagnosis Procedure".
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or vis ual 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 (drive or passenger) counterclockwise until 18° C (60°F) is displayed.
2. Check for cold air at appropriate discharge air outlets. Conditions : Engine running and at normal operating temperature
Revision: March 2010
2008 QX56

INSPECTION AND ADJUSTMENTHAC-5
< BASIC INSPECTION > [AUTOMATIC AIR CONDITIONER]
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If NG, listen for sound of air mix door motor operat ion. If OK, go to trouble diagnosis procedure for HAC-109,
"Component Function Check". If air mix door motor appears to be malfunctioning, go to HAC-31, "Air Mix Door
Motor Component Function Check".
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Rotate temperature control dial clockwise (drive or passenger) until 32 °C (90° F) is displayed.
2. Check for hot air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operat ion. If OK, go to trouble diagnosis procedure for HAC-117,
"Component Function Check". If air mix door motor appears to be malfunctioning, go to HAC-31, "Air Mix Door
Motor Component Function Check".
If OK, continue with next check.
CHECK A/C SWITCH
1. Press A/C switch when AUTO switch is ON, or in manual mode.
2. A/C switch indicator will turn ON. • Confirm that the compressor clutch engages (sound or visual inspection).
NOTE:
If current mode setting is DEF or D/F, compre ssor clutch will already be engaged and cannot be turned off.
If NG, go to trouble diagnosis procedure for HAC-72, "
Magnet Clutch Diagnosis Procedure".
If OK, continue with next check.
CHECKING AUTO MODE
1. Press AUTO switch.
2. Display should indicate AUTO.
• If ambient temperature is warm, and selected temperat ure is cool, confirm that the compressor clutch
engages (sound or visual inspection). (Discharge air and blower speed will depend on ambient, in-vehi-
cle, and set temperatures.)
If NG, go to trouble diagnosis procedure for HAC-89, "
A/C Auto Amp Power and Ground Diagnosis Proce-
dure", then if necessary, trouble diagnosis procedure for HAC-72, "Magnet Clutch Diagnosis Procedure".
If all operational checks are OK (symptom cannot be duplicated), go to malfunction Simulation Tests in HAC-
3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair" and perform tests as outlined to simu-
late driving conditions environment. If symptom appears. Refer to HAC-108, "
SymptomMatrixChart", and
perform applicable troubl e diagnosis procedures.
Operational Check (Rear)INFOID:0000000001679765
The purpose of the operational check is to confirm that the system operates properly.
CHECKING REAR BLOWER MOTOR
1. Turn the ignition switch ON.
2. Rotate rear air control (front) blower control dial to low speed.
3. Rotate the blower control dial clockwise and continue checking blower speed until all speeds are checked.
4. Leave blower on maximum speed.
5. Press the REAR CTRL switch from the rear air control (front).
6. Rotate rear air control (rear) blower control dial to low speed.
7. Rotate the blower control dial clockwise and continue checking blower speed until all speeds are checked.
8. Leave blower on maximum speed.
If NG, go to trouble diagnosis procedure for HAC-56, "
Rear Blower Motor Component Function Check".
If OK, continue with next check.
CHECKING REAR DISCHARGE AIR
Conditions : Engine running and at normal operating temperature
Revision: March 2010 2008 QX56