ATC-1
AUTOMATIC AIR CONDITIONER
J AIR CONDITIONER
CONTENTS
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AUTOMATIC AIR CONDITIONER
PRECAUTIONS .......................................................... 4
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 4
Precautions for Working with HFC-134a (R-134a) ..... 4
General Refrigerant Precautions .............................. 5
Lubricant Precautions .............................................. 5
Precautions for Refrigerant Connection ................... 5
FEATURES OF NEW TYPE REFRIGERANT
CONNECTION ...................................................... 6
O-RING AND REFRIGERANT CONNECTION ..... 7
Precautions for Servicing Compressor ................... 10
Precautions for Service Equipment ........................ 10
RECOVERY/RECYCLING EQUIPMENT ............ 10
ELECTRONIC LEAK DETECTOR ...................... 10
VACUUM PUMP ................................................. 10
MANIFOLD GAUGE SET .................................... 10
SERVICE HOSES ................................................ 11
SERVICE COUPLERS ......................................... 11
REFRIGERANT WEIGHT SCALE ....................... 11
CALIBRATING ACR4 WEIGHT SCALE ............... 11
CHARGING CYLINDER ...................................... 12
Precautions for Leak Detection Dye ....................... 12
IDENTIFICATION ................................................ 13
IDENTIFICATION LABEL FOR VEHICLE ........... 13
Wiring Diagrams and Trouble Diagnosis ................ 13
PREPARATION ......................................................... 14
Special Service Tools ............................................. 14
WITH GASOLINE ENGINE (CWV-615M COM-
PRESSOR) ......................................................... 14
WITH DIESEL ENGINE (DKV-11G COMPRES-
SOR) ................................................................... 14
HFC-134a (R-134a) Service Tools and Equipment ... 15
REFRIGERATION SYSTEM ..................................... 18
Refrigerant Cycle ................................................... 18
REFRIGERANT FLOW ....................................... 18
FREEZE PROTECTION (WITH GASOLINE
ENGINE: CWV-615M COMPRESSOR) .............. 18
Refrigerant System Protection ............................... 18
REFRIGERANT PRESSURE SENSOR (WITH GASOLINE ENGINE: CWV-615M COMPRES-
SOR) ................................................................... 18
DUAL-PRESSURE SWITCH (WITH DIESEL
ENGINE: DKV-11G COMPRESSOR) .................. 18
PRESSURE RELIEF VALVE (WITH GASOLINE
ENGINE: CWV-615M COMPRESSOR) .............. 18
V-6 Variable Displacement Compressor (With Gas-
oline Engine: CWV-615M Compressor) .................. 19
GENERAL INFORMATION ................................. 19
DESCRIPTION .................................................... 20
Component Layout ................................................. 23
LUBRICANT .............................................................. 24
Maintenance of Lubricant Quantity in Compressor ... 24
LUBRICANT ........................................................ 24
LUBRICANT RETURN OPERATION .................. 24
LUBRICANT ADJUSTING PROCEDURE FOR
COMPONENTS REPLACEMENT EXCEPT
COMPRESSOR .................................................. 25
LUBRICANT ADJUSTING PROCEDURE FOR
COMPRESSOR REPLACEMENT ....................... 25
AIR CONDITIONER CONTROL ............................... 27
Description of Air Conditioner LAN Control System ... 27
System Construction .............................................. 27
OPERATION ........................................................ 27
TRANSMISSION DATA AND TRANSMISSION
ORDER ............................................................... 28
AIR MIX DOOR CONTROL (AUTOMATIC TEM-
PERATURE CONTROL) ..................................... 29
FAN SPEED CONTROL ...................................... 29
INTAKE DOOR CONTROL ................................. 29
OUTLET DOOR CONTROL ................................ 29
MAGNET CLUTCH CONTROL ........................... 29
SELF-DIAGNOSTIC SYSTEM ............................ 29
Description of Control System ................................ 30
Control Operation ................................................... 31
MODE CONTROL DIAL ...................................... 31
TEMPERATURE CONTROL DIAL (POTENTIO
TEMPERATURE CONTROL) .............................. 31
FAN CONTROL DIAL .......................................... 31
REAR WINDOW DEFOGGER SWITCH ............. 31
ATC-2 INTAKE SWITCH ................................................. 31
A/C SWITCH ....................................................... 31
Discharge Air Flow ................................................. 32
System Description ................................................. 33
SWITCHES AND THEIR CONTROL FUNCTION ... 33
TROUBLE DIAGNOSIS ............................................ 34
How to Perform Trouble Diagnoses for Quick and
Accurate Repair ...................................................... 34
WORK FLOW ...................................................... 34
SYMPTOM TABLE .............................................. 34
Component Parts and Harness Connector Location ... 35
ENGINE COMPARTMENT .................................. 35
PASSENGER COMPARTMENT .......................... 36
Schematic ............................................................... 37
WITH GASOLINE ENGINE ................................. 37
