2008 INFINITI FX35 engine

TROUBLE DIAGNOSISATC-43
< SERVICE INFORMATION >
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Self-Diagnosis FunctionINFOID:0000000001328181
DESCRIPTION
The self-diagnosis system diagnoses sensors, door motors, blower motor, etc. by system line. Refer to appli-
cable sections (items) for details. Shifting from norma l control to the self-diagnosis system is accomplished by
starting the engine (turning the ignition switch ON) and pr essing OFF switch for at least 5 seconds. The OFF
switch must be pressed within 10 seconds after starting the engine (ignition switch is turned ON). This system
will be canceled by either pressing AUTO switch or turn ing the ignition switch OFF. Shifting from one step is
accomplished by means of pressi ng temperature control switch (driver side), as required.
43 G/B A/C LAN signal ON —
45 PU/WECV (Electric Control Valve)
signal ONSelf-diagnosis. STEP-4
(Code No. 45)
46 L/W Power supply for IGN2 ON — Battery voltage
49 W/G Sensor ground ON — Approx. 0
50 LG Sunload sensor — — —
53 G Blower motor control signal ON Blower speed: 1st speed (man-
ual)
54 Y/R Power supply for each door
motor ON — Battery voltage
57 BR/Y Blower motor ON signal ON A/C switch: ON
(Blower motor operates.)
Approx. 0
OFF switch: ON
(A/C system: OFF)
Te r m i n a l
No. Wire
color ItemIgnition
switch Condition Vol tag e
(V)
SJIA1453J
SJIA1607E
SJIA1454J
SJIA1474J
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-44
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Shifting from STEP-5 to AUXILIARY MECHANISM is accomplished by means of pressing (fan) UP switch.
FUNCTION CONFIRMATION PROCEDURE
1.SET IN SELF-DIAGNOSIS MODE
1. Turn ignition switch ON.
2. Set in self-diagnosis mode as follows. Within 10 seconds after starting engine (ignition switch is turned ON.), press OFF switch for at least 5 seconds.
NOTE:
 If battery voltage drops below 12 V during diagnosis STEP-3, door motor speed becomes slower and as a
result, the system may generate an error even when operation is normal. To avoid this, start engine before
performing this diagnosis.
 Former STEP-1 (LEDs and display screen are checked) does not exist in this self-diagnosis function.
>> GO TO 2.
2.STEP-2: SENSOR CIRCUITS ARE CHECK ED FOR OPEN OR SHORT CIRCUIT
SJIA1571E
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ATC-50
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
4. Press the mode switch as desired.
When battery cable is disconnected or battery voltage is below 10 V, trimmer operation is canceled. Wind dis-
tribution ratio set becomes that of initial condition.
AUXILIARY MECHANISM: INLET PORT MEMORY FUNCTION
When ignition switch is turned from OFF to ON, inlet port memory function at manual mode can be set.
Operating procedures for this trimmer are as follows:1. Begin self-diagnosis STEP-5 mode. Refer to "Self-diagnosis Function".
2. Press (fan) UP switch to set system in auxiliary mode.
3. Press the intake switch as desired.
When battery cable is disconnected or battery voltage is below 10 V, memory function is canceled. Memory
function set becomes that of initial condition.
Operational CheckINFOID:0000000001328182
The purpose of the operational check is to c heck if the individual system operates properly.
CHECKING MEMORY FUNCTION
1. Press the temperature control (UP) switch (driver side) until 32°C (90 °F) is displayed.
2. Press OFF switch.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous temperature.
7. Press OFF switch.
If NG, go to trouble diagnosis procedure for ATC-85, "
Memory Function".
If OK, continue the check.
CHECKING BLOWER
SJIA1581E
LED status of
FRE position LED status of
REC position Setting status
Setting changeover
method
FRE REC
OFF OFF AUTO control AUTO control
Intake SW: ON
OFF ON AUTO control (Initial setting)
Manual REC status is memorized.
(Initial setting)
ON OFF Manual FRE status is memorized. AUTO control
ON ON Manual FRE status is memorized. Manual REC status is memorized.
Conditions : Engine running at normal operating temperature
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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
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ATC-72
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
3. Check continuity between BCM harness connector M3 terminal27 and unified meter and A/C amp. harness connector M57 ter-
minal 42.
OK or NG
OK >> GO TO 7.
NG >> Repair harness or connector.
