2008 INFINITI FX35 hot

TROUBLE DIAGNOSISATC-61
< SERVICE INFORMATION >
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 Sunload sensor
 Intake sensor
System Operation
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends air mix door, mode door and intake door motor opening angle data to the air mix door motor LCUs,
mode door motor LCU and intake door motor LCU.
The air mix door motors, mode door motor and intake door motor read their respective signals according to the
address signal. Opening angle indication signals receiv ed from the unified meter and A/C amp. and each of
the motor position sensors are compared by the LCUs in each door motor with the existing decision and open-
ing angles. Subsequently, HOT/COLD, DEF/VENT and FRE/REC operation is selected. The new selection
data are returned to the unified meter and A/C amp.
Air Mix Door Control Specification
COMPONENT DESCRIPTION
Air Mix Door Motor
The air mix door motors are attached to the heater & cooling unit
assembly. It rotates so that the air mix door is opened or closed to a
position set by the unified meter and A/C amp. Motor rotation is then
conveyed through a shaft and the air mix door position feedback is
then sent to the unified meter and A/C amp. by PBR built-in air mix
door motor.
RJIA1781E
RJIA1782E
RJIA0893E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-66
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
 Intake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calculated by the unified meter and A/C amp. based on the
input from the PBR, in-vehicle sensor, sunl oad sensor, intake sensor and ambient sensor.
When the air flow is increased, the duty ratio of the blower fan motor’s drive signal is changed at 8%/sec. to
prevent a sudden increase in air flow.
In addition to manual air flow control and the usual automat ic air flow control, starting air flow control, low
water temperature starting control and high passenger co mpartment temperature starting control are avail-
able.
Starting Fan Speed Control
Start up from COLD SOAK Condition (Automatic mode)
In a cold start up condition where the engine coolant temperature is below 56 °C (133 °F), the blower will not
operate for a short period of time (up to 150 seconds ). The exact start delay time varies depending on the
ambient and engine coolant temperature.
In the most extreme case (very low ambient) the blower starting delay will be 150 seconds as described
above. After this delay, the blower will operate at lo w speed until the engine coolant temperature rises above
56 °C (133 °F), and then the blower speed will increase to the objective speed.
Start up from usual or HOT SOAK Condition (Automatic mode)
The blower will begin operation momentarily after the AU TO switch is pressed. The blower speed will gradu-
ally rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
Blower Speed Compensation
Sunload
When the in-vehicle temperature and the set temperature are very close, the blower will be operating at low
speed. The low speed will vary depending on the sunload. Du ring conditions of low or no sunload, the blower
speed is at duty ratio 25%. During high sunload conditi ons, the unified meter and A/C amp. raise the blower
speed (duty ratio 49%).
Fan Speed Control Specification
RJIA1995E
RJIA1996E
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-91
< SERVICE INFORMATION >
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After disconnecting in-vehicle sensor connector M46, measure resis-
tance between terminals 1 and 2 at sensor side. Refer to the table
below.
If NG, replace in-vehicle sensor.
Sunload Sensor CircuitINFOID:0000000001328198
COMPONENT DESCRIPTION
Sunload Sensor
The sunload sensor is located on the passenger’s side front
defroster grille. It detects sunload entering through windshield by
means of a photo diode. The sensor converts the sunload into a cur-
rent value which is then input into the unified meter and A/C amp.
SUNLOAD INPUT PROCESS
The unified meter and A/C amp. also includes a processi ng circuit which averages the variations in detected
sunload over a period of time. This prevents drastic swings in the ATC system operation due to small or quick
variations in detected sunload.
For example, consider driving along a road bordered by an occasional group of large trees. The sunload
detected by the sunload sensor will vary whenever the tr ees obstruct the sunlight. The processing circuit aver-
ages the detected sunload over a period of time, so that the (insignificant) effect of the trees momentarily
obstructing the sunlight does not cause any change in t he ATC system operation. On the other hand, shortly
after entering a long tunnel, the system will recognize t he change in sunload, and the system will react accord-
ingly.
DIAGNOSIS PROCEDURE FOR SUNLOAD SENSOR
Temperature °C ( °F) Resistance k Ω
− 15 (5) 12.73
− 10 (14) 9.92
− 5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27 45 (113) 1.07
RJIA2025E
RJIA2026E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

