2005 INFINITI QX4 air condition

ATC-124
TROUBLE DIAGNOSIS
Revision: October 20052005 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 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 speedMax. 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 - 6020 (68) 5.3 - 6.5 (42 - 44)
25 (77) 9.7 - 11.5 (49 - 53)
30 (86) 13.8 - 16.3 (57 - 61)
35 (95) 18.0 - 21.2 (64 - 70)
40 (104) 22.2 - 25.7 (72 - 78)
60 - 7020 (68) 6.5 - 7.7 (44 - 46)
25 (77) 11.5 - 13.3 (53 - 56)
30 (86) 16.3 - 18.8 (61 - 66)
35 (95) 21.2 - 24.0 (70 - 75)
40 (104) 25.7 - 29.2 (78 - 85)
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 - 7020 (68)680 - 840
(6.94 - 8.57, 98.6 - 121.8)160 - 198
(1.63 - 2.02, 23.2 - 28.7)
25 (77)800 - 985
(8.16 - 10.05, 116.0 - 142.8)198 - 245
(2.02 - 2.50, 28.7 - 35.5)
30 (86)940 - 1,150
(9.59 - 11.73, 136.3 - 166.8)225 - 278
(2.30 - 2.84, 32.6 - 40.3)
35 (95)1,160 - 1,410
(11.83 - 14.38, 168.2 - 204.5)273 - 335
(2.78 - 3.42, 39.6 - 48.6)
40 (104)1,325 - 1,620
(13.52 - 16.52, 192.1 - 234.9)325 - 398
(3.32 - 4.06, 47.1 - 57.7)

TROUBLE DIAGNOSIS
ATC-127
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Revision: October 20052005 QX56
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
Gauge indication Refrigerant cycle Probable cause Corrective 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 cycle Probable cause Corrective 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 lubricant for contami-
nation.
AC362A

ATC-134
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE FOR WATER VALVE
1. CHECK WATER VALVE RELAY POWER INPUT CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect water valve relay connector M7.
3. Check voltage between water valve relay harness connector ter-
minals and ground.
OK or NG
OK >> GO TO 2.
NG >> Repair harness or connector.
2. CHECK WATER VALVE CONTROL
1. Turn ignition switch ON.
2. Select MAX A/C with mode switch.
3. Check continuity between water valve relay harness connector
M7 terminal 1 (W/G) and ground, as MAX A/C is switched OFF
and ON.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50.
3. Check continuity between water valve relay harness connector
M7 terminal 1 (W/G) and front air control harness connector
M50 terminal 29 (W/G).
4. Check continuity between water valve relay harness connector
M7 terminal 1 (W/G) and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-147, "FRONT AIR CONTROL" .
NG >> Repair harness or connector.
Terminals Ignition switch position
(+)
(-) OFF ON Water valve
relay con-
nectorTe r m i n a l N o .
(Wire color)
M72 (Y/R)
GroundBattery voltage Battery voltage
3 (Y/G) 0V Battery voltage
WJIA0900E
Terminals
Condition Continuity (+)
(-) Water valve
relay con-
nectorTe r m i n a l N o .
(Wire color)
M7 1 (W/G) GroundMAX A/C: ON Yes
MAX A/C: OFF No
WJIA0901E
1 - 29 : Continuity should exist.
1 - Ground : Continuity should not exist.
WJIA0902E

TROUBLE DIAGNOSIS
ATC-137
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Revision: October 20052005 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 (P) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
WJIA0562E
WJIA0456E
1 - Ground : Approx. 5V
WJIA1971E

ATC-154
IN-CABIN MICROFILTER
Revision: October 20052005 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-190
REFRIGERANT LINES
Revision: October 20052005 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 leak detector properly, read the manufacturer's
operating instructions and perform any specified maintenance.
1. Position the probe approximately 5 mm (3/16 in) away from the
point to be checked as shown.
SHA1 96 FA
SHA707EA

