sensor INFINITI FX35 2005 Service Manual

ATC-12
PRECAUTIONS
Revision: 2005 July 2005 FX
CAUTION:
The new and former refrigerant connections use different O-ring configurations. Never confuse O-
rings since they are not interchangeable. If a wrong O-ring is installed, refrigerant will leak at, or
around, the connection.
O-Ring Part Numbers and Specifications
WARNING:
Make sure all refrigerant is discharged into the recycling equipment and the pressure in the system is
less than atmospheric pressure. Then gradually loosen the discharge side hose fitting and remove it.
CAUTION:
When replacing or cleaning refrigerant cycle components, observe the following.

When the compressor is removed, store it in the same way as it is when mounted on the car. Fail-
ure to do so will cause lubricant to enter the low-pressure chamber.

When connecting tubes, always use a torque wrench and a back-up wrench.

After disconnecting tubes, immediately plug all openings to prevent entry of dirt and moisture.

When installing an air conditioner in the vehicle, connect the pipes at the final stage of the opera-
tion. Never remove the seal caps of pipes and other components until just before required for con-
nection.

Allow components stored in cool areas to warm to working area temperature before removing seal
caps. This prevents condensation from forming inside A/C components.

Thoroughly remove moisture from the refrigeration system before charging the refrigerant.

Always replace used O-rings.

When connecting tube, apply lubricant to circle of the O-rings shown in illustration. Be careful not
to apply lubricant to threaded portion.

O-ring must be closely attached to dented portion of tube.

When replacing the O-ring, be careful not to damage O-ring and tube.

Connect tube until a click can be heard, then tighten the nut or bolt by hand until snug. Make sure
that the O-ring is installed to tube correctly.
Connection type Piping connection point Part number QTY O-ring size
New Low-pressure pipe 1 to low-pressure pipe 2 (One-touch joint) 92473 N8221 2 16
Low-pressure pipe 2 to expansion valve 92473 N8210 1 16
High-pressure pipe 1 to high-pressure pipe 2 (One-touch joint) 92471 N8221 2 8
High-pressure pipe 3 to expansion valve 92471 N8210 1 8
High-pressure pipe 2 to high-pressure pipe 3 (One-touch joint) 92471 N8221 2 8
Condenser to high-pressure flexible hose (One-touch joint) 92472 N8221 2 12
Condenser to high-pressure pipe 1 (One-touch joint) 92471 N8221 2 8
Low-pressure flexible hose to low-pressure pipe 1 (One-touch joint) 92473 N8221 2 16
Compressor to low-pressure flexible hose 92474 N8210 1 19
Compressor to high-pressure flexible hose 92472 N8210 1 12
Liquid tank to condenser pipe Inlet
92471 N8210 1
8
Outlet 1
Former Refrigerant pressure sensor to condenser J2476 89956 1 10
Expansion valve to evaporator Inlet 92475 71L00 1 12
Outlet 92475 72L00 1 16
Lubricant name : Nissan A/C System Oil Type S
Part number : KLH00-PAGS0

REFRIGERATION SYSTEM ATC-21
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REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleAJS00146
REFRIGERANT FLOW
The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank,
through the evaporator, and back to the compressor. The refrigerant evaporation through 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 ProtectionAJS00147
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: 2005 July 2005 FX
AIR CONDITIONER CONTROLPFP:27500
Description of Air Conditioner LAN Control SystemAJS0014A
The LAN (Local Area Network) system consists of unified meter and A/C amp., mode door motor, air mix door
motor and intake door motor.
A configuration of these components is shown in the diagram below.
System ConstructionAJS0014B
A small network is constructed between the unified meter and A/C amp., air mix door motor, 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 motor, 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 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 is compared by the LCUs in each motor with the existing decision and opening
angles. Subsequently, HOT/COLD, DEF/VENT and FRESH/RECIRCULATION 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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MAGNET CLUTCH CONTROL
When A/C switch or DEF switch is pressed, unified meter and A/C amp. inputs compressor ON signal to BCM.
BCM sends compressor ON signal to ECM, via CAN communication line.
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 line.
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 line, ECM simultaneously sends
compressor feedback signal to unified meter and A/C amp. via CAN communication line.
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 symp-
toms.
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ATC-34
AIR CONDITIONER CONTROL
Revision: 2005 July 2005 FX
Description of Control SystemAJS0014C
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 OperationAJS0014D
DISPLAY SCREEN
Displays the operational status of the system.
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TROUBLE DIAGNOSIS ATC-51
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Auto Amp. Terminals and Reference ValueAJS0014O
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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Terminal No. Wire
color Item
Ignition
switch Condition
Voltage
(V)
1 L CAN-H — — —
11 R C A N - L — — —
21 R/W Power supply for BATT OFF — Battery voltage
22 G/R Power supply for IGN ON — Battery voltage
29 B Ground (Power) ON — Approx. 0
30 B Ground ON —- Approx. 0
35 LG/R Power supply for 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) Approx. 5
43 G/B A/C LAN signal ON —
HAK0652D

ATC-52
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
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 step
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) Approx. 5
Te r m i n a l
No. Wire
color ItemIgnition
switch Condition Voltag e
(V)
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TROUBLE DIAGNOSIS ATC-53
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Self-diagnosis FunctionAJS0014P
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 usual 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 to
another is accomplished by means of pressing temperature switch (driver side), as required.
Shifting from STEP-5 to AUXILIARY MECHANISM is accomplished by means of pressing (fan) UP switch.
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ATC-54
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
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.
CAUTION:

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 func-
tion.
>> 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 (UP) switch (driver side).
Advance to self
-diagnosis STEP-3?
YES >> GO TO 4.
NO >> Replace A/C and AV switch. (Temperature dial malfunctions.)
4. CHECK TO RETURN SELF-DIAGNOSIS STEP-2
Press temperature (DOWN) switch (driver side).
Return to self
-diagnosis STEP-2?
YES >> GO TO 5.
NO >> Malfunctioning OFF switch or unified meter and A/C amp. Refer to ATC-102, "
Self-diagnosis" .
5. STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED
Press temperature (UP) switch (driver side).
Does code No. 30 appear on the display?
YES >> GO TO 6.
NO >> GO TO 14.
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ATC-56
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
8. STEP-5: TEMPERATURE OF EACH SENSOR IS CHECKED
1. Press temperature (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 temperature shown on display greatly differs from actual tempera-
ture, check sensor circuit first, then inspect sensor.
OK or NG
OK >> GO TO 10.
NG >> Go to Ambient Sensor Circuit. Refer to ATC-104, "
Ambi-
ent Sensor Circuit" .
10. CHECK IN-VEHICLE SENSOR
Press (DEF) switch a second time. Temperature detected by in-
vehicle sensor is indicated on the display.
NOTE:
If temperature shown on display greatly differs from actual tempera-
ture, check sensor circuit first, then inspect sensor.
OK or NG
OK >> GO TO 11.
NG >> Go to In-vehicle Sensor Circuit. Refer to ATC-107, "
In-
vehicle Sensor Circuit" .
11 . CHECK INTAKE SENSOR
Press (DEF) switch a third time. Temperature detected by intake
sensor is indicated on the display.
NOTE:
If temperature shown on display greatly differs from actual tempera-
ture, check sensor circuit first, then inspect sensor.
OK or NG
OK >> GO TO 12.
NG >> Go to Intake Sensor Circuit. Refer to AT C - 11 3 , "
Intake
Sensor Circuit" .
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