Cold Air Intake System INFINITI FX35 2008 Service Manual

ATC-18
< SERVICE INFORMATION >
REFRIGERATION SYSTEM
Evaporator intake air temperature is less than 20°C (68 °F).
Engine is running at speeds less than 1,500 rpm.
This is because the V-6 compressor prov ides a means of “capacity” control.
2. The V-6 variable compressor provides refrigerant c ontrol under varying conditions. During cold winters, it
may not produce high refrigerant pressure discharge (compared to previous units) when used with air
conditioning systems.
3. A “clanking” sound may occasionally be heard during re frigerant charge. The sound indicates that the tilt
angle of the wobble (swash) plate has changed and is not a malfunction.
4. For air conditioning systems with the V-6 compresso r, the clutch remains engaged unless: the system
main switch, fan switch or ignition switch is tur ned OFF. When ambient (outside) temperatures are low or
when the amount of refrigerant is insufficient, t he clutch is disengaged to protect the compressor.
DESCRIPTION
General
The variable compressor is a swash plate type that c hanges piston stroke in response to the required cooling
capacity.
The tilt of the wobble (swash) plate allows the piston’ s stroke to change so that refrigerant discharge continu-
ously change from 14.5 to 184 cm
3 (0.885 to 11.228 cu in).
RJIA1260E
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ATC-24
< SERVICE INFORMATION >
AIR CONDITIONER CONTROL
AIR CONDITIONER CONTROL
Description of Air Conditioner LAN Control SystemINFOID:0000000001328167
The LAN (Local Area Network) syst em consists of unified meter and A/C amp., mode door motor, air mix door
motors and intake door motor.
A configuration of these component s is shown in the figure below.
System ConstructionINFOID:0000000001328168
A small network is constructed between the unifi ed meter and A/C amp., air mix door motors, mode door
motor and intake door motor. The unified meter and A/C amp. and motors are connected by data transmission
lines and motor power supply lines. The LAN network is built through the ground circuits of each door motor.
Addresses, motor opening angle signals, motor stop si gnals and error checking messages are all transmitted
through the data transmission lines connecting the unified meter and A/C amp. and each door motor.
The following functions are contained in LCUs built into the air mix door motors, the mode door motor and the
intake door motor.
 Address
 Motor opening angle signals
 Data transmission
 Motor stop and drive decision
 Opening angle sensor (PBR function)
 Comparison
 Decision (Unified meter and A/C amp. indicated value and motor opening angle comparison)
OPERATION
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends mode door, air mix door and intake door opening angle data to the mode door motor LCU, air mix door
motor LCU and intake door motor LCU.
The mode door motor, air mix door motors and intake door motor read their respective signals according to the
address signal. Opening angle indication signals received from the unified meter and A/C amp. and each of
the motor position sensors is 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 is returned to the unified meter and A/C amp.
SJIA1609E
RJIA1747E
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ATC-58
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
SYSTEM DESCRIPTION
Component Parts
Mode door control system components are:
 Unified meter and A/C amp.
 Mode door motor (LCU)
 A/C LAN system (PBR built-in mode door motor, air mix door motor and intake door motor)
 In-vehicle sensor
 Ambient sensor
 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 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 received 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.
Mode Door Control Specification
*1 ATC-29, "Discharge Air Flow"*2AT C - 5 0 , "Operational Check"*3ATC-43, "Self-Diagnosis Function",
see No. 4 to 6.
*4 ATC-86, "
Ambient Sensor Circuit"*5AT C - 8 8 , "In-vehicle Sensor Circuit"*6ATC-91, "Sunload Sensor Circuit"
*7 ATC-94, "Intake Sensor Circuit"*8AT C - 5 9 , "Air Mix Door Motor Circuit"*9ATC-43, "Self-Diagnosis Function",
see No. 13.
*10 ATC-54, "
LAN System Circuit"*11AT C - 11 3*12ATC-32, "How to Perform Trouble Di-
agnosis for Quick and Accurate Re-
pair"
SJIA1585E
RJIA1778E
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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
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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-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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ATC-80
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too low.  There is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.
 Liquid tank inlet and expan-
sion valve are frosted. Liquid tank inside is slightly
clogged.
