2007 INFINITI QX56 light

TROUBLE DIAGNOSISATC-107
< SERVICE INFORMATION >
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Low-pressure Side Some
times Becomes Negative
Low-pressure Side Becomes Negative
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too low. • There is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.
• Liquid tank inlet and expan-
sion valve are frosted. Liquid tank inside is slightly
clogged.
• Replace liquid tank.
• Check oil for contamination.
• Temperature of expansion valve inlet is extremely low
as compared with areas
near liquid tank.
• Expansion valve inlet may be frosted.
• Temperature difference oc- curs somewhere in high-
pressure side. High-pressure pipe located be-
tween liquit tank and expan-
sion valve is clogged.
• Check and repair malfunc-
tioning parts.
• Check oil for contamination.
Expansion valve and liquid
tank are warm or only cool
when touched. Low refrigerant charge.
↓
Leaking fittings or compo-
nents.Check refrigerant system for
leaks. Refer to
ATC-166,
"Checking of Refrigerant
Leaks" .
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted. Expansion valve closes a little
compared with the specifica-
tion.
↓
1. Improper expansion
valve adjustment.
2. Malfunctioning expansion
valve.
3. Outlet and inlet may be clogged. • Remove foreign particles by
using compressed air.
• Check oil for contamination.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet. Low-pressure pipe is clogged
or crushed.• Check and repair malfunc-
tioning parts.
• Check oil for contamination.
Air flow volume is too low. Evaporator is frozen. • Check intake sensor circuit.
Refer to ATC-120, "
Intake
Sensor Circuit" .
• Repair evaporator fins.
• Replace evaporator.
• Refer to AT C - 7 8 , "
Front
Blower Motor Circuit" .
AC353A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes be-
comes negative. • Air conditioning system does
not function and does not cy-
clically cool the compart-
ment air.
• The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted. Refrigerant does not discharge
cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refrigerant.
• Drain water from refrigerant
or replace refrigerant.
• Replace liquid tank.
AC354A

TROUBLE DIAGNOSISATC-119
< SERVICE INFORMATION >
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COMPONENT INSPECTION
In-vehicle Sensor
After disconnecting in-vehicle sensor connector M32, measure resis-
tance between terminals 1 and 4 at sensor component side, using
the table below.
If NG, replace in-vehicle sensor.
Optical Sensor CircuitINFOID:0000000003533268
COMPONENT DESCRIPTION
The optical sensor is located in t he center of the defroster grille. It
detects sunload entering through windshield by means of a photo
diode. The sensor converts the sunload into a current value which is
then input into the front air control.
OPTICAL INPUT PROCESS
The front air control includes a processing circuit whic h averages the variations in detected sunload over a
period of time. This prevents adjustments in the ATC system operation due to small or quick variations in
detected sunload.
For example, consider driving along a road bordered by an occasional group of large trees. The sunload
detected by the optical sensor will vary whenever the tr ees obstruct the sunlight. The processing circuit aver-
ages the detected sunload over a period of time, so that the (insignificant) effect of the trees momentarily
obstructing the sunlight does not cause any change in t he ATC system operation. On the other hand, shortly
after entering a long tunnel, the system will recognize t he change in sunload, and the system will react accord-
ingly.
DIAGNOSTIC PROCEDURE FOR OPTICAL SENSOR
Temperature °C ( °F) Resistance k Ω
− 15 (5) 21.40
− 10 (14) 16.15
− 5 (23) 12.29
0 (32) 9.41
5 (41) 7.27
10 (50) 5.66
15 (59) 4.45
20 (68) 3.51
25 (77) 2.79
30 (86) 2.24
35 (95) 1.80
40 (104) 1.45 45 (113) 1.18
WJIA0825E
WJIA0569E

