sensor INFINITI FX35 2007 Service Manual

REFRIGERATION SYSTEM ATC-21
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Revision: 2006 July 2007 FX35/FX45
REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleNJS000DH
REFRIGERANT FLOW
The refrigerant flows from the compressor, through the condenser with liquid tank, through the evaporator, and
back to the compressor. The refrigerant evaporation in the evaporator is controlled by an externally equalized
expansion valve, located inside the evaporator case.
FREEZE PROTECTION
To prevent evaporator frozen up, the evaporator air temperature is monitored, and the voltage signal to the
unified meter and A/C auto amp. will make the A/C relay go OFF and stop the compressor.
Refrigerant System ProtectionNJS000DI
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively high- or low-pressure by the refrigerant pressure sen-
sor, located on the condenser. If the system pressure rises above, or falls below the specifications, the refrig-
erant pressure sensor detects the pressure inside the refrigerant line and sends the voltage signal to the ECM.
ECM makes the A/C relay go OFF and stops the compressor when pressure on the high-pressure side
detected by refrigerant pressure sensor is over about 2,746 kPa (28 kg/cm
2 , 398 psi), or below about 134 kPa
(1.4 kg/cm
2 , 20 psi).
PRESSURE RELIEF VALVE
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
When the pressure of refrigerant in the system increases to an unusual level [more than 3,727 kPa (38 kg/cm
2
, 540 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into the
atmosphere.
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ATC-30
AIR CONDITIONER CONTROL
Revision: 2006 July 2007 FX35/FX45
AIR CONDITIONER CONTROLPFP:27500
Description of Air Conditioner LAN Control SystemNJS000DM
The LAN (Local Area Network) system consists of unified meter and A/C amp., mode door motor, air mix door
motors and intake door motor.
A configuration of these components is shown in the figure below.
System ConstructionNJS000DN
A small network is constructed between the unified 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 signals 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.
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AIR CONDITIONER CONTROL ATC-33
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Revision: 2006 July 2007 FX35/FX45
MAGNET CLUTCH CONTROL
When A/C switch, AUTO switch or DEF switch is pressed, unified meter and A/C amp. transmits compressor
ON signal to BCM.
BCM sends compressor ON signal to ECM, via CAN communication.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant-pressure sen-
sor signal, throttle angle, etc.). If it judges compressor can be turned ON, it sends compressor ON signal to
IPDM E/R, via CAN communication.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.
When sending compressor ON signal to IPDM E/R via CAN communication, ECM simultaneously sends com-
pressor feedback signal to unified meter and A/C amp. via CAN communication.
Unified meter and A/C amp., then, uses input compressor feedback signal to control air inlet.
SELF-DIAGNOSIS SYSTEM
The self-diagnosis system is built into the unified meter and A/C amp. to quickly locate the cause of malfunc-
tions.
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ATC-34
AIR CONDITIONER CONTROL
Revision: 2006 July 2007 FX35/FX45
Description of Control SystemNJS000DO
The control system consists of input sensors, switches, the unified meter and A/C amp. (microcomputer) and
outputs. The relationship of these components is shown in the figure below:
Control OperationNJS000DP
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ATC-50
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Auto Amp. Terminals and Reference ValueNJS000DZ
Measure voltage between each terminal and ground by referring ter-
minals and reference value for unified meter and A/C amp.
PIN CONNECTOR TERMINAL LAYOUT
TERMINALS AND REFERENCE VALUE FOR UNIFIED METER AND A/C AMP.
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Te r m i n a l No. Wire
color Item
Ignition
switch Condition
Voltag e
(V)
1 L CAN-H — — —
11 P C A N - L — — —
21 R/W Power supply from BAT OFF — Battery voltage
22 W Power supply from IGN ON — Battery voltage
29 B Ground (Power) ON — Approx. 0
30 B Ground ON — Approx. 0
35 LG Power supply from ACC ACC — Battery voltage
39 Y Ambient sensor — — —
40 BR/W In-vehicle sensor — — —
41 P Intake sensor — — —
42 R/Y Compressor ON signal ON A/C switch: ON
(Blower motor operates.) Approx. 0
OFF switch: ON
(A/C system: OFF)
43 G/B A/C LAN signal ON —
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TROUBLE DIAGNOSIS ATC-51
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Revision: 2006 July 2007 FX35/FX45
45 PU/W ECV (Electric Control Valve)
signal ON
Self-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
(manual)
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)
Terminal
No. Wire
color ItemIgnition
switch Condition Voltage
(V)
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ATC-52
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Self-diagnosis FunctionNJS000E0
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 normal control to the self-diagnosis system is accomplished by
starting the engine (turning the ignition switch ON) and pressing 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 turning the ignition switch OFF. Shifting from one step is
accomplished by means of pressing temperature control switch (driver side), as required.
