2008 INFINITI FX35 cooling system

TROUBLE DIAGNOSISATC-79
< SERVICE INFORMATION >
C
DE
F
G H
I
K L
M A
B
AT C
N
O P
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 >
C
DE
F
G H
I
K L
M A
B
AT C
N
O P
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

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

ATC-140
< SERVICE INFORMATION >
REFRIGERANT LINES
2. When testing, circle each fitting completely with probe.
3. Move probe along component approximately 25 to 50 mm (1 to2 in)/sec.
CHECKING PROCEDURE
To prevent inaccurate or false readings, make sure t here is no refrigerant vapor, shop chemicals, or cigarette
smoke in the vicinity of the vehicle. Perform the leak test in calm area (low air/wind movement) so that the
leaking refrigerant is not dispersed.
1. Stop the engine.
2. Connect a suitable A/C manifold gauge set (SST: J-39183) to the A/C service valves.
3. Check if the A/C refrigerant pressu re is at least 345 kPa (3.52 kg/cm
2, 50 psi) above 16°C (61 °F). If less
than specification, recover/evacuate and recharge t he system with the specified amount of refrigerant.
NOTE:
At temperatures below 16 °C (61 °F), leaks may not be detected since the system may not reach 345 kPa
(3.52 kg/cm
2, 50 psi).
4. Perform the leak test from the high-pressure side (compressor discharge a to evaporator inlet h) to the
low-pressure side [evaporator drain hose i to shaft seal o (VK45DE) or n (VQ35DE)]. Refer to ATC-121,
"Component". Perform a leak check for the following areas carefully. Clean the component to be checked
and move the leak detected probe comp letely around the connection/component.
Compressor
Check the fitting of high- and low-pressure flexible hoses, relief valve and shaft seal.
Condenser
Check the fitting of high-pressure flexible hose and pipe, refrigerant pressure sensor.
Liquid tank
Check the fitting of refrigerant connection.
Service valves
Check all around the service valves. Ensure service va lve caps are secured on the service valves (to pre-
vent leaks).
NOTE:
After removing A/C manifold gauge set from service va lves, wipe any residue from valves to prevent any
false readings by leak detector.
Cooling unit (Evaporator)
With engine OFF, turn blower fan on “High” for at leas t 15 seconds to dissipate any refrigerant trace in the
cooling unit. Wait a minimum of 10 minutes accumulation time (refer to the manufacturer’s recommended
procedure for actual wait time) before inserti ng the leak detector probe into the drain hose.
Keep the probe inserted for at least 10 seconds. Use c aution not to contaminate the probe tip with water
or dirt that may be in the drain hose.
5. If a leak detector detects a leak, verify at least once by blowing compressed air into area of suspected
leak, then repeat check as outlined above.
SHA706E
SHA708EA
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

CO-1
ENGINE
C
DE
F
G H
I
J
K L
M
SECTION CO
A
CO
N
O P
CONTENTS
ENGINE COOLING SYSTEM
VQ35DE
SERVICE INFORMATION .. ..........................
3
PRECAUTIONS .............................................. .....3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
3
Precaution for Liquid Gasket .....................................3
PREPARATION ...................................................5
Special Service Tool ........................................... ......5
Commercial Service Tool ..........................................5
OVERHEATING CAUSE ANALYSIS ..................7
Troubleshooting Chart ......................................... ......7
COOLING SYSTEM ....................................... .....9
Cooling Circuit ..................................................... ......9
System Chart ............................................................9
ENGINE COOLANT ...........................................10
Inspection ............................................................ ....10
Changing Engine Coolant .......................................10
RADIATOR .........................................................13
Component .......................................................... ....13
Removal and Installation .........................................13
Checking Radiator Cap ...........................................14
Checking Radiator ...................................................15
RADIATOR (ALUMINUM TYPE) ........................16
Component .......................................................... ....16
Disassembly and Assembly ....................................16
COOLING FAN ...................................................20
Component .......................................................... ....20
Removal and Installation .........................................20
Disassembly and Assembly ....................................20
WATER PUMP ...................................................22
Component .......................................................... ....22
Removal and Installation .........................................22
WATER INLET AND THERMOSTAT ASSEM-
BLY ....................................................................
27
Component .......................................................... ....27
Removal and Installation .........................................27
WATER OUTLET AND WATER PIPING ..........29
Component ..............................................................29
Removal and Installation .........................................29
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
31
Standard and Limit ..................................................31
VK45DE
SERVICE INFORMATION .. .........................
32
PRECAUTIONS .................................................32
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ....
32
PREPARATION .................................................33
Special Service Tool ................................................33
Commercial Service Tool ........................................33
OVERHEATING CAUSE ANALYSIS ................34
Troubleshooting Chart .............................................34
COOLING SYSTEM ..........................................36
Cooling Circuit .........................................................36
System Chart ...........................................................36
ENGINE COOLANT ..........................................37
Inspection ................................................................37
Changing Engine Coolant ........................................37
RADIATOR ....................................... .................40
Component .......................................................... ....40
Removal and Installation .........................................40
Checking Radiator Cap ...........................................42
Checking Radiator ...................................................43
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

