2006 INFINITI QX56 air condition

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)

TROUBLE DIAGNOSISATC-127
C
DE
F
G H
I
K L
M A
B
AT C
Revision: November 2009 2006 QX56
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
Gauge indicationRefrigerant cycleProbable causeCorrective action
Low-pressure side sometimes
becomes negative.

Air conditioning system
does not function and does
not cyclically cool the com-
partment air.

The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted. Refrigerant does not dis-
charge cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refriger-
ant.

Drain water from refrigerant
or replace refrigerant.

Replace liquid tank.
AC354A
Gauge indication
Refrigerant cycleProbable causeCorrective action
Low-pressure side becomes nega-
tive. Liquid tank or front/rear side of
expansion valve′s pipe is
frosted or dewed. High-pressure side is closed
and refrigerant does not flow.
↓
Expansion valve or liquid tank
is frosted.Leave the system at rest until
no frost is present. Start it
again to check whether or not
the malfunction is caused by
water or foreign particles.

If water is the cause, initially
cooling is okay. Then the
water freezes causing a
blockage. Drain water from
refrigerant or replace refrig-
erant.

If due to foreign particles,
remove expansion valve
and remove the particles
with dry and compressed air
(not shop air).

If either of the above meth-
ods cannot correct the mal-
function, replace expansion
valve.

Replace liquid tank.

Check oil for contamination.
AC362A

ATC-132
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Water Valve CircuitEJS003Y1
COMPONENT DESCRIPTION
Water Valve
The water valve (1) cuts the flow of engine coolant to the front and
rear heater cores to allow for maximum cooling during A/C opera-
tion. It is controlled by the front air control.
DIAGNOSTIC PROCEDURE FOR WATER VALVE
1. CHECK WATER VALVE POWER AND GROUND CIRCUITS
1. Disconnect water valve connector F68.
2. Turn ignition switch ON.
3. Rotate temperature control dial (driver) to 32 °C (90 °F).
4. Check voltage between water valve harness connector F68 ter- minal 1 and terminal 2 while rotating temperature control dial
(driver) to 16 °C (60 °F).
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50.
3. Check continuity between water valve harness connector F68 (A) terminal 1 and front air control harness connector M50 (B)
terminal 29.
4. Check continuity between water valve harness connector F68 (A) terminal 1 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL" .
NG >> Repair harness or connector.
WJIA1791E
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Water valve: F68 1 2Rotate temperature
control dial Battery
voltage
WJIA1792E
1 - 29 : Continuity should exist.
1 - Ground : Continuity should not exist.
WJIA1793E

TROUBLE DIAGNOSISATC-133
C
DE
F
G H
I
K L
M A
B
AT C
Revision: November 2009 2006 QX56
3. CHECK WATER VALVE POWER AND GROUND CIRCUITS
1. Rotate temperature control dial (driver) to 16 °C (60 °F).
2. Check voltage between water valve harness connector F68 ter- minal 1 and terminal 2 while rotating temperature control dial
(driver) to 32 °C (90 °F).
OK or NG
OK >> Replace the water valve.
NG >> GO TO 4.
4. CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50.
3. Check continuity between water valve harness connector F68 (A) terminal 2 and front air control harness connector M50 (B)
terminal 30.
4. Check continuity between water valve harness connector F68 (A) terminal 2 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL" .
NG >> Repair harness or connector.
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Water valve: F68 2 1Rotate temperature
control dial Battery
voltage
WJIA1794E
2 - 30 : Continuity should exist.
2 - Ground : Continuity should not exist.
WJIA1796E

ATC-134
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Ambient Sensor CircuitEJS003Y2
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor 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 front air control.
AMBIENT TEMPERATURE INPUT PROCESS
The front air control includes a processing circuit for the ambient sensor input. However, when the tempera-
ture detected by the ambient sensor increases quickly, the processing circuit retards the front air control func-
tion. It only allows the front air control to recognize an ambient temperature increase of 0.33°C (0.6 °F) per 100
seconds.
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 compartment can radiate to the front grille area, loca-
tion of the ambient sensor.
DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted. Using the
CONSULT-II, DTC B257B or B257C is displayed. Without a CON-
SULT-II, code 40 or 41 is indicated on front air control as a result of
conducting the front air control 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.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
WJIA0819E
WJIA0456E
1 - Ground : Approx. 5V
WJIA1273E

