Pressure INFINITI FX35 2006 Service Manual

TROUBLE DIAGNOSIS ATC-95
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Revision: 2006 December 2006 FX35/FX45
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. The pressure returns to nor-
mal 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.

Low-pressure pipe is
sometimes covered 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

ATC-96
TROUBLE DIAGNOSIS
Revision: 2006 December 2006 FX35/FX45
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-156, "
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 2 , "
Intake
Sensor Circuit" .

Replace compressor.

Repair evaporator fins.

Replace evaporator.

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

TROUBLE DIAGNOSIS ATC-97
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Revision: 2006 December 2006 FX35/FX45
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 and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 10A fuse [No. 12, located in the fuse block (J/B)]. Refer to PG-81, "
FUSE
BLOCK - JUNCTION BOX (J/B)" .

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

If fuse is NG, check harness for short circuit and replace fuse.
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 wet with dew. 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

ATC-106
TROUBLE DIAGNOSIS
Revision: 2006 December 2006 FX35/FX45
In-vehicle Sensor CircuitNJS000EG
COMPONENT DESCRIPTION
In-vehicle Sensor
The in-vehicle sensor is located on instrument driver lower panel. It
converts variations in temperature of compartment air drawn from
the aspirator into a resistance value. It is then input into the unified
meter and A/C amp.
Aspirator
The aspirator is located on driver’s side of heater & cooling unit
assembly. It produces vacuum pressure due to air discharged from
the heater & cooling unit assembly, continuously taking compartment
air in the aspirator.
RJIA2021E
RJIA0921E
RJIA1804E

INTAKE SENSOR ATC-119
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Revision: 2006 December 2006 FX35/FX45
INTAKE SENSORPFP:27723
Removal and InstallationNJS000EO
REMOVAL
1. Remove low-pressure pipe 2 and high-pressure pipe 3. Refer to ATC-150, "Removal and Installation of
Low-pressure Pipe 2 and High-pressure Pipe 3" .
CAUTION:
Cap or wrap the joint of the pipe with suitable material such as vinyl tape to avoid the entry of air.
2. Slide evaporator to passenger side, and then remove intake sensor.
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:

Replace O-rings of A/C piping with new ones, and then apply compressor oil to it when installing
it.

Mark the mounting position of intake sensor bracket prior to removal so that the reinstalled sen-
sor can be located in the same position.

Female-side piping connection is thin and easy to deform. slowly insert the male-side piping
straight in axial direction.

Insert piping securely until a click is heard.

After piping connection is completed, pull male-side piping by hand to make sure that connection
does not come loose.

When recharging refrigerant, check for leaks.
RJIA0928E

HEATER & COOLING UNIT ASSEMBLY ATC-125
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Revision: 2006 December 2006 FX35/FX45
HEATER & COOLING UNIT ASSEMBLYPFP:27110
Removal and InstallationNJS000EU
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Drain coolant from cooling system. Refer to CO-11, "
Changing Engine Coolant" (VQ35DE) or CO-38,
"Changing Engine Coolant" (VK45DE).
3. Remove cowl top cover. Refer to EI-23, "
COWL TOP" .
4. Remove high-pressure pipe 2 mounting clip.
5. Remove low-pressure flexible hose bracket mounting bolt. Refer to ATC-146, "
Removal and Installation of
Low-pressure Flexible Hose" .
6. Disconnect low-pressure pipe 1 and high-pressure pipe 2 from evaporator.
a. Set a disconnector [high-pressure side (SST: 9253089908), low- pressure side (SST: 9253089916)] on A/C piping.
b. Slide a disconnector toward vehicle front until it clicks.
c. Slide A/C piping toward vehicle front and disconnect it.
CAUTION:
Cap or wrap the joint of the pipe with suitable material such
as vinyl tape to avoid the entry of air.
7. Remove electric throttle control actuator (VQ35DE). Refer to EM-19, "
INTAKE MANIFOLD COLLECTOR" .
8. Disconnect two heater hoses from heater core.
9. Remove instrument panel assembly. Refer to IP-10, "
INSTRUMENT PANEL ASSEMBLY" .
10. Remove blower unit. Refer to ATC-120, "
BLOWER UNIT" .
RJIA2037E
RJIA2041E
RJIA2077E