WITH DIESEL ENGINE ....................................... 38
Wiring Diagram —A/C— ......................................... 39
WITH GASOLINE ENGINE / LHD MODELS ....... 39
WITH GASOLINE ENGINE / RHD MODELS ...... 43
WITH DIESEL ENGINE / LHD MODELS ............ 47
WITH DIESEL ENGINE / RHD MODELS ............ 51
Auto Amp. Terminals and Reference Value ............ 55
PIN CONNECTOR TERMINAL LAYOUT ............ 55
TERMINALS AND REFERENCE VALUE FOR
AUTO AMP. ......................................................... 55
Self-diagnosis Function .......................................... 57
DESCRIPTION .................................................... 57
FUNCTION CONFIRMATION PROCEDURE ...... 59
AUXILIARY MECHANISM: TEMPERATURE
SETTING TRIMMER ........................................... 63
AUXILIARY MECHANISM: FOOT POSITION
SETTING TRIMMER ........................................... 63
AUXILIARY MECHANISM: INLET PORT MEM-
ORY FUNCTION ................................................. 64
Operational Check .................................................. 65
CHECKING BLOWER ......................................... 65
CHECKING DISCHARGE AIR ............................ 65
CHECKING INTAKE DOOR ................................ 65
CHECKING TEMPERATURE DECREASE ......... 66
CHECKING TEMPERATURE INCREASE .......... 66
CHECKING A/C SWITCH ................................... 66
Power Supply and Ground Circuit for Auto Amp. ... 67
INSPECTION FLOW ........................................... 67
COMPONENT DESCRIPTION ............................ 67
DIAGNOSTIC PROCEDURE FOR A/C SYSTEM ... 68
LAN System Circuit ................................................ 69
DIAGNOSTIC PROCEDURE FOR LAN CIR-
CUIT .................................................................... 69
Mode Door Motor Circuit ........................................ 73
INSPECTION FLOW ........................................... 73
SYSTEM DESCRIPTION .................................... 74
COMPONENT DESCRIPTION ............................ 75
DIAGNOSTIC PROCEDURE FOR MODE
DOOR MOTOR ................................................... 75
Air Mix Door Motor Circuit ...................................... 76
INSPECTION FLOW ........................................... 76
SYSTEM DESCRIPTION .................................... 77
COMPONENT DESCRIPTION ............................ 78
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR .................................................... 78
Intake Door Motor Circuit ........................................ 79
INSPECTION FLOW ............................................ 79
SYSTEM DESCRIPTION ..................................... 80
COMPONENT DESCRIPTION ............................ 81
DIAGNOSTIC PROCEDURE FOR INTAKE
DOOR MOTOR .................................................... 81
Blower Motor Circuit ................................................ 82
INSPECTION FLOW ............................................ 82
SYSTEM DESCRIPTION ..................................... 83
COMPONENT DESCRIPTION ............................ 84
DIAGNOSTIC PROCEDURE FOR BLOWER
MOTOR ................................................................ 84
COMPONENT INSPECTION ............................... 87
Magnet Clutch Circuit .............................................. 88
INSPECTION FLOW ............................................ 88
SYSTEM DESCRIPTION ..................................... 89
DIAGNOSTIC PROCEDURE FOR MAGNET
CLUTCH .............................................................. 89
COMPONENT INSPECTION ............................... 94
Insufficient Cooling .................................................. 96
INSPECTION FLOW ............................................ 96
PERFORMANCE TEST DIAGNOSIS .................. 98
PERFORMANCE CHART ..................................100
TROUBLE DIAGNOSIS FOR UNUSUAL PRES-
SURE .................................................................102
Insufficient Heating ...............................................105
INSPECTION FLOW ..........................................105
Noise .....................................................................107
INSPECTION FLOW ..........................................107
Self-Diagnosis .......................................................108
INSPECTION FLOW ..........................................108
Ambient Sensor Circuit .........................................109
COMPONENT DESCRIPTION ..........................109
AMBIENT TEMPERATURE INPUT PROCESS .109
DIAGNOSTIC PROCEDURE FOR AMBIENT
SENSOR ............................................................109
COMPONENT INSPECTION ............................. 111
In-Vehicle Sensor Circuit ....................................... 111
COMPONENT DESCRIPTION .......................... 111
DIAGNOSTIC PROCEDURE FOR IN-VEHICLE
SENSOR ............................................................112
COMPONENT INSPECTION .............................113
Sunload Sensor Circuit .........................................114
COMPONENT DESCRIPTION ..........................114
SUNLOAD INPUT PROCESS ...........................114
DIAGNOSTIC PROCEDURE FOR SUNLOAD
SENSOR ............................................................114
COMPONENT INSPECTION .............................116
Intake Sensor Circuit .............................................117