7.CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (COMPRESSOR ON SIGNAL)
1. Reconnect BCM connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Check voltage between unified meter and A/C amp. harness connector M57 terminal 42 and ground using an oscilloscope.
OK or NG
OK >> GO TO 8.
NG-1 >> If the voltage is approx. 5 V when A/C switch is ON: Replace unified meter and A/C amp.
NG-2 >> If the voltage is approx. 0 V w hen A/C switch is OFF: Replace BCM.
8.CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-III
1. Start the engine.
2. Check voltage of refrigerant pressure sensor in “Data monitor”. Refer to EC-127, "
CONSULT-III Reference
Value in Data Monitor Mode" (VQ35DE) or EC-705, "CONSULT-III Reference Value in Data Monitor
Mode" (VK45DE).
WITHOUT CONSULT-III
1. Start the engine. 27 – 42 : Continuity should exist.
RJIA2006E
RJIA2007E
Te r m i n a l s
Condition Voltage
(+)
(− )
Unified meter
and A/C amp.
connector Te r m i n a l
No.
M57 42 Ground A/C switch: ON
(Blower motor operates.)
Approx. 0 V
OFF switch: ON
(A/C system: OFF)
SJIA1423J
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ATC-78
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Test Reading
Recirculating-to-discharge Air Temperature Table
Ambient Air Temperature-to -operating Pressure Table
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
Hood Open
TEMP. Max. COLD
Mode switch (Ventilation) set
Intake switch (Recirculation) set
Fan (blower) speed Max. speed set
Engine speed Idle speed
Operate the air conditioning system for 10 minutes before taking measurements.
Inside air (Recirculating air) at blower assembly inlet Discharge air temperature at center ventilator
°C ( °F)
Relative humidity
% Air temperature
°C ( °F)
50 - 60 20 (68) 11.2 - 13.2 (52 - 56)
25 (77) 12.2 - 14.8 (54 - 59)
30 (86) 15.5 - 18.6 (60 - 65)
35 (95) 21.0 - 24.5 (70 - 76)
40 (104) 28.7 - 32.6 (84 - 91)
60 - 70 20 (68) 13.2 - 15.2 (56 - 59)
25 (77) 14.8 - 17.3 (59 - 63)
30 (86) 18.6 - 21.6 (65 - 71)
35 (95) 24.5 - 28.0 (76 - 82)
40 (104) 32.6 - 36.5 (91 - 98)
Ambient air High-pressure (Discharge side)
kPa (kg/cm
2, psi) Low-pressure (Suction side)
kPa (kg/cm2, psi)
Relative humidity
% Air temperature
°C ( °F)
50 - 70 20 (68)
961 - 1,167
(9.8 - 11.9, 139 - 169) 216 - 265
(2.2 - 2.7, 31 - 38)
25 (77) 1,108 - 1,353
(11.3 - 13.8, 161 - 196) 230 - 281
(2.3 - 2.9, 33 - 41)
30 (86) 1,275 - 1,549
(13.0 - 15.8, 185 - 225) 261 - 320
(2.7 - 3.3, 38 - 46)
35 (95) 1,549 - 1,893
(15.8 - 19.3, 225 - 274) 297 - 364
(3.0 - 3.7, 43 - 53)
40 (104) 1,814 - 2,216
(18.5 - 22.6, 263 - 321) 357 - 435
(3.6 - 4.4, 52 - 63)
Vehicle condition Indoors or in the shade (in a well-ventilated place)
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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
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISATC-83
< SERVICE INFORMATION >
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NoiseINFOID:0000000001328193
SYMPTOM: Noise
INSPECTION FLOW
*1 AT C - 5 0 , "Operational Check"*2AT C - 5 9 , "Air Mix Door Motor Circuit"*3AT C - 4 3 , "Self-Diagnosis Function",
see No. 4 to 6.
*4 AT C - 4 3 , "
Self-Diagnosis Function",
see No. 13. *5
AT C - 5 4 , "LAN System Circuit"*6AT C - 6 4 , "Blower Motor Circuit"
*7 EC-193 (VQ35DE) or EC-779
(VK45DE) *8
CO-10, "Changing Engine Coolant"
(VQ35DE) or CO-37, "
Changing En-
gine Coolant" (VK45DE) *9
CO-14, "
Checking Radiator Cap"
(VQ35DE) or CO-42, "
Checking Ra-
diator Cap" (VK45DE)
SJIA1593E
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