 Replace liquid tank.
 Check lubricant for contami-
nation.
 Temperature of expansion valve inlet is extremely low
as compared with areas
near liquid tank.
 Expansion valve inlet is frosted.
 Temperature difference oc- curs somewhere in high-
pressure side. High-pressure pipe located be-
tween liquid tank and expan-
sion valve is clogged.
 Check and repair malfunc-
tioning parts.
 Check lubricant for contami- nation.
Expansion valve and liquid
tank are warm or slightly cool
when touched. Low refrigerant charge.
↓
Leaking fittings or compo-
nents.
Check refrigerant for leaks.
Refer to
ATC-138, "
Checking
of Refrigerant Leaks".
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted. Expansion valve closes a little
compared with the specifica-
tion.
↓
1. Improper expansion
valve adjustment.
2. Malfunctioning expansion
valve.
3. Outlet and inlet may be clogged.  Remove foreign particles by
using compressed air.
 Replace expansion valve.
 Check lubricant for contami-
nation.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet. Low-pressure pipe is clogged
or crushed.  Check and repair malfunc-
tioning parts.
 Check lubricant for contami- nation.
Air flow volume is not enough
or is too low. Evaporator is frozen.  Check intake sensor circuit.
Refer to AT C - 9 4 , "
Intake
Sensor Circuit".
 Replace compressor.
 Repair evaporator fins.
 Replace evaporator.
Refer to AT C - 6 4 , "
Blower
Motor Circuit".
AC353A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes be-
comes negative.  Air conditioning system does
not function and does not cy-
clically cool the compart-
ment air.
 The system constantly func- tions for a certain period of
time after compressor is
stopped and restarted. Refrigerant does not discharge
cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refrigerant.
 Drain water from refrigerant
or replace refrigerant.
 Replace liquid tank.
AC354A
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REFRIGERANT LINESATC-141
< SERVICE INFORMATION >
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6. Do not stop when one leak is found. Continue to check for additional leaks at all system components.
If no leaks are found, perform steps 7 - 10.
7. Start the engine.
8. Set the A/C control as follows;
a. A/C switch: ON
b. Mode door position: VENT (Ventilation)
c. Intake position: Recirculation
d. Temperature setting: Max. cold
e. Fan speed: High
9. Run engine at 1,500 rpm for at least 2 minutes.
10. Stop the engine and perform leak check again following steps 4 through 6 above.
Refrigerant leaks should be chec ked immediately after stopping
the engine. Begin with the leak detector at the compressor. The
pressure on the high-pressure side will gradually drop after
refrigerant circulation stops and pressure on the low-pressure
side will gradually rise, as shown in the graph. Some leaks are
more easily detected when pressure is high.
11. Before connecting recovery/recycling recharging equipm ent to vehicle, check recovery/recycling recharg-
ing equipment gauges. No refrigerant pressure should be displayed. If pressure is displayed, recover
refrigerant from equipment lines and then check refrigerant purity.
12. Confirm refrigerant purity in supply tank using recovery/recycling recharging equipment and refrigerant
identifier.
13. Confirm refrigerant purity in vehicle A/C system us ing recovery/recycling recharging equipment and refrig-
erant identifier.
14. Discharge A/C system using approved refrigerant recove ry equipment. Repair the leaking fitting or com-
ponent if necessary.
15. Evacuate and recharge A/C system and perform the l eak test to confirm no refrigerant leaks.
16. Perform A/C performance test to ensure system works properly.
SHA839E
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EC-94
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS

If DTC U1000 or U1001 is displayed with other DT C, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-146
.
 If DTC U1010 is displayed with other DTC, fi rst perform the trouble diagnosis for DTC U1010.
Refer to EC-148
.