COMPONENT DESCRIPTION ..........................117
DIAGNOSTIC PROCEDURE FOR INTAKE SEN-
SOR ...................................................................117
COMPONENT INSPECTION .............................119
CONTROLLER ........................................................120
Removal and Installation .......................................120
REMOVAL ..........................................................120
INSTALLATION ..................................................120
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AMBIENT SENSOR ................................................ 121
Removal and Installation ...................................... 121
REMOVAL ......................................................... 121
INSTALLATION ................................................. 121
IN-VEHICLE SENSOR ............................................ 122
Removal and Installation ...................................... 122
REMOVAL ......................................................... 122
INSTALLATION ................................................. 122
SUNLOAD SENSOR .............................................. 123
Removal and Installation ...................................... 123
REMOVAL ......................................................... 123
INSTALLATION ................................................. 123
INTAKE SENSOR ................................................... 124
Removal and Installation ...................................... 124
REMOVAL ......................................................... 124
INSTALLATION ................................................. 124
BLOWER UNIT ....................................................... 125
Removal and Installation ...................................... 125
REMOVAL ......................................................... 125
INSTALLATION ................................................. 125
Disassembly and Assembly ................................. 126
BLOWER MOTOR .................................................. 127
Removal and Installation ...................................... 127
REMOVAL ......................................................... 127
INSTALLATION ................................................. 127
INTAKE DOOR MOTOR ......................................... 128
Removal and Installation ...................................... 128
REMOVAL ......................................................... 128
INSTALLATION ................................................. 128
FAN CONTROL AMPLIFIER .................................. 129
Removal and Installation ...................................... 129
REMOVAL ......................................................... 129
INSTALLATION ................................................. 129
AIR CONDITIONER FILTER ................................... 130
Removal and Installation ...................................... 130
FUNCTION ........................................................ 130
REPLACEMENT TIMING .................................. 130
REPLACEMENT PROCEDURES ..................... 130
HEATER & COOLING UNIT ASSEMBLY .............. 131
Removal and Installation ...................................... 131
REMOVAL ......................................................... 131
INSTALLATION ................................................. 132
Disassembly and Assembly ................................. 132
MODE DOOR MOTOR ........................................... 134
Removal and Installation ...................................... 134
REMOVAL ......................................................... 134
INSTALLATION ................................................. 134
AIR MIX DOOR MOTOR ......................................... 135
Removal and Installation ...................................... 135
REMOVAL ......................................................... 135
INSTALLATION ................................................. 135
HEATER CORE ...................................................... 136
Removal and Installation ...................................... 136
REMOVAL ......................................................... 136
INSTALLATION ................................................. 136
DUCTS AND GRILLES .......................................... 137
Removal and Installation ...................................... 137
REMOVAL ......................................................... 137
INSTALLATION ................................................. 140REFRIGERANT LINES ...........................................141
HFC-134a (R-134a) Service Procedure ...............141
SETTING OF SERVICE TOOLS AND EQUIP-
MENT ................................................................141
Components .........................................................143
WITH GASOLINE ENGINE ...............................143
WITH DIESEL ENGINE .....................................144
Removal and Installation of Compressor ..............144
REMOVAL .........................................................144
INSTALLATION .................................................146
Removal and Installation of Compressor Clutch ..146
REMOVAL .........................................................146
INSTALLATION .................................................150
Removal and Installation of Low-pressure Flexible
Hose .....................................................................153