ATC-166
< SERVICE INFORMATION >
REFRIGERANT LINES
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-rings on the A/C refrigerant pipes with new ones, then apply compressor oil to them
when installing them.
• After charging refrigerant, check for leaks.
Checking of Refrigerant LeaksINFOID:0000000003533307
PRELIMINARY CHECK
Perform a visual inspection of all refrigeration parts, fittings, hoses and components for signs of A/C oil leak-
age, damage, and corrosion. Any A/C oil leakage may indi cate an area of refrigerant leakage. Allow extra
inspection time in these areas when using either an el ectronic refrigerant leak detector (J-41995) or fluores-
cent dye leak detector (J-42220).
If any dye is observed using a fluorescent dye leak detector (J-42220), confirm the leak using a electronic
refrigerant leak detector (J-41995). It is possible that the dye is from a prior leak that was repaired and not
properly cleaned.
When searching for leaks, do not stop when one leak is found but continue to check for additional leaks at all
system components and connections.
When searching for refrigerant leaks using an electronic refrigerant leak detector (J-41995), move the probe
along the suspected leak area at 25 - 50 mm (1 - 2 in) per second and no further than 6 mm (1/4 in) from the
component.
CAUTION:
Moving the electronic refrigerant l eak detector probe slower and clo ser to the suspected leak area will
improve the chances of finding a leak.
Checking System for L eaks Using the Fluoresc ent Dye Leak DetectorINFOID:0000000003533308
1. Check the A/C system for leaks using the fluorescent dye leak detector and safety goggles (J-42220) in a
low sunlight area (area without windows preferable). Il luminate all components, fittings and lines. The dye
will appear as a bright green/yellow area at the point of leakage. Fluorescent dye observed at the evapo-
rator drain opening indicates an evaporator core asse mbly leak (tubes, core or expansion valve).
2. If the suspected area is difficult to see, use an adjustable mirror or wipe the area with a clean shop rag or
cloth, then inspect the shop rag or cloth with the fl uorescent dye leak detector (J-42220) for dye residue.
3. After the leak is repaired, remove any residual dye using refrigerant dye cleaner (J-43872) to prevent
future misdiagnosis.
4. Perform a system performance check and then verify t he leak repair using a electronic refrigerant leak
detector (J-41995).
NOTE:
• Other gases in the work area or substances on the A/C components, for example, anti-freeze, wind-
shield washer fluid, solvents and oils, may falsely tri gger the leak detector. Make sure the surfaces to be
checked are clean.
• Clean with a dry cloth or blow off with shop air.
• Do not allow the sensor tip of the electronic refri gerant leak detector (J-41995) to contact with any sub-
stance. This can also cause false readings and may damage the detector.
Dye InjectionINFOID:0000000003533309
NOTE:
This procedure is only necessary when recharging the system or when the compressor has seized and must
be replaced.
1. Check the A/C system static (at rest) pressure . Pressure must be at least 345 kPa (3.52 kg/cm
2 , 50 psi).
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: Expansion valve bolts : 4 N·m (0.41 kg-m, 35 in-lb)
A/C refrigerant pipe to exp
ansion valve bolt : Refer to ATC-152, "
Component".

AV-20
< SERVICE INFORMATION >
AUDIO
Terminal and Reference Value for Audio Unit
INFOID:0000000003533667
Te r m i n a l
(Wire color)
ItemSignal
input/
outputCondition
Reference value
(Approx.)Example of symptom
+–Ignition
switchOperation
2 (W) 1 (B)Audio sound
signal front
LHOutput ONReceive audio
signalNo sound from front
door speaker LH or
tweeter LH.
4 (Y) 3 (BR)Audio sound
signal front
RHOutput ONReceive audio
signalNo sound from front
door speaker RH or
tweeter RH.
5 (G/W) GroundAntenna
signalOutput ON – More than 10V Poor radio reception.
6 (Y) GroundBattery pow-
erInput – – Battery voltageSystem does not
work properly.
7 (BR) GroundIllumination
control sig-
nalInput ONIllumination con-
trol switch is op-
erated by lighting
switch in 1st posi-
tion.Changes between 0 and 12VAudio unit illumina-
tion cannot be con-
trolled.
8 (R/L) GroundIllumination
signalInput OFFLighting switch is
in 1st position.Battery voltageAudio unit illumina-
tion does not come
on when lighting
switch is in 1st posi-
tion. Lighting switch is
OFF.3V or less
9–Shield –– – 0VInterference and dis-
tortion heard from
speakers.
10 (V) Ground ACC signal Input ON – Battery voltageSystem does not
work properly.
12 (G/W) GroundAmp. ON
signalOutput ON – More than 6.5VAmp. does not work
properly.
14 (BR) 13 (B/R)Audio sound
signal rear
LHOutput ONReceive audio
signalNo sound from rear
door speaker LH or
rear door tweeter LH.
SKIA0177E
SKIA0177E
SKIA0177E

