service INFINITI FX35 2008 Service Manual

TROUBLE DIAGNOSISATC-63
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SYSTEM DESCRIPTION
Component Parts
Intake door control system components are: Unified meter and A/C amp.
 Intake 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
*1 AT C - 5 0 , "Operational Check"*2AT C - 4 3 , "Self-Diagnosis Function",
see No. 4 to 6. *3
AT C - 8 6 , "Ambient Sensor Circuit"
*4 AT C - 8 8 , "In-vehicle Sensor Circuit"*5AT C - 9 1 , "Sunload Sensor Circuit"*6 AT C - 9 4 , "Intake Sensor Circuit"
*7 AT C - 5 9 , "Air Mix Door Motor Circuit"*8AT C - 3 2 , "How to Perform Trouble
Diagnosis for Quick and Accurate
Repair"
*9 AT C - 4 3 , "Self-Diagnosis Function",
see No. 13.
*10 AT C - 5 4 , "
LAN System Circuit"*11AT C - 1 0 6
SJIA1807E
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-64
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
 Intake sensor
System Operation
The intake door control determines intake door position based on the ambient temperature, the intake air tem-
perature and the in-vehicle temperature. When the DEF, or OFF switches are pressed or A/C switch is OFF,
the unified meter and A/C amp. sets the intake door at the FRE position.
Intake Door Control Specification
COMPONENT DESCRIPTION
Intake Door Motor
The intake door motor is attached to the blower unit. It rotates so that
air is drawn from inlets set by the unified meter and A/C amp. Motor
rotation is conveyed to a lever which activates the intake door.
DIAGNOSIS PROCEDURE FOR INTAKE DOOR MOTOR
SYMPTOM: Intake door motor does not operate normally.
Perform diagnosis procedure. Refer to ATC-54, "
LAN System Circuit".
Blower Motor CircuitINFOID:0000000001328189
SYMPTOM: Blower motor operation is malfunctioning.
INSPECTION FLOW
SJIA1588E
RJIA1787E
RJIA0897E
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISATC-65
< SERVICE INFORMATION >
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SYSTEM DESCRIPTION
Component Parts
Fan speed control system components are:
 Unified meter and A/C amp.
 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
*1 AT C - 5 0 , "Operational Check"*2AT C - 4 3 , "Self-Diagnosis Function",
see No. 4. *3
AT C - 4 3 , "Self-Diagnosis Function",
see No. 6.
*4 AT C - 8 6 , "
Ambient Sensor Circuit"*5AT C - 8 8 , "In-vehicle Sensor Circuit"*6 AT C - 9 1 , "Sunload Sensor Circuit"
*7AT C - 9 4 , "Intake Sensor Circuit"*8AT C - 3 2 , "How to Perform Trouble Di-
agnosis for Quick and Accurate Re-
pair"
*9 AT C - 4 3 , "Self-Diagnosis Function",
see No. 13.
*10 "DIAGNOSIS PROCEDURE FOR BLOWER MOTOR" *11
EC-193
(VQ35DE) or EC-779
(VK45DE)
SJIA1808E
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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
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TROUBLE DIAGNOSISATC-67
< SERVICE INFORMATION >
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COMPONENT DESCRIPTION
Brush-Less Motor
The blower motor utilizes a brush-less motor with a rotating magnet.
Quietness is improved over previous motors where the brush was
the point of contact and the coil rotated.
DIAGNOSIS PROCEDURE FOR BLOWER MOTOR
SYMPTOM: Blower motor operation is malfunctioning.
1.CHECK POWER SUPPLY FOR BLOWER MOTOR
1. Disconnect blower motor connector.
2. Turn ignition switch ON.
3. Check voltage between blower motor harness connector M78 terminal 1 and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 15A fuses [Nos. 10 and 11, located in the fuse block (J/B)]. Refer to PG-
77.
 If fuses are OK, check harness for open circuit. Repair or replace if necessary.