IN-CABIN MICROFILTERATC-151
C
DE
F
G H
I
K L
M A
B
AT C
Revision: November 2009 2006 QX56
IN-CABIN MICROFILTERPFP:27277
Removal and InstallationEJS003YD
FUNCTION
The air inside the passenger compartment is filtered by the in-cabin
microfilters when the heater or A/C controls are set on either the
recirculation or fresh mode. The two in-cabin microfilters are located
in the front heater and cooling unit assembly. The rear heater and
cooling unit assembly only draws in air from the passenger compart-
ment to recirculate into the passenger compartment, so the rear
heater and cooling unit assembly is not equipped with in-cabin
microfilters.
REPLACEMENT TIMING
Replacement of the two in-cabin microfilters is recommended on a regular interval depending on the driving
conditions. Refer to MA-7, "
PERIODIC MAINTENANCE" . It may also be necessary to replace the two in-cabin
microfilters as part of a component replacement if the in-cabin microfilters are damaged.
REPLACEMENT PROCEDURE
1. Remove the two lower glove box hinge pins to remove the glove
box from the instrument panel and let it hang from the cord.
2. Remove the screw and remove the in-cabin microfilter cover.
3. Remove the in-cabin microfilters from the front heater and cool- ing unit assembly housing.
4. Insert the first new in-cabin microfilter into the front heater and cooling unit assembly housing and slide it over to the right.
Insert the second new in-cabin microfilter into the front heater
and cooling unit assembly housing.
NOTE:
The in-cabin microfilters are marked with air flow arrows. The
end of the microfilter with the arrow should face the rear of the
vehicle. The arrows should point downward.
LJIA0012E
WLIA0027E
LJIA0134E
LJIA0148E

ATC-188
REFRIGERANT LINES
Revision: November 20092006 QX56
2. Pour one bottle 7.4 cc (1/4 ounce) of the HFC-134a (R-134a) fluorescent leak detection dye (J-41447) into
the HFC-134a (R-134a) dye injector (J-41459).
CAUTION:
If repairing the A/C system or replacing a component, pour the HFC-134a (R-134a) fluorescent leak
detection dye (J-41447) directly into the open system connection and proceed with the service
procedures.
3. Connect the refrigerant dye injector (J-41459) to the low-pressure service valve.
4. Start the engine and switch the A/C system ON.
5. When the A/C system is operating (compressor running), inject one bottle 7.4 cc (1/4 ounce) of HFC-134a (R-134a) fluorescent leak detection dye (J-41447) through the low-pressure service valve using HFC-
134a (R-134a) dye injector (J-41459). Refer to the manufacturer's operating instructions.
6. With the engine still running, disconnect the HFC-134a (R-134a) dye injector (J-41459) from the low-pres- sure service valve.
7. Operate the A/C system for a minimum of 20 minutes to mix the HFC-134a (R-134a) fluorescent leak detection dye (J-41447) with the A/C system oil. Depending on the leak size, operating conditions and
location of the leak, it may take from minutes to days for the HFC-134a (R-134a) fluorescent leak detec-
tion dye to penetrate an A/C system leak and become visible.
Electronic Refrigerant Leak DetectorEJS003Z8
PRECAUTIONS FOR HANDLING LEAK DETECTOR
NOTE:
When performing a refrigerant leak check, use a electronic refrigerant leak detector (J-41995) or equivalent.
Ensure that the electronic refrigerant leak detector (J-41995) is calibrated and set properly according to the
manufacturer's operating instructions.
The electronic refrigerant leak detector (J-41995) is a delicate
device. To use the electronic refrigerant leak detector (J-41995)
properly, read the manufacturer's operating instructions and perform
any specified maintenance.
1. Position the probe approximately 5 mm (3/16 in) away from thepoint to be checked as shown.
AHA281A
SHA707EA

AUDIOAV-43
C
DE
F
G H
I
J
L
M A
B
AV
Revision: November 2009 2006 QX56
4. SPIRAL CABLE CHECK
1. Disconnect spiral cable connector M102.
2. Check continuity between spiral cable terminals.
OK or NG
OK >> GO TO 5.
NG >> Replace spiral cable. Refer to SRS-48, "
SPIRAL CABLE" .
5. CHECK STEERING SWITCH RESISTANCE
Check resistance between steering switch terminals.
OK or NG
OK >> Inspection End.
NG >> Replace steering switch. Refer to AV- 5 9 , "
STEERING WHEEL AUDIO CONTROL SWITCHES" .
AV Switch CheckEKS00BIK
1. AV SWITCH SELF-DIAGNOSIS FUNCTION CHECK
1. Perform AV switch self-diagnosis function. Refer to AV- 3 1 , "
AV Switch Self-Diagnosis Function" .
Does AV switch operate normally?
YES >> Inspection End.
NO >> GO TO 2.
2. CHECK AV SWITCH POWER SUPPLY AND GROUND CIRCUIT
1. Check AV switch power supply and ground circuit. Refer to AV- 1 3 0 , "
Power Supply and Ground Circuit
Check for AV Switch" .
OK or NG
YES >> Replace AV switch. Refer to AV- 5 5 , "AV SWITCH" .
NO >> Repair malfunctioning part.
Terminals
Continuity
Spiral cable
Connector Terminal Connector Terminal
M30 32
M102 16
Ye s
31 17
24 20
WKIA4424E
Terminal Signal name ConditionResistance
(Ω )
(Approx.)
16 17 Seek (down) Depress (station) down switch. 165
Power
Depress power switch. 0
Volume (down) Depress volume down switch. 652
20 17 Seek (up) Depress (station) up switch.
165
Mode Depress mode switch. 0
Volume (up) Depress volume up switch. 652
WKIA4457E