OVERHEATING CAUSE ANALYSISCO-7
< SERVICE INFORMATION > [VQ35DE]
C
D
E
F
G H
I
J
K L
M A
CO
NP
O
OVERHEATING CAUSE ANALYSIS
Troubleshooting ChartINFOID:0000000001325842
Symptom Check items
Cooling sys-
tem parts
malfunction Poor heat transfer
Water pump malfunction Worn or loose drive belt
—
Thermostat stuck closed —
Damaged fins
Dust contamination or pa-
per clogging
Physical damage
Clogged radiator cooling
tube Excess foreign material
(rust, dirt, sand, etc.)
Reduced air flow Cooling fan does not oper-
ate
Fan assembly —
High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud — — —
Improper engine coolant
mixture ratio ———
Poor engine coolant quality — Engine coolant density —
Insufficient engine coolant Engine coolant leaks Cooling hose
Loose clamp
Cracked hose
Water pump Poor sealing
Radiator cap Loose
Poor sealing
Radiator O-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tank Exhaust gas leaks into cool-
ing systemCylinder head deterioration
Cylinder head gasket deteri-
oration
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

COOLING SYSTEMCO-9
< SERVICE INFORMATION > [VQ35DE]
C
D
E
F
G H
I
J
K L
M A
CO
NP
O
COOLING SYSTEM
Cooling CircuitINFOID:0000000001325843
System ChartINFOID:0000000001325844
PBIC2073E
PBIC0847E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

CO-10
< SERVICE INFORMATION >[VQ35DE]
ENGINE COOLANT
ENGINE COOLANT
InspectionINFOID:0000000001325845
LEVEL CHECK
 Check if the reservoir tank engine coolant level is within the “MIN”
to “MAX” when the engine is cool.
 Adjust the engine coolant level as necessary.
LEAK CHECK
 To check for leaks, apply pressure to the cooling system with the
radiator cap tester (commercial service tool) (A) and radiator cap
tester adapter (commercial service tool) (B).
WARNING:
Do not remove radiator cap when engine is hot. Serious burns
could occur from high-pressure engine coolant escaping from
radiator.
CAUTION:
Higher test pressure than speci fied may cause radiator damage.
NOTE:
In a case that engine coolant decreases, replenish radiator with engine coolant.
 If anything is found, repair or replace damaged parts.
Changing Engine CoolantINFOID:0000000001325846
WARNING:
 To avoid being scalded, do not change en gine coolant when the engine is hot.
 Wrap a thick cloth around radiator cap and carefully remove radiator cap. First, turn radiator cap a
quarter of a turn to release built-up pressu re. Then turn radiator cap all the way.
DRAINING ENGINE COOLANT
1. Remove front engine undercover with power tool.
2. Open radiator drain plug at the bottom of radiator, and then
remove radiator cap.
When draining all of engine cool ant in the system, open water drai n plugs on cylinder block. Refer
to EM-123, "
Disassembly and Assembly".
SMA412B
Testing pressure
: 157 kPa (1.6 kg/cm
2, 23 psi)
PBIC5121J
SBIA0444E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C