AUDIO
AV-25
< SERVICE INFORMATION >
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Terminal and Reference Value for Rear Audio Remote Control UnitINFOID:0000000003533669
28 (Y) 27 (BR)Audio sound
signal front RHInput ONReceive audio
signalNo sound from
front door speaker
RH or front tweeter
RH.
30 (W) 29 (B)Audio sound
signal front LHInput ONReceive audio
signalNo sound from
front door speaker
LH or front tweeter
LH.
31 (G/W) GroundAmp. ON sig-
nalInput ON – More than 6.5VSystem does not
work properly. Te r m i n a l
(wire color)
ItemSignal
input/
outputCondition
Reference value
(Approx.)Example of
symptom
+–Ignition
switchOperation
SKIA0177E
SKIA0177E
Te r m i n a l
(Wire color)
ItemSignal
input/
outputCondition
Reference value
(Approx.)Example of symptom
+–Ignition
switchOperation
2 (G) 1 (B)Audio sound
signal LHInput ONReceive audio
signalNo sound from LH
headphone channel.
4 (W) 3 (R)Audio sound
signal RHInput ONReceive audio
signalNo sound from RH
headphone channel.
5 – Shield – – – 0VInterference and dis-
tortion heard from
headphones or rear
audio remote control
unit switches not op-
erating properly.
6 (R/L) Ground Illumination Input ONLighting switch
ON12V
Rear audio remote
control unit does not
illuminate. Lighting switch
OFF0V
7 (LG) –Remote
control
ground–– – 0VRear audio remote
control unit switches
do not function.
SKIA0177E
SKIA0177E

AV-26
< SERVICE INFORMATION >
AUDIO
Terminal and Reference Value for AV Switch
INFOID:0000000003533670
8 (O) GroundRemote
control en-
able signalInput ON Audio unit ON 5VRear audio remote
control unit does not
operate.
9 (V) GroundRemote
control AInput ON Audio unit ON 5VRear audio remote
control unit does not
operate properly.
10 (P) GroundRemote
control BInput ON Audio unit ON 5VRear audio remote
control unit does not
operate properly.
11
(BR/Y)GroundRemote
control CInput ON Audio unit ON 5VRear audio remote
control unit does not
operate properly.
12 (L) GroundRemote
control DInput ON Audio unit ON 5VRear audio remote
control unit does not
operate properly.
13 (V) GroundRemote
control
switch pow-
er supplyInput ON Audio unit ON 12VRear audio remote
control does not op-
erate.
15 (B) – Ground – ON – 0V –Te r m i n a l
(Wire color)
ItemSignal
input/
outputCondition
Reference value
(Approx.)Example of symptom
+–Ignition
switchOperation
Te r m i n a l N o .
(Wire color)
ItemSignal
input/
outputCondition
Vo l ta g e
(Approx.)Example of
symptom
+–Ignition
switchOperation
1 (Y) Ground Battery power Input OFF – Battery voltageSystem does not
work properly.
2 (V) Ground ACC signal Input ACC – Battery voltageSystem does not
work properly.
3 (R/L) GroundIllumination
signalInput OFFLighting switch is
ON (position 1).Battery voltageAV switch illumi-
nation does not
come on when
lighting switch is
ON (position 1). Turn lighting switch
OFF.Approx. 3.0V or less
4 (BR) GroundIllumination
control signalInput ONIllumination control
switch is operated
by lighting switch in
1st position.Changes between 0 and 12V.AV switch illumi-
nation cannot be
controlled.
5 (B) Ground Ground – ON – 0V –
6 (V) GroundCommunica-
tion signal (+)Input/
outputON –System does not
work properly.
7 – Shield ground – – – –
SKIA0175E

