air INFINITI FX35 2005 Service Manual

TROUBLE DIAGNOSIS ATC-89
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Revision: 2005 July 2005 FX
11 . CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (FAN ON SIGNAL)
1. Reconnect BCM connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Check voltage between unified meter and A/C amp. harness connector M57 terminal 57 (BR/Y) and ground.
OK or NG
OK >> GO TO 12.
NG-1 >> If the voltage is approx. 5 V when blower motor is ON: Replace unified meter and A/C amp.
NG-2 >> If the voltage is approx. 0 V when blower motor is OFF: Replace BCM. Refer to BCS-16,
"Removal and Installation of BCM" .
12. CHECK CAN COMMUNICATION
Check CAN communication. Refer to BCS-15, "
CAN Communication Inspection Using CONSULT-II (Self-
Diagnosis)" .

BCM – ECM

ECM – IPDM E/R

ECM – Unified meter and A/C amp.
OK or NG
OK >> INSPECTION END
NG >> Repair or replace malfunctioning part(s).
Te r m i n a l s
Condition Voltage
(+)
(-)
Unified meter
and A/C amp. connector Terminal No.
(wire color)
M57 57 (BR/Y) Ground A/C switch: ON
(Blower motor operates.) Approx. 0 V
OFF switch: ON
(A/C system: OFF) Approx. 5 V
RJIA2010E

ATC-92
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
*1ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 4 to 6. *2
ATC-73, "
Air Mix Door Motor Circuit"*3ATC-95, "Test Reading"
*4 ATC-59, "AUXILIARY MECHA-
NISM: TEMPERATURE SETTING
TRIMMER"
*5ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13. *6
ATC-66, "
LAN System Circuit"
*7 ATC-79, "Blower Motor Circuit"*8ATC-84, "Magnet Clutch Circuit"*9ATC-93, "PERFORMANCE TEST
DIAGNOSIS"
*10 ATC-61, "Operational Check"*11AT C - 7 , "CONTAMINATED REFRIG-
ERANT"
*12EM-15, "Checking Drive Belts"
(VQ35DE) or EM-173, "
Checking
Drive Belts" (VK45DE)
*13 EC-467, "
SYSTEM DESCRIPTION"
(VQ35DE) or EC-1213, "
SYSTEM
DESCRIPTION" (VK45DE)

TROUBLE DIAGNOSIS ATC-93
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Revision: 2005 July 2005 FX
PERFORMANCE TEST DIAGNOSIS
*1AT C - 9 5 , "PERFORMANCE CHART"*2ATC-95, "PERFORMANCE CHART"*3 AT C - 9 6 , "TROUBLE DIAGNOSIS
FOR UNUSUAL PRESSURE"
*4AT C - 7 3 , "Air Mix Door Motor Circuit"
SJIA1226E

TROUBLE DIAGNOSIS ATC-95
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Revision: 2005 July 2005 FX
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 condition Indoors or in the shade (in a well-ventilated place)
Doors Closed
Door windows Open
Hood Open
TEMP. Max. COLD
Mode switch (Ventilation) set
Recirculation (REC) switch (Recirculation) set
Fan (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) 11.2 - 13.2 (52 - 56)
25 (77) 12.2 - 14.8 (54 - 59)
30 (86) 15.5 - 18.6 (60 - 65)
35 (95) 21.0 - 24.5 (70 - 76)
40 (104) 28.7 - 32.6 (84 - 91)
60 - 70 20 (68) 13.2 - 15.2 (56 - 59)
25 (77) 14.8 - 17.3 (59 - 63)
30 (86) 18.6 - 21.6 (65 - 71)
35 (95) 24.5 - 28.0 (76 - 82)
40 (104) 32.6 - 36.5 (91 - 98)
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)
961 - 1,167
(9.8 - 11.9, 139 - 169) 216 - 265
(2.2 - 2.7, 31 - 38)
25 (77) 1,108 - 1,353
(11.3 - 13.8, 161 - 196) 230 - 281
(2.3 - 2.9, 33 - 41)
30 (86) 1,275 - 1,549
(13.0 - 15.8, 185 - 225) 261 - 320
(2.7 - 3.3, 38 - 46)
35 (95) 1,549 - 1,893
(15.8 - 19.3, 225 - 274) 297 - 364
(3.0 - 3.7, 43 - 53)
40 (104) 1,814 - 2,216
(18.5 - 22.6, 263 - 321) 357 - 435
(3.6 - 4.4, 52 - 63)

