2006 INFINITI QX56 clutch

PRECAUTIONSATC-11
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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

PREPARATIONATC-17
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Revision: November 2009 2006 QX56
Commercial Service ToolsEJS003X0
Tool nameDescription
(J-41810-NI)
Refrigerant identifier equipment (R-
134a) For checking refrigerant purity and
system contamination
Power tool Loosening bolts and nuts
(J-44614)
Clutch disc holding tool Clutch disc holding tool
RJIA0197E
PBIC0190E
WHA230

ATC-18
REFRIGERATION SYSTEM
Revision: November 20092006 QX56
REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleEJS003X1
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 ProtectionEJS003X2
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively high 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 pressure 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).

ATC-26
AIR CONDITIONER CONTROL
Revision: November 20092006 QX56
MAGNET CLUTCH CONTROL
When A/C switch or DEF switch is pressed, front air control inputs compressor ON signal to BCM.
BCM sends compressor ON signal to ECM, via CAN communication line.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant pressure sen-
sor signal, throttle angle sensor, etc.). If it judges compressor can be turned ON, it sends compressor ON sig-
nal to IPDM E/R, via CAN communication line.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.
SELF-DIAGNOSTIC SYSTEM
The self-diagnostic system is built into the front air control to quickly locate the cause of symptoms. Refer to
AT C - 5 6 , "
A/C System Self-diagnosis Function"
WJIA1163E

TROUBLE DIAGNOSISATC-39
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How to Perform Trouble Diagnosis for Quick and Accurate RepairEJS003XF
WORK FLOW
SYMPTOM TABLE
*1AT C - 5 8 , "Operational Check (Front)"
or ATC-60, "
Operational Check
(Rear)" .
SHA900E
Symptom Reference Page
A/C system does not come on. Go to Trouble Diagnosis Procedure for A/C System. AT C - 6 1
A/C system display is malfunctioning. Go to Navigation System. AV- 8 4
A/C system cannot be controlled.Go to Self-diagnosis Function. AT C - 5 6
Air outlet does not change.
Go to Trouble Diagnosis Procedure for Mode Door Motor. AT C - 6 4
Mode door motor is malfunctioning.
Discharge air temperature does not change.
Go to Trouble Diagnosis Procedure for Air Mix Door Motor. AT C - 7 0
Air mix door motor is malfunctioning.
Intake door does not change.
Go to Trouble Diagnosis Procedure for Intake Door Motor. AT C - 8 3
Intake door motor is malfunctioning.
Defroster door motor is malfunctioning. Go to Trouble Diagnosis Procedure for Defroster Door Motor. AT C - 8 7
Front blower motor operation is malfunction-
ing.Go to Trouble Diagnosis Procedure for Front Blower Motor.
AT C - 9 3
Rear blower motor operation is malfunction-
ing.Go to Trouble Diagnosis Procedure for Rear Blower Motor.
AT C - 1 0 1
Rear discharge air temperature and/or air
outlet does not change.Go to Trouble Diagnosis Procedure for Rear Air Control circuit.
AT C - 11 2
Magnet clutch does not engage.Go to Trouble Diagnosis Procedure for Magnet Clutch. AT C - 11 5
Insufficient coolingGo to Trouble Diagnosis Procedure for Insufficient Cooling. AT C - 1 2 1
Insufficient heatingGo to Trouble Diagnosis Procedure for Insufficient Heating. AT C - 1 2 8
NoiseGo to Trouble Diagnosis Procedure for Noise. AT C - 1 2 9
Self-diagnosis cannot be performed. Go to Trouble Diagnosis Procedure for Self-diagnosis. AT C - 1 3 0
Memory function does not operate.Go to Trouble Diagnosis Procedure for Memory Function. AT C - 1 3 1

TROUBLE DIAGNOSISATC-57
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SELF-DIAGNOSIS CODE CHART
Code No.Reference page
02 EE changed by calibration ATC-144, "
FRONT AIR CONTROL"
03 Battery voltage out of rangeSC-4, "BATTERY"
12 Air mix door motor (Passenger) circuit failureAT C - 7 6 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (PASSENGER)"
20 BCM not responding to A/C requestAT C - 11 6 , "DIAGNOSTIC PROCEDURE FOR MAGNET
CLUTCH"
21 BCM not responding to rear defroster request
GW-74, "REAR WINDOW DEFOGGER"
22 Air mix door motor (Driver) circuit failureAT C - 7 2 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (DRIVER)"
30 In-vehicle sensor circuit out of range (low)
ATC-137, "In-vehicle Sensor Circuit"31 In-vehicle sensor circuit out of range (high)
38 Air mix door motor (rear) circuit failureAT C - 7 9 , "
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (REAR)"
40 Ambient sensor circuit short
ATC-134, "Ambient Sensor Circuit"41 Ambient sensor circuit open
44 In-vehicle sensor motor circuit openATC-142, "
Intake Sensor Circuit"46 In-vehicle sensor motor circuit short
50 Optical sensor (Driver) circuit open or shortATC-140, "
Optical Sensor Circuit"52 Optical sensor (Passenger) circuit open or short
56 Intake sensor circuit shortATC-142, "
Intake Sensor Circuit"57 Intake sensor circuit open
62 Defroster door motor circuit failureAT C - 8 7 , "
Defroster Door Motor Circuit"
80 CAN bus faultLAN-26, "CAN COMMUNICATION"
82 Intake door motor (driver) circuit malfunctionAT C - 8 5 , "DIAGNOSTIC PROCEDURE FOR INTAKE DOOR
MOTOR"
90 Stuck button
ATC-144, "FRONT AIR CONTROL"
92 Mode door motor circuit failureAT C - 6 4 , "Mode Door Motor Circuit"

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

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CHECKING TEMPERATURE INCREASE
1. Rotate temperature control dial clockwise (driver side or passenger side) 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 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 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 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, compressor clutch may already be engaged.
If NG, go to trouble diagnosis procedure for AT C - 11 5
.
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 temperature 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 AT C - 6 1 , "
Power Supply and Ground Circuit for Front Air Control" ,
then if necessary, trouble diagnosis procedure for AT C - 11 5 , "
Magnet Clutch Circuit" .
If all operational checks are OK (symptom cannot be duplicated), go to malfunction Simulation Tests in AT C -
39, "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 AT C - 3 9 , "
How to Perform Trouble Diagnosis
for Quick and Accurate Repair" , AT C - 3 9 , "SYMPTOM TABLE" and perform applicable trouble diagnosis pro-
cedures.