AUDIO
AV-31
< SERVICE INFORMATION >
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• Loss of power to the satellite radio tuner (factory installed)
• Open or short in the REQ1, TXD, or RXD circuits.
If the satellite antenna is disconnected or inoperative, the display unit will display ANTENNA.
Noise InspectionINFOID:0000000003533674
The vehicle itself can be a source of noise if noise prevention parts or electrical equipment is malfunctioning.
Check if noise is caused and/or changed by engine speed, ignition switch turned to each position, and opera-
tion of each piece of electrical equipment, and determine the cause.
NOTE:
The source of the noise can be found easily by listening to the noise while removing the fuses of electrical
components, one by one.
TYPE OF NOISE AND POSSIBLE CAUSE
Power Supply Circuit InspectionINFOID:0000000003533675
1.CHECK FUSES
Check that the following fuses are not blown.
OK or NG
OK >> GO TO 2.
NG >> If fuse is blown, be sure to eliminate cause of blown fuse before installing new fuse. Refer to PG-
3.
2.POWER SUPPLY CIRCUIT CHECK
1. Disconnect audio unit connector M43, subwoofer connector B72 and BOSE speaker amp. connector
M112.
2. Check voltage between the audio unit and ground.
Occurrence condition Possible cause
Occurs only when engine is ON.A continuous growling noise occurs. The speed of
the noise varies with changes in the engine speed.• Ignition components
A whistling noise occurs while the engine speed is
high. A booming noise occurs while the engine is
running and the lighting switch is ON.• Generator
The occurrence of the noise is linked with the operation of the fuel pump. • Fuel pump condenser
Noise only occurs when various
electrical components are oper-
ating.A cracking or snapping sound occurs with the op-
eration of various switches.• Relay malfunction, audio unit malfunction
The noise occurs when various motors are operat-
ing.• Motor case ground
•Motor
The noise occurs constantly, not just under certain conditions.• Rear defogger coil malfunction
• Open circuit in printed heater
• Poor ground of antenna amplifier or anten-
na feeder line
A cracking or snapping sound occurs while the vehicle is being driven, especially when
it is vibrating excessively.• Ground wire of body parts
• Ground due to improper part installation
• Wiring connections or a short circuit
Unit Terminals Signal name Fuse No.
Audio unit6 Battery power 31
10 Ignition switch ACC or ON 4
AV switch1 Battery power 31
2 Ignition switch ACC or ON 4
BOSE speaker amp. 1 Battery power 31
Subwoofer 6 Battery power 17

AV-90
< SERVICE INFORMATION >
NAVIGATION SYSTEM
49 – Shield ground – – – –Video display in-
terference.
61 (R/L) GroundIllumination
signalInput ONLighting switch in 1st
positionBattery voltageDisplay unit illu-
mination does
not change
when lighting
switch is turned
to 1st position.- Lighting switch is
OFF3V or less
63 (G/R) Ground Ignition signal Input ON – Battery voltageNavigation cur-
rent location
mark does not
indicate the cor-
rect position.
65 (G/W) GroundReverse
signalInput ONA/T selector lever in
R positionBattery voltageThe navigation
current-location
mark moves
strangely when
the vehicle is
moving back-
wards. A/T selector lever
not in R position0V
66 (W/R) GroundVeh icl e
speed signal
(8-pulse)Input ONWhen vehicle speed
is approx. 40 km/h
(25 MPH)Navigation cur-
rent location
mark does not
indicate the cor-
rect position.
68 – Shield ground – – – – –
69 (L) GroundCommunica-
tion signal (+)Input/
outputON –System does not
work properly.
70 (P) GroundCommunica-
tion signal (–)Input/
outputON –System does not
work properly.
73 74 GPS signal Input ONConnector is not
connected.5VNavigation sys-
tem GPS correc-
tion is not
possible. Te r m i n a l N o .
(Wire color)
ItemSignal
input/
outputCondition
Voltag e
(Approx.)Example of
symptom
+–Igni-
tion
switchOperation
PKIA1935E
SKIA0175E
SKIA0176E