Shifting from STEP-5 to AUXILIARY MECHANISM is accomplished by means of pressing (fan) UP switch
(driver side).
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TROUBLE DIAGNOSIS ATC-53
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Revision: 2006 July 2007 FX35/FX45
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 CHECKED FOR OPEN OR SHORT CIRCUIT
Does code No. 20 appear on the display?
YES >> GO TO 3.
NO >> GO TO 13.
3. CHECK TO ADVANCE SELF-DIAGNOSIS STEP-3
Press temperature control (UP) switch (driver side).
Advance to self
-diagnosis STEP-3?
YES >> GO TO 4.
NO >> Replace A/C and AV switch. (Temperature control switch is malfunctioning.)
4. CHECK TO RETURN SELF-DIAGNOSIS STEP-2
Press temperature control (DOWN) switch (driver side).
Return to self
-diagnosis STEP-2?
YES >> GO TO 5.
NO >> Malfunctioning A/C and AV switch or unified meter and A/C amp. Refer to ATC-101, "
Self-diagno-
sis" .
5. STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED
Press temperature control (UP) switch (driver side).
Does code No. 30 appear on the display?
YES >> GO TO 6.
NO >> GO TO 14.
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TROUBLE DIAGNOSIS ATC-55
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Revision: 2006 July 2007 FX35/FX45
8. STEP-5: TEMPERATURE OF EACH SENSOR IS CHECKED
1. Press temperature control (UP) switch (driver side).
2. Code No. 51 appears on the display.
>> GO TO 9.
9. CHECK AMBIENT SENSOR
Press (DEF) switch one time. Temperature detected by ambient
sensor is indicated on the display.
NOTE:
If the temperature indicated on the display greatly differs from the
actual temperature, check sensor circuit first, and then check sensor.
OK or NG
OK >> GO TO 10.
NG >> Go to Ambient Sensor Circuit. Refer to ATC-103, "
Ambi-
ent Sensor Circuit" .
10. CHECK IN-VEHICLE SENSOR
Press (DEF) switch for the second time. Temperature detected
by in-vehicle sensor is indicated on the display.
NOTE:
If the temperature indicated on the display greatly differs from the
actual temperature, check sensor circuit first, and then check sensor.
OK or NG
OK >> GO TO 11.
NG >> Go to In-vehicle Sensor Circuit. Refer to ATC-106, "
In-
vehicle Sensor Circuit" .
11 . CHECK INTAKE SENSOR
Press (DEF) switch for the third time. Temperature detected by
intake sensor is indicated on the display.
NOTE:
If the temperature indicated on the display greatly differs from the
actual temperature, check sensor circuit first, and then check sensor.
OK or NG
OK >> GO TO 12.
NG >> Go to Intake Sensor Circuit. Refer to AT C - 11 2 , "
Intake
Sensor Circuit" .
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ATC-56
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
12. CHECK CAN COMMUNICATION ERROR
1. Press intake switch.
2. CAN communication error between the unified meter and A/C amp. and the display control unit can be detected as self-diag-
nosis results. (If plural errors occur, the display of each error will
blink twice for 0.5 second intervals.)
OK or NG
OK >> 1. Turn ignition switch OFF or AUTO switch ON. 2. INSPECTION END
NG >> Go to CAN communication. Refer to BCS-13, "
CAN
Communication Inspection Using CONSULT-II (Self-
Diagnosis)" .

Unified meter and A/C amp. - Display control unit
13. CHECK MALFUNCTIONING SENSOR AND DOOR MOTOR
Refer to the following chart for malfunctioning code No.
(If two or more sensors and door motors malfunction, corresponding code Nos. indicates 1 second each.)
*1: Perform self-diagnosis STEP-2 under sunshine.
When performing indoors, aim a light (more than 60 W) at sunload sensor, otherwise code No. 25 will indicate
despite that sunload sensor is functioning properly.
*2: ATC-103, "
DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR" .
*3: ATC-107, "
DIAGNOSIS PROCEDURE FOR IN-VEHICLE SENSOR" .
*4: AT C - 11 2 , "
DIAGNOSIS PROCEDURE FOR INTAKE SENSOR" .
*5: ATC-109, "
DIAGNOSIS PROCEDURE FOR SUNLOAD SENSOR" .
*6: AT C - 7 3 , "
DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR PBR" .
>> INSPECTION END
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Code No. Malfunctioning sensor and door motor (Including circuits) Reference page 21 / −21 Ambient sensor *2
22 / −22 In-vehicle sensor *3
24 / −24 Intake sensor *4
25 / −25
Sunload sensor
*1*5
26 / −26 Air mix door motor PBR (Driver side)
*6
27 / −27 Air mix door motor PBR (Passenger side)
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