2004 INFINITI FX35 cooling

TROUBLE DIAGNOSIS
ATC-91
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Revision: 2004 November 2004 FX35/FX45
Insufficient CoolingAJS0014Z
SYMPTOM: Insufficient cooling
INSPECTION FLOW
RJIA3005E

ATC-96
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 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.Pressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge
in refrigeration cycleReduce 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 cycleEvacuate 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
adjustmentReplace 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-98
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
DIAGNOSTIC 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 harness connector F6 ter-
minal 2 (G) 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-83, "
FUSE
BLOCK - JUNCTION BOX (J/B)" .
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-107
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Revision: 2004 November 2004 FX35/FX45
In-vehicle Sensor CircuitAJS00155
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. It
produces vacuum pressure due to air discharged from the heater &
cooling unit, continuously taking compartment air in the aspirator.
RJIA2021E
RJIA0921E
RJIA1804E

TROUBLE DIAGNOSIS
ATC-113
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Revision: 2004 November 2004 FX35/FX45
Intake Sensor CircuitAJS00157
COMPONENT DESCRIPTION
Intake Sensor
The intake sensor is located on the heater & cooling unit. It converts
temperature of air after it passes through the evaporator into a resis-
tance value which is then input to the unified meter and A/C amp.
DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR
SYMPTOM: Intake sensor circuit is open or shorted. (24 or −24 is
indicated on unified meter and A/C amp. as a result of performing
Self-diagnosis STEP-2.)
1. CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND
1. Disconnect intake sensor connector.
2. Turn ignition switch ON.
3. Check voltage between intake sensor harness connector M254
terminal 2 (R) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2. CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between intake sensor harness connector
M254 terminal 1 (W) and unified meter and A/C amp. harness
connector M57 terminal 49 (W/G).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
RJIA0928E
RJIA1458E
2 – Ground : Approx. 5V
RJIA2031E
1 – 49 : Continuity should exist.
RJIA2032E

ATC-126
HEATER & COOLING UNIT ASSEMBLY
Revision: 2004 November 2004 FX35/FX45
HEATER & COOLING UNIT ASSEMBLYPFP:27110
Removal and InstallationAJS0015J
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge refrigerant.
2. Drain coolant from cooling system. Refer to CO-11, "
Changing Engine Coolant" (VQ35DE) or CO-36,
"Changing Engine Coolant" (VK45DE).
3. Remove cowl top cover. Refer to EI-24, "
COWL TOP" .
4. Remove high-pressure pipe 2 mounting clip.
5. Remove low-pressure flexible hose bracket mounting bolts.
6. Disconnect evaporator-side one touch joint.
a. Set a disconnector (High-pressure side: 92530-89908, Low-
pressure side: 92530-89916) 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:
Seal connection opening of piping with a cap or vinyl tape
to avoid exposure to atmosphere.
7. Remove electronic control throttle assembly (VQ35DE). Refer to
EM-19, "
INTAKE MANIFOLD COLLECTOR" .
8. Disconnect two heater hoses from heater core.
9. Remove instrument panel assembly. Refer to IP-11, "
Removal
and Installation" .
10. Remove blower unit. Refer to ATC-121, "
BLOWER UNIT" .
11. Remove instrument stays (driver side and passenger side).
RJIA2037E
RJIA2041E
RJIA2077E
RJIA2042E

HEATER & COOLING UNIT ASSEMBLY
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Revision: 2004 November 2004 FX35/FX45
12. Remove mounting bolts from heater & cooling unit.
13. Disconnect drain hose.
14. Remove ventilator ducts, defroster nozzle and ducts.
15. Remove steering member mounting bolts, nut and harness clips.
16. Remove the steering member, and then remove heater & cooling unit.
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:

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

Connection point for female-side piping is thin. So, when inserting male-side piping, take care not
to deform female-side piping. Slowly insert in axial direction.

Insert one-touch joint connection point securely until it clicks.

After piping has been connected, pull male-side piping by hand to make sure piping does not
come off.

When recharging refrigerant, check for leaks.
NOTE:

When filling radiator with coolant, refer to CO-11, "Changing Engine Coolant" (VQ35DE) or CO-36,
"Changing Engine Coolant" (VK45DE).

Recharge the refrigerant.
RJIA2044E
RJIA2043E
Heater & cooling unit mounting bolt
Tightening torque : 6.8 N·m (0.69 kg-m, 60 in - lb)
Steering member mounting nut and bolt
Tightening torque : 12 N·m (1.2 kg-m, 9 ft - lb)

ATC-128
HEATER & COOLING UNIT ASSEMBLY
Revision: 2004 November 2004 FX35/FX45
Disassembly and AssemblyAJS0015K
1. Heater pipe grommet 2. Heater core 3. Heater pipe cover
4. Aspirator 5. Aspirator hose 6. Air mix door motor (driver side)
7. Air mix door (slide door) 8. Max. cool door link 9. Max. cool door lever
10. Ventilator door lever 11. Ventilator door link 12. Air mix door motor (passenger side)
13. Intake sensor bracket 14. Intake sensor 15. Foot duct (right)
16. Evaporator cover 17. Evaporator cover adaptor 18. Heater pipe bracket
RJIA2045E