 If fuses are NG, check harness fo r short circuit and replace fuse.
2.CHECK BLOWER MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between blower motor harness connector M78 terminal 3 and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3.CHECK CIRCUIT CONTINUITY BETWEEN BLOWER MOTOR AND UNIFIED METER AND A/C AMP.
1. Disconnect unified meter and A/C amp. connector.
ZHA152H
SJIA0266E
1 – Ground : Battery voltage
RJIA1997E
3 – Ground : Continuity should exist.
RJIA1998E
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-68
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
2. Check continuity between blower motor harness connector M78terminal 2 and unified meter and A/C amp. harness connector
M57 terminal 53.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4.CHECK UNIFIED METER AND A/C AMP. OUTPUT SIGNAL
1. Reconnect blower motor connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Change the fan speed from Lo to Hi, and check the duty ratios between blower motor harness connector M78 terminal 2 and
ground using an oscilloscope. Normal terminal 2 drive signal
duty ratios are shown in the table below.
OK or NG
OK >> Replace blower motor after conf irming the fan air flow does not change.
NG >> Replace unified meter and A/C amp.
COMPONENT INSPECTION
Blower Motor
2 – 53 : Continuity should exist.
RJIA1999E
RJIA2000E
SJIA1802E
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TROUBLE DIAGNOSISATC-69
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Confirm smooth rotation of the blower motor.
 Ensure that there are no foreign particles inside the blower unit.
Magnet Clutch CircuitINFOID:0000000001328190
SYMPTOM: Magnet clutch does not engage.
INSPECTION FLOW
RJIA0905E
*1 AT C - 9 4 , "Intake Sensor Circuit"*2AT C - 8 6 , "Ambient Sensor Circuit"*3 AT C - 4 3 , "Self-Diagnosis Function",
see No. 13.
SJIA1590E
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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-71
< SERVICE INFORMATION >
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OK or NG
OK >> GO TO 2.
NG >>  Malfunctioning ambient sensor: Refer to ATC-86, "
Ambient Sensor Circuit".
 Malfunctioning intake sensor: Refer to ATC-94, "
Intake Sensor Circuit".
2.PERFORM IPDM E/R AUTO ACTIVE TEST
Perform “IPDM E/R auto active test”. Refer to PG-20, "
Auto Active Test".
Does the magnet clutch operate?
YES >>  WITH CONSULT-III: GO TO 5  WITHOUT CONSULT-III: GO TO 6.
NO >> Check 10A fuse (No. 79, located in IPDM E/R). Refer to PG-23, "
IPDM E/R Terminal Arrange-
ment", and GO TO 3.
3.CHECK CIRCUIT CONTINUITY BETWEEN IPDM E/R AND COMPRESSOR
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector and compressor connector.
3. Check continuity between IPDM E/R harness connector E8 ter- minal 33 and compressor harness connector F2 terminal 1.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4.CHECK MAGNET CLUTCH CIRCUIT
Check for operation sound when applying battery voltage direct cur-
rent to terminal.
OK or NG
OK >> 1. Replace IPDM E/R. 2. Go to self-diagnosis procedure ATC-43, "
Self-Diag-
nosis Function" and perform self-diagnosis STEP-4.
Confirm that magnet clutch operation normal.
NG >> 1. Replace magnet clutch.
2. Go to self-diagnosis procedure ATC-43, "
Self-Diag-
nosis Function" and perform self-diagnosis STEP-4.
Confirm that magnet clutch operation normal.
5.CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal in “Data monitor”. Refer to ATC-32, "
CONSULT-III Function".
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6.CHECK CIRCUIT CONTINUITY BETWEEN BC M AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect BCM connector and unified meter and A/C amp. connector.
33 – 1 : Continui ty should exist.
RJIA2004E
RJIA2005E
A/C SW ON : AIR COND SW ON
A/C SW OFF : AIR COND SW OFF
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

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
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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