AUDIO
AV-33
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AV
Revision: October 20052005 QX56
4. CHECK STEERING SWITCH RESISTANCE
Check resistance between steering switch terminals.
OK or NG
OK >> Inspection End.
NG >> Replace steering switch. Refer to AV- 4 7 , "
Removal and Installation of Steering Wheel Audio Con-
trol Switches" .
AV Switch CheckEKS00BIK
1. AV SWITCH SELF-DIAGNOSIS FUNCTION CHECK
1. Perform AV switch self-diagnosis function. Refer to AV- 2 7 , "
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-120, "
Power Supply and Ground Circuit
Check for AV Switch" .
OK or NG
YES >> Replace AV switch. Refer to AV-45, "Removal and Installation for AV Switch" .
NO >> Repair malfunctioning part.
Audio Communication Line CheckEKS00BIL
1. CHECK AUDIO COMMUNICATION LINE
Start audio communication line check. Refer to AV-126, "
Audio Communication Line Check (Between Display
Control Unit and Audio Unit)" .
OK or NG
OK >> Inspection End.
NG >> Replace malfunctioning part.
Terminal Signal name ConditionResistance
(Ω)
(Approx.)
16 17Seek (down) Depress (station) down switch. 165
Power Depress power switch. 0
Volume (down) Depress volume down switch. 652
20 17Seek (up) Depress (station) up switch. 165
Mode Depress mode switch. 0
Volume (up) Depress volume up switch. 652
WKIA3490E

AV-62
NAVIGATION SYSTEM
Revision: October 20052005 QX56

In map-matching, alternative routes to reach the destination will
be shown and prioritized, after the road on which the vehicle is
currently driven has been judged and the current-location mark
has been repositioned.
If there is an error in distance and/or direction, the alternative
routes will be shown in different order of priority, and the wrong
road can be avoided.
If two roads are running in parallel, they are of the same priority.
Therefore, the current-location mark may appear on either of
them alternately, depending on maneuvering of the steering
wheel and configuration of the road.

Map-matching does not function correctly when the road on
which the vehicle is driving is new and not recorded in the map
DVD-ROM, or when the road pattern stored in the map data and
the actual road pattern are different due to repair.
When driving on a road not present in the map, the map-match-
ing function may find another road and position the current-loca-
tion mark on it. Then, when the correct road is detected, the
current-location mark may leap to it.

Effective range for comparing the vehicle position and travel
direction calculated by the distance and direction with the road
data read from the map DVD-ROM is limited. Therefore, when
there is an excessive gap between the current vehicle position
and the position on the map, correction by map-matching is not possible.
GPS (GLOBAL POSITIONING SYSTEM)
GPS (Global Positioning System) has been developed and con-
trolled by the US Department of Defense. The system utilizes GPS
satellite (NAVSTAR), sending out radio waves while flying on an orbit
around the earth at the height of approx. 21,000 km (13,000 miles).
The GPS receiver calculates the vehicle's position in three dimen-
sions (latitude/longitude/altitude) according to the time lag of the
radio waves received from four or more GPS satellites (three-dimen-
sional positioning). If radio waves were received only from three
GPS satellites, the GPS receiver calculates the vehicle's position in
two dimensions (latitude/longitude), utilizing the altitude data calcu-
lated previously by using radio waves from four or more GPS satel-
lites (two-dimensional positioning).
Accuracy of the GPS will deteriorate under the following conditions.

In two-dimensional positioning, the GPS accuracy will deteriorate when the altitude of the vehicle position
changes.

There may be an error of approximately 10 m (30 ft) in position detected by three-dimensional positioning,
which is more accurate than two-dimensional positioning. The accuracy can be even lower depending on
the arrangement of the GPS satellites utilized for the positioning.

Position detection is not possible when the vehicle is in an area where radio waves from the GPS satellite
do not reach, such as in a tunnel, parking lot in a building, and under an elevated highway. Radio waves
from the GPS satellites may not be received when some object is located over the GPS antenna.

Position correction by GPS is not available while the vehicle is stopped.
SEL686V
SKIA0613E
SEL526V