BL-210
< SERVICE INFORMATION >
BODY REPAIR
2. Do not undercoat the exhaust pipe or other parts which become hot.
3. Do not undercoat rotating parts.
4. Apply bitumen wax after applying undercoating.
5. After putting seal on the vehicle, put undercoating on it.
STONE GUARD COAT
To prevent damage caused by stones, the lower outer body panel (fender, door, etc.) have an additional layer
of Stone Guard Coating over the ED primer coating. When replacing or repairing these panels, apply Stone
SIIA2252E
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

RADIATORCO-13
< SERVICE INFORMATION > [VQ35DE]
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RADIATOR
ComponentINFOID:0000000001325847
 Refer to
GI-8, "Component" for symbols in the figure.
Removal and InstallationINFOID:0000000001325848
REMOVAL
WARNING:
Do not remove radiator cap when en gine is hot. Serious burns could occur from high-pressure engine
coolant escaping from radiator. Wrap a thick cloth aroun d the cap. Slowly turn it a quarter of a turn to
release built-up pressure. Carefully remove ra diator cap by turning it all the way.
1. Remove front engine undercover with power tool.
2. Drain engine coolant from radiator. Refer to CO-10, "
Changing Engine Coolant".
CAUTION:
 Perform this step when the engine is cold.
 Do not spill engine coolant on drive belts.
3. Remove air duct (inlet) and air cleaner case assembly. Refer to EM-17, "
Component".
1. Reservoir tank cap 2. Reservoir tank 3. Reservoir tank hose
4. Clamp (reservoir tank hose) 5. Clamp (radiator hose) 6. Radiator hose (upper)
7. Radiator upper mount bracket 8. Mounting rubber (upper) 9. Radiator cap
10. Radiator 11. Mounting rubber (lower) 12. O-ring
13. Drain plug 14. Radiator hose (lower) 15. Clamp (A/T fluid cooler hose)
16. A/T fluid cooler hose 17. Radiator cooling fan assembly 18. Reservoir tank bracket
A. To water outlet B. To A/T fluid cooler tube C. To water inlet
JPBIA0989GB
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ENGINE COOLANTCO-37
< SERVICE INFORMATION > [VK45DE]
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ENGINE COOLANT
InspectionINFOID:0000000001325869
LEVEL CHECK
 Check if the reservoir tank engine coolant level is within the “MIN”
to “MAX” when engine is cool.
 Adjust the engine coolant level as necessary.
LEAK CHECK
 To check for leaks, apply pressure to the cooling system with radi-
ator cap tester (commercial serv ice tool) and radiator cap tester
adapter (commercial service tool) (A).
WARNING:
Do not remove radiator cap when engine is hot. Serious burns
could occur from high-pressure engine coolant escaping from
thermostat housing.
CAUTION:
Higher testing pressure than specified may cause radiator
damage.
NOTE:
In a case engine coolant decreases, r eplenish radiator with engine coolant.
 If anything is found, repair or replace damaged parts.
Changing Engine CoolantINFOID:0000000001325870
WARNING:
 To avoid being scalded, do not change engine coolant when 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 coolant in the system , open water drain plugs on cylinder block. Refer
to EM-242, "
Disassembly and Assembly".
3. Remove reservoir tank as necessary, and drain engine coolant and clean reservoir tank before installing.
SMA412B
Testing pressure : 157 kPa (1.6 kg/cm2, 23 psi)
JPBIA0828ZZ
SBIA0444E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C