2008 INFINITI FX35 cooling

ATC-70
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
SYSTEM DESCRIPTION
Unified meter and A/C amp. controls compressor operation by ambient temperature, intake air temperature
and signal from ECM.
Low Temperature Protection Control
Unified meter and A/C amp. will turn the compressor ON or OFF as determined by a signal detected by ambi-
ent sensor and intake sensor.
When ambient temperature is higher than −2 °C (28 °F), the compres-
sor turns ON. The compressor turns OFF when ambient temperature
is lower than −5 °C (23 °F).
When intake air temperature is higher than 1 °C (34 °F), the compres-
sor turns ON. The compressor turns OFF when intake air tempera-
ture is lower than −5 °C (23 °F).
DIAGNOSIS PROCEDURE FOR MAGNET CLUTCH
SYMPTOM: Magnet clutch does not engage when A/C switch is ON.
1.CHECK AMBIENT SENSOR AND INTAKE SENSOR CIRCUIT
Check ambient sensor and intake sensor. Refer to ATC-43, "
Self-Diagnosis Function", see No. 9 and 11.
*4 "DIAGNOSIS PROCEDURE FOR
MAGNET CLUTCH" *5
AT C - 7 5 , "Insufficient Cooling"*6AT C - 5 0 , "Operational Check"
*7AT C - 4 3 , "Self-Diagnosis Function",
see No. 4 to 6. *8
AT C - 3 2 , "How to Perform Trouble Di-
agnosis for Quick and Accurate Re-
pair"
RHA094GB
SJIA0267E
SJIA1608E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISATC-75
< SERVICE INFORMATION >
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Insufficient CoolingINFOID:0000000001328191
SYMPTOM: Insufficient cooling
INSPECTION FLOW
*1 AT C - 4 3 , "Self-Diagnosis Function",
see No. 4 to 6. *2
AT C - 5 9 , "Air Mix Door Motor Circuit"*3 "Test Reading"
*4 AT C - 4 3 , "
Self-Diagnosis Function"*5 AT C - 4 3 , "Self-Diagnosis Function",
see No. 13. *6
AT C - 5 4 , "LAN System Circuit"
*7AT C - 6 4 , "Blower Motor Circuit"*8 AT C - 6 9 , "Magnet Clutch Circuit"*9 "PERFORMANCE TEST DIAGNO-
SIS"
SJIA1592E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISATC-79
< SERVICE INFORMATION >
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High-pressure Side is Too High and Low-pressure Side is Too Low
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
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 in-
sufficient. 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 val-
ue quickly drops by approx-
imately 196 kPa (2 kg/cm
2,
28 psi). It then decreases
gradually thereafter. Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure decreas-
es too slowly.).
↓
Air in refrigeration cycle.
Evacuate repeatedly and re-
charge system.
Engine tends to overheat. Engine cooling systems mal-
function. Check and repair each engine
cooling system.
 An area of the low-pressure pipe is colder than areas
near the evaporator outlet.
 Low-pressure pipe is some- times covered with frost.  Excessive liquid refrigerant
on low-pressure side.
 Excessive refrigerant dis- charge flow.
 Expansion valve is open a lit- tle compared with the speci-
fication.
↓
Improper expansion valve ad-
justment. 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 lo-
cated between compressor
and condenser are clogged or
crushed. Check and repair or replace
malfunctioning parts.
 Check lubricant for contami- nation.
AC360A
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 be-
tween high- and low-pressure
sides. Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.
Replace compressor.
AC356A
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISATC-81
< SERVICE INFORMATION >
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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-77
.
 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.
2.CHECK ECV CONTROL SIGNAL
1. Turn ignition switch OFF.
2. Reconnect compressor (ECV) connector.
3. Perform self-diagnosis. Refer to ATC-43, "
Self-Diagnosis Function".
4. Set in self-diagnosis STEP-4 (Code No. 45). Refer to ATC-43, "
Self-Diagnosis Function".
5. Confirm ECV control signal between unified meter and A/C amp. harness connector M57 terminal 45 and ground using an oscillo-
scope.
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 frost-
ed 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 wa-
ter freezes causing a block-
age. Drain water from
refrigerant or replace refrig-
erant.
 If due to foreign particles, re-
move 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
RJIA2295E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISATC-89
< SERVICE INFORMATION >
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Aspirator
The aspirator is located on driver’s side of heater & cooling unit
assembly. It produces vacuum pr
essure due to air discharged from
the heater & cooling unit assembly, continuously taking compartment
air in the aspirator.
DIAGNOSIS PROCEDURE FOR IN-VEHICLE SENSOR
SYMPTOM: In-vehicle sensor circ uit is open or shorted. (22 or −22 is
indicated on unified meter and A/C amp. as a result of performing
self-diagnosis STEP-2.)
1.CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND
1. Disconnect in-vehicle sensor connector.
2. Turn ignition switch ON.
3. Check voltage between in-vehicle sensor harness connector M46 terminal 1 and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2.CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
RJIA0921E
RJIA1804E
RJIA1452E
1 – Ground : Approx. 5 V
RJIA2022E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-94
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
 When checking sunload sensor, select a place where sunshine directly on it.
If NG, replace sunload sensor.
Intake Sensor CircuitINFOID:0000000001328199
COMPONENT DESCRIPTION
Intake Sensor
The intake sensor is located on t he heater & cooling unit assembly. It
converts temperature of air after it passes through the evaporator
into a resistance value which is then input to the unified meter and A/
C amp.
DIAGNOSIS 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 IN TAKE SENSOR AND GROUND
1. Disconnect intake sensor connector.
2. Turn ignition switch ON.
SHA930E
RJIA0928E
RJIA1458E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-108
< SERVICE INFORMATION >
HEATER & COOLING UNIT ASSEMBLY
HEATER & COOLING UNIT ASSEMBLY
Removal and InstallationINFOID:0000000001328211
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Drain coolant from cooling system. Refer to CO-10, "
Changing Engine Coolant" (VQ35DE) or CO-37,
"Changing Engine Coolant" (VK45DE).
3. Remove cowl top cover. Refer to EI-23
.
4. Remove high-pressure pipe 2 mounting clip.
5. Remove low-pressure flexible hose bracket mounting bolt. Refer to ATC-128, "
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 low- pressure pipe 1, 2 and high-
pressure pipe 2, 3 with suitab le material such as vinyl tape
to avoid the entry of air.
7. Remove electric throttle control actuator (VQ35DE). Refer to EM-19
.
8. Disconnect two heater hoses from heater core.
9. Remove instrument panel and pad. Refer to IP-10
.
10. Remove blower unit. Refer to ATC-103
.
RJIA2037E
RJIA2077E
RJIA2041E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

HEATER & COOLING UNIT ASSEMBLYATC-109
< SERVICE INFORMATION >
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11. Remove mounting nuts and bolts, and then remove instrument stays (left and right side).
12. Remove mounting bolts from heater & cooling unit assembly.
13. Disconnect drain hose.
14. Remove center and side ventilator ducts, defroster nozzle and side defroster ducts. Refer to ATC-116,
"Removal and Installation".
15. Remove steering column mounting bolts and nut.
16. Remove steering member mounting bolts, nut and harness clips.
17. Remove steering member, and then remove heater & cooling unit assembly.
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:
 Replace O-rings of low-pressure pipe 1 and high- pressure pipe 2 with new ones, and then apply
compressor oil to it when installing it.
 Female-side piping c onnection 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 comple ted, pull male-side piping by hand to make sure that connection
does not come loose.
 When recharging refrigerant, check for leaks.
RJIA2042E
SJIA1223E
SJIA1656E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C