ATC-96
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
TROUBLE DIAGNOSIS FOR UNUSUAL PRESSURE
Whenever system’s high and/or low side pressure(s) is/are unusual, diagnose using a manifold gauge. The
marker above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the
standard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air tempera-
ture-to-operating pressure table).
Both High- and Low-pressure Sides are Too High
High-pressure Side is Too High and Low-pressure Side is Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too high. Pressure is reduced soon
after water is splashed on
condenser. Excessive refrigerant charge
in refrigeration cycle. Reduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is
insufficient. Insufficient condenser cooling
performance.
↓
1. Condenser fins are clogged.
2. Improper fan rotation of cooling fan.

Clean condenser.

Check and repair cooling fan
as necessary.

Low-pressure pipe is not
cold.

When compressor is
stopped high-pressure
value quickly drops by
approximately 196 kPa (2
kg/cm
2 , 28 psi). It then
decreases gradually there-
after. Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure
decreases too slowly.)
↓
Air in refrigeration cycle. Evacuate repeatedly and
recharge system.
Engine tends to overheat. Engine cooling systems mal-
function. Check and repair each engine
cooling system.

An area of the low-pres-
sure pipe is colder than
areas near the evaporator
outlet.

Plates are sometimes cov-
ered with frost.

Excessive liquid refrigerant
on low-pressure side.

Excessive refrigerant dis-
charge flow.

Expansion valve is open a
little compared with the
specification.
↓
Improper expansion valve
adjustment. Replace expansion valve.
AC359A
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too high and
low-pressure side is too low.
Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot. High-pressure tube or parts
located between compressor
and condenser are clogged or
crushed.

Check and repair or replace
malfunctioning parts.

Check lubricant for contami-
nation.
AC360A

TROUBLE DIAGNOSIS ATC-97
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Revision: 2005 July 2005 FX
High-pressure Side is Too Low and Low-pressure Side is Too High
Both High- and Low-pressure Sides are Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too low and
low-pressure side is too high. High- and low-pressure sides
become equal soon after com-
pressor operation stops. Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings. Replace compressor.
No temperature difference
between high- and low-pres-
sure sides. Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings. Replace compressor.
AC356A
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 lubricant for contami-
nation.

Temperature of expansion
valve inlet is extremely low
as compared with areas
near liquid tank.

Expansion valve inlet may
be frosted.

Temperature difference
occurs somewhere in high-
pressure side. High-pressure pipe located
between liquid tank and
expansion valve is clogged.

Check and repair malfunc-
tioning parts.

Check lubricant for contami-
nation.
Expansion valve and liquid
tank are warm or slightly cool
when touched. Low refrigerant charge.
↓
Leaking fittings or compo-
nents. Check refrigerant for leaks.
Refer to ATC-158, "
Checking
for 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.

Replace expansion valve.

Check lubricant for contami-
nation.
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 lubricant for contami-
nation.
Air flow volume is not enough
or is too low. Evaporator is frozen.

Check intake sensor circuit.
Refer to AT C - 11 3 , "
Intake
Sensor Circuit" .

Replace compressor.

Repair evaporator fins.

Replace evaporator.