*: Models with ICC.Priority Detected items (DTC)
1  U1000 U1001 CAN communication line  U1010 CAN communication
 P0101 P0102 P0103 Mass air flow sensor
 P0112 P0113 P0127 Intake air temperature sensor
 P0117 P0118 P0125 Engine coolant temperature sensor
 P0128 Thermostat function
 P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor
 P0181 P0182 P0183 Fuel tank temperature sensor
 P0327 P0328 Knock sensor
 P0335 Crankshaft position sensor (POS)
 P0340 P0345 Camshaft position sensor (PHASE)
 P0460 P0461 P0462 P0463 Fuel level sensor
 P0500 Vehicle speed sensor
 P0605 ECM
 P0643 Sensor power supply
 P0700 TCM
 P0705 Park/neutral position (PNP) switch
 P0850 Park/neutral position (PNP) switch
 P1610 - P1615 NATS
 P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
2  P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater  P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater
 P0075 P0081 Intake valve timing control solenoid valve
 P0130 P0131 P0132 P0133 P0150 P0151 P0152 P0153 P2A00 P2A03 Air fuel ratio (A/F) sensor 1
 P0137 P0138 P0139 P0157 P0158 P0159 Heated oxygen sensor 2
 P0441 EVAP control system purge flow monitoring
 P0443 P0444 P0445 EVAP canister purge volume control solenoid valve
 P0447 P0448 EVAP canister vent control valve
 P0451 P0452 P0453 EVAP control system pressure sensor
 P0550 Power steering pressure sensor
 P0603 ECM power supply
 P0710 P0717 P0720 P0731 P0732 P0733 P0734 P0735 P0740 P0744 P0745 P1730 P1752 P1757 P1762 P1767
P1772 P1774 A/T related sensors, solenoid valves and switches
 P1217 Engine over temperature (OVERHEAT)
 P1805 Brake switch
 P2100 P2103 P2118 Electric throttle control actuator
 P2101 Electric throttle control function
3  P0011 P0021 Intake valve timing control  P0171 P0172 P0174 P0175 Fuel injection system function
 P0300 - P0306 Misfire
 P0420 P0430 Three way catalyst function
 P0442 EVAP control system (SMALL LEAK)
 P0455 EVAP control system (GROSS LEAK)
 P0456 EVAP control sys tem (VERY SMALL LEAK)
 P0506 P0507 Idle speed control system
 P1148 P1168 Closed loop control
 P1211 TCS control unit
 P1212 TCS communication line
 P1421 COLD START CONTROL
 P1564 ICC steering switch/ASCD steering switch
 P1568 ICC command valve*
 P1572 ICC brake switch/ASCD brake switch
 P1574 ICC vehicle speed sensor/ASCD vehicle speed sensor
 P1715 Turbine revolution sensor
 P2119 Electric throttle control actuator
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DTC P1421 COLD START CONTROLEC-451
< SERVICE INFORMATION > [VQ35DE]
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DTC P1421 COLD START CONTROL
DescriptionINFOID:0000000001326309
ECM controls ignition timing and engine idle speed when engine is started with prewarming up condition.
This control promotes the activation of three way ca
talyst by heating the catalyst and reduces emissions.
On Board Diagnosis LogicINFOID:0000000001326310
DTC Confirmation ProcedureINFOID:0000000001326311
NOTE:
 If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
 If DTC P1421 is displayed with other DTC, firs t perform the trouble diagnosis for other DTC.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Check that the “COOLAN TEMP/S” indication is between 4°C (39 °F) and 36 °C (97 °F).
If “COOLAN TEMP/S” indication is within the specified value, go to the following step.
If “COOLANT TEMP/S” indication is out of the specified value, cool engine down or warm engine up and
go to step 1.
5. Start engine and let it idle for 5 minutes.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-451, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001326312
1.PERFORM IDLE AIR VOLUME LEARNING
Perform EC-85, "
Idle Air Volume Learning".
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 2.
No >> Follow the instruction of Idle Air Volume Learning.
2.CHECK INTAKE SYSTEM
Check for the cause of intake air volume lacking. Refer to the following.
 Crushed intake air passage
 Intake air passage clogging
OK or NG
OK >> GO TO 3.
NG >> Repair or replace malfunctioning part
3.CHECK FUEL INJECTION SYSTEM FUNCTION
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1421
1421 Cold start emission reduction
strategy monitoring ECM does not control ignition timing and engine
idle speed properly when engine is started with
prewarming up condition.  Lack of intake air volume
 Fuel injection system
ECM
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