REMOVAL .........................................................153
INSTALLATION .................................................154
Removal and Installation of High-pressure Flexible
Hose .....................................................................154
REMOVAL .........................................................154
INSTALLATION .................................................155
Removal and Installation of High-pressure Pipe ..155
REMOVAL .........................................................155
INSTALLATION .................................................155
Removal and Installation of Condenser ................155
REMOVAL .........................................................155
INSTALLATION .................................................156
Removal and Installation of Liquid Tank ...............156
REMOVAL .........................................................156
INSTALLATION .................................................157
Removal and Installation of Refrigerant Pressure
Sensor ..................................................................157
REMOVAL .........................................................157
INSTALLATION .................................................157
Removal and Installation of Dual-pressure Switch .158
REMOVAL .........................................................158
INSTALLATION .................................................158
Removal and Installation of Evaporator ................158
REMOVAL .........................................................158
INSTALLATION .................................................159
Removal and Installation of Expansion Valve .......159
REMOVAL .........................................................159
INSTALLATION .................................................159
Checking for Refrigerant Leaks ............................160
Checking System for Leaks Using the Fluorescent
Leak Detector .......................................................160
Dye Injection .........................................................160
Electronic Refrigerant Leak Detector ....................161
PRECAUTIONS FOR HANDLING LEAK
DETECTOR .......................................................161
CHECKING PROCEDURE ...............................161
SERVICE DATA AND SPECIFICATIONS (SDS) ....164
Compressor ..........................................................164
Lubricant ...............................................................164
Refrigerant ............................................................164
Engine Idling Speed .............................................164
Belt Tension ..........................................................164
PRECAUTIONS
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General Refrigerant PrecautionsEJS000T2
WARNING:
Do not release refrigerant into the air. Use approved recovery/recycling equipment to capture the
refrigerant every time an air conditioning system is discharged.
Always wear eye and hand protection (goggles and gloves) when working with any refrigerant or
air conditioning system.
Do not store or heat refrigerant containers above 52°C (125°F).
Do not heat a refrigerant container with an open flame; if container warming is required, place the
bottom of the container in a warm pail of water.
Do not intentionally drop, puncture, or incinerate refrigerant containers.
Keep refrigerant away from open flames: poisonous gas will be produced if refrigerant burns.
Refrigerant will displace oxygen, therefore be certain to work in well ventilated areas to prevent
suffocation.
Do not pressure test or leak test HFC-134a (R-134a) service equipment and/or vehicle air condi-
tioning systems with compressed air during repair. Some mixtures of air and HFC-134a (R-134a)
have been shown to be combustible at elevated pressures. These mixtures, if ignited, may cause
injury or property damage. Additional health and safety information may be obtained from refriger-
ant manufacturers.
Lubricant PrecautionsEJS0027Y
Use only specified lubricant for the HFC-134a (R-134a) A/C system and HFC-134a (R-134a) components.
If lubricant other than that specified is used, compressor malfunction is likely to occur.
The specified HFC-134a (R-134a) lubricant rapidly absorbs moisture from the atmosphere. The following
handling precautions must be observed:
When removing refrigerant components from a vehicle, immediately cap (seal) the component to minimize
the entry of moisture from the atmosphere.
When installing refrigerant components to a vehicle, do not remove the caps (unseal) until just before con-
necting the components. Connect all refrigerant loop components as quickly as possible to minimize the
entry of moisture into system.
Only use the specified lubricant from a sealed container. Immediately reseal containers of lubricant. With-
out proper sealing, lubricant will become moisture saturated and should not be used.
Avoid breathing A/C refrigerant and lubricant vapor or mist. Exposure may irritate eyes, nose and throat.
Use only approved recovery/recycling equipment to discharge HFC-134a (R-134a) refrigerant. If acciden-
tal system discharge occurs, ventilate work area before resuming service. Additional health and safety
information may be obtained from refrigerant and lubricant manufacturers.
Do not allow lubricant (Nissan A/C System Oil Type S or R) to come in contact with styrofoam parts. Dam-
age may result.