Refer to AT C - 7 9 , "Blower
Motor Circuit" .
AC353A

ATC-98
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
DIAGNOSIS PROCEDURE FOR INSUFFICIENT COOLING
SYMPTOM: Insufficient cooling
1. CHECK POWER SUPPLY FOR ECV (ELECTRONIC CONTROL VALVE)
1. Disconnect compressor (ECV) connector.
2. Turn ignition switch ON.
3. Check voltage between compressor (ECV) harness connector F6 terminal 2 (G) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 10 A fuse [No. 12, located in the fuse block (J/B)]. Refer to PG-82, "
FUSE
BLOCK - JUNCTION BOX (J/B)" .

If fuse is OK, check harness for open circuit. Repair or replace if necessary.

If fuse is NG, replace fuse and check harness for short circuit. Repair or replace if necessary.
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
2 – ground : Battery voltage
RJIA2294E

TROUBLE DIAGNOSIS ATC-99
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Revision: 2005 July 2005 FX
2. CHECK ECV CONTROL SIGNAL
1. Turn ignition switch OFF.
2. Reconnect compressor (ECV) connector.
3. Perform self-diagnosis. Refer to AT C - 5 3 , "
Self-diagnosis Func-
tion" .
4. Set in self-diagnosis STEP-4 (Code No. 45). Refer to AT C - 5 4 ,
"FUNCTION CONFIRMATION PROCEDURE" .
5. Confirm ECV control signal between unified meter and A/C amp. harness connector M57 terminal 45 (PU/W) and ground using
an oscilloscope.
OK or NG
OK >> Replace compressor.
NG >> GO TO 3.
3. CHECK CIRCUIT CONTINUITY BETWEEN ECV AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect compressor (ECV) and unified meter and A/C amp. connector.
3. Check continuity between compressor (ECV) harness connector F6 terminal 3 (PU) and unified meter and A/C amp. harness
connector M57 terminal 45 (PU/W).
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK ECV
Check continuity between compressor (ECV) connector F6 terminals
2 and 3.
OK or NG
OK >> Replace unified meter and A/C amp.
NG >> Replace compressor.
RJIA2295E
RJIA1475E
3 – 45 : Continuity should exist.
RJIA2296E
2 – 3 : Continuity should exist.
RJIA2297E

ATC-100
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Insufficient HeatingAJS00150
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-61, "Operational Check"*2AT C - 7 3 , "Air Mix Door Motor Circuit"*3ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 4 to
6.
*4 ATC-54, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13. *5
AT C - 6 6 , "
LAN System Circuit"*6ATC-79, "Blower Motor Circuit"
*7 EC-208, "DTC P0117, P0118 ECT
SENSOR" (VQ35DE) or EC-914,
"DTC P0117, P0118 ECT SEN-
SOR" (VK45DE) *8
CO-11, "
Changing Engine Coolant"
(VQ35DE) or CO-37, "
Changing
Engine Coolant" (VK45DE) *9
CO-15, "
Checking Radiator Cap"
(VQ35DE) or CO-43, "
Checking
Radiator Cap" (VK45DE)
RJIA2013E

ATC-102
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Self-diagnosisAJS00152
SYMPTOM: Self-diagnosis cannot be performed.
INSPECTION FLOW
*1 Compressor Clutch, ATC-144,
"REMOVAL"
*2 Compressor Clutch, ATC-146,
"INSTALLATION"
*3AT C - 2 7 , "Maintenance of Lubricant
Quantity in Compressor"
*4ATC-61, "Operational Check"*5 EM-15, "Checking Drive Belts"
(VQ35DE) or EM-173, "
Checking
Drive Belts" (VK45DE)
*1 ATC-63, "
Power Supply and Ground
Circuit for Auto Amp."
*2 ATC-104, "Ambient Sensor Circuit"*3ATC-107, "In-vehicle Sensor Circuit"
*4ATC-110, "Sunload Sensor Circuit"*5 ATC-113, "Intake Sensor Circuit"*6AT C - 7 3 , "Air Mix Door Motor Circuit"
*7ATC-61, "Operational Check"*8 ATC-42, "SYMPTOM TABLE"
RJIA2014E