HEATER & COOLING UNIT ASSEMBLY ATC-129
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Revision: 2006 December 2006 FX35/FX45
19. Insulator 20. Heater case (right) 21. Low-pressure pipe 2
22. High-pressure pipe 3 23. Expansion valve 24. Evaporator
25. Heater case (left) 26. Foot duct (left) 27. Center case
28. Max. cool door (left) 29. Ventilator door 30. Side link
31. Mode door motor 32. Defroster door 33. Max. cool door (right)
34. Defroster door lever 35. Defroster door link

REFRIGERANT LINES ATC-141
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Revision: 2006 December 2006 FX35/FX45
VK45DE
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Remove air cleaner case and air duct. Refer to EM-17, "
AIR CLEANER AND AIR DUCT" (VQ35DE) or
EM-177, "
AIR CLEANER AND AIR DUCT" (VK45DE).
3. Remove front engine undercover, using power tools.
4. Remove cooling fan shroud (lower). Refer to CO-41, "
RADIATOR" (VK45DE).
5. Remove mounting nuts from low-pressure flexible hose and high-pressure flexible hose.
CAUTION:
Cap or wrap the joint of the pipe with suitable material such
as vinyl tape to avoid the entry of air.
6. Remove high-pressure flexible hose. Refer to ATC-147,
"Removal and Installation of High-pressure Flexible Hose"
(VK45DE).
7. Disconnect compressor connector.
8. Remove A/C compressor belt. Refer to EM-15, "
DRIVE BELTS" (VQ35DE) or EM-174, "DRIVE BELTS"
(VK45DE).
RJIA2244E
RJIA2059E
RJIA2058E

ATC-142
REFRIGERANT LINES
Revision: 2006 December 2006 FX35/FX45
9. Disconnect compressor (ECV) connector.
10. Remove mounting bolts from compressor, using power tools.
11. Remove compressor downward of the vehicle.
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:

Replace O-rings of low-pressure flexible hose, high-pressure pipe and high-pressure flexible hose
with new ones, and then apply compressor oil to it when installing it.

When recharging refrigerant, check for leaks.
Removal and Installation of Compressor ClutchNJS000F3
REMOVAL
Overhaul
1. When removing center bolt, hold clutch disc with a clutch disc wrench (SST).
2. Remove clutch disc using a clutch disc puller (SST).
RJIA2061E
RJIA2060E
RHA136EB
RHA399F

ATC-146
REFRIGERANT LINES
Revision: 2006 December 2006 FX35/FX45
Removal and Installation of Low-pressure Flexible HoseNJS000F4
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Remove the air cleaner case and air duct. Refer to EM-17, "
AIR CLEANER AND AIR DUCT" (VQ35DE)
or EM-177, "
AIR CLEANER AND AIR DUCT" (VK45DE).
3. Remove low-pressure flexible hose bracket mounting bolt.
4. Disconnect one-touch joint between low-pressure flexible hose and low-pressure pipe 1.
a. Set a disconnector (SST: 9253089916) on A/C piping.
b. Slide a disconnector toward vehicle front until it clicks.
c. Slide A/C piping toward vehicle front and disconnect it. CAUTION:
Cap or wrap the joint of the pipe with suitable material such
as vinyl tape to avoid the entry of air.
5. Remove mounting nut from low-pressure flexible hose.
6. Remove mounting nut, and then remove low-pressure pipe (VK45DE).
7. Remove low-pressure flexible hose. CAUTION:
Cap or wrap the joint of the pipe with suitable material such as vinyl tape to avoid the entry of air.
RJIA2062E
RJIA2069E
RJIA2064E
RJIA2063E