Precautions for Refrigerant ConnectionEJS000T4
A new type refrigerant connection has been introduced to all refrigerant lines except the following location.
Expansion valve to cooling unit
Refrigerant pressure sensor to liquid tank
ATC-18
REFRIGERATION SYSTEM
REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleEJS000TD
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 coil is
controlled by an externally equalized expansion valve, located inside the evaporator case.
FREEZE PROTECTION (WITH GASOLINE ENGINE: CWV-615M COMPRESSOR)
Under usual operating conditions, when the A/C is switched on, the compressor runs continuously, and the
evaporator pressure, and therefore, temperature is controlled by the V-6 variable displacement compressor to
prevent freeze up.
Refrigerant System ProtectionEJS000TE
REFRIGERANT PRESSURE SENSOR (WITH GASOLINE ENGINE: CWV-615M COMPRESSOR)
The refrigerant system is protected against excessively high- or low-pressures by the refrigerant pressure sen-
sor, located on the liquid tank. If the system pressure rises above, or falls below the specifications, the refriger-
ant 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 (27.46 bar, 28 kg/cm
2 , 398 psi), or below
about 134 kPa (1.34 bar, 1.4 kg/cm
2 , 20 psi).
DUAL-PRESSURE SWITCH (WITH DIESEL ENGINE: DKV-11G COMPRESSOR)
The refrigerant system is protected against excessively high- or low-pressures by the dual-pressure switch,
located on the liquid tank. If the system pressure rises above or falls below the specifications, the dual-pres-
sure switch opens to interrupt the compressor operation.
PRESSURE RELIEF VALVE (WITH GASOLINE ENGINE: CWV-615M COMPRESSOR)
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 (37.27 bar,
38 kg/cm
2 , 540 psi)], the release port on the pressure relief valve automatically opens and releases refriger-
ant into the atmosphere.
RJIA0676E
AIR CONDITIONER CONTROL
ATC-27
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AIR CONDITIONER CONTROLPFP:27500
Description of Air Conditioner LAN Control SystemEJS000TI
The LAN (Local Area Network) system consists of auto amp., mode door motor, air mix door motor and intake
door motor.
A configuration of these components is shown in the diagram below.
System ConstructionEJS000TJ
A small network is constructed between the auto amp., air mix door motor, mode door motor and intake door
motor. The auto 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 auto amp. and each door motor.
The following functions are contained in LCUs built into air mix door motor, mode door motor and intake door
motor.
Address
Motor opening angle signal
Data transmission
Motor stop and drive decision
Opening angle sensor (PBR function)
Comparison
Decision (Auto amp. indicated value and motor opening angle comparison)
OPERATION
The auto amp. receives data from each of the sensors. The auto 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 auto 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, DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection data is
returned to the auto amp.
RJIA0480E
RHA350H
AIR CONDITIONER CONTROL
ATC-29
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Stop Signal:
At the end of each transmission, a stop operation, in-operation, or internal malfunction message is delivered to
the auto amp. This completes one data transmission and control cycle.
AIR MIX DOOR CONTROL (AUTOMATIC TEMPERATURE CONTROL)
The air mix door is automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by the temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.
FAN SPEED CONTROL
Blower speed is automatically controlled by the temperature setting, ambient temperature, in-vehicle tempera-
ture, intake temperature, amount of sunload and air mix door position.
With FAN control dial set to AUTO, the blower motor starts to gradually increase air flow volume.
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake doors are automatically controlled by the temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and ON-OFF operation of the compressor.
OUTLET DOOR CONTROL
The outlet door is automatically controlled by the temperature setting, ambient temperature, in-vehicle temper-
ature, intake temperature and amount of sunload.
MAGNET CLUTCH CONTROL
The ECM controls compressor operation using input signals from the throttle position sensor, refrigerant pres-
sure sensor (or dual-pressure switch) and auto amp.
SELF-DIAGNOSTIC SYSTEM
The self-diagnostic system is built into the auto amp. to quickly locate the cause of symptoms.
RHA352H
ATC-30
AIR CONDITIONER CONTROL
Description of Control SystemEJS000TK
The control system consists of input sensors, switches, the auto amp. (microcomputer) and outputs.
The relationship of these components is shown in the diagram below:
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