ATC-2 Discharge Air Flow ................................................. 31
System Description ................................................. 32
SWITCHES AND THEIR CONTROL FUNCTION ... 32
CAN Communication System Description .............. 33
TROUBLE DIAGNOSIS ............................................ 34
CONSULT-II Function (BCM) .................................. 34
CONSULT-II BASIC OPERATION ....................... 34
DATA MONITOR .................................................. 34
How to Perform Trouble Diagnosis for Quick and
Accurate Repair ...................................................... 35
WORK FLOW ...................................................... 35
SYMPTOM TABLE .............................................. 35
Component Parts and Harness Connector Location ... 36
ENGINE COMPARTMENT .................................. 36
PASSENGER COMPARTMENT .......................... 37
Schematic ............................................................... 38
Wiring Diagram — A/C — ....................................... 39
Auto Amp. Terminals and Reference Value ............ 44
PIN CONNECTOR TERMINAL LAYOUT ............ 44
TERMINALS AND REFERENCE VALUE FOR
UNIFIED METER AND A/C AMP. ........................ 44
Self-diagnosis Function .......................................... 46
DESCRIPTION .................................................... 46
FUNCTION CONFIRMATION PROCEDURE ...... 47
AUXILIARY MECHANISM: TEMPERATURE
SETTING TRIMMER ........................................... 52
AUXILIARY MECHANISM: FOOT POSITION
SETTING TRIMMER ........................................... 53
AUXILIARY MECHANISM: INLET PORT MEM-
ORY FUNCTION ................................................. 53
Operational Check .................................................. 54
CHECKING MEMORY FUNCTION ..................... 54
CHECKING BLOWER ......................................... 54
CHECKING DISCHARGE AIR ............................ 54
CHECKING INTAKE AIR ..................................... 54
CHECKING TEMPERATURE DECREASE ......... 54
CHECKING TEMPERATURE INCREASE .......... 55
CHECKING A/C SWITCH ................................... 55
CHECKING AUTO MODE ................................... 55
Power Supply and Ground Circuit for Auto Amp. ... 56
INSPECTION FLOW ........................................... 56
COMPONENT DESCRIPTION ............................ 57
DIAGNOSIS PROCEDURE FOR A/C SYSTEM ... 57
LAN System Circuit ................................................ 59
DIAGNOSIS PROCEDURE FOR LAN CIRCUIT ... 59
Mode Door Motor Circuit ........................................ 63
INSPECTION FLOW ........................................... 63
SYSTEM DESCRIPTION .................................... 64
COMPONENT DESCRIPTION ............................ 65
DIAGNOSIS PROCEDURE FOR MODE DOOR
MOTOR ............................................................... 65
Air Mix Door Motor Circuit ...................................... 66
INSPECTION FLOW ........................................... 66
SYSTEM DESCRIPTION .................................... 67
COMPONENT DESCRIPTION ............................ 68
DIAGNOSIS PROCEDURE FOR AIR MIX DOOR
MOTOR ............................................................... 68
Air Mix Door Motor PBR Circuit .............................. 68DIAGNOSIS PROCEDURE FOR AIR MIX DOOR
MOTOR PBR ....................................................... 68
Intake Door Motor Circuit ........................................ 69
INSPECTION FLOW ............................................ 69
SYSTEM DESCRIPTION ..................................... 70
COMPONENT DESCRIPTION ............................ 71
DIAGNOSIS PROCEDURE FOR INTAKE DOOR
MOTOR ................................................................ 71
Blower Motor Circuit ................................................ 72
INSPECTION FLOW ............................................ 72
SYSTEM DESCRIPTION ..................................... 73
COMPONENT DESCRIPTION ............................ 74
DIAGNOSIS PROCEDURE FOR BLOWER
MOTOR ................................................................ 74
COMPONENT INSPECTION ............................... 77
Magnet Clutch Circuit .............................................. 78
INSPECTION FLOW ............................................ 78
SYSTEM DESCRIPTION ..................................... 79
DIAGNOSIS PROCEDURE FOR MAGNET
CLUTCH .............................................................. 79
COMPONENT INSPECTION ............................... 83
Insufficient Cooling .................................................. 84
INSPECTION FLOW ............................................ 84
PERFORMANCE TEST DIAGNOSIS .................. 85
PERFORMANCE CHART .................................... 87
TROUBLE DIAGNOSIS FOR UNUSUAL PRES-
SURE ................................................................... 88
Insufficient Heating ................................................. 91
INSPECTION FLOW ............................................ 91
Noise ....................................................................... 92
INSPECTION FLOW ............................................ 92
Self-diagnosis ......................................................... 94
INSPECTION FLOW ............................................ 94
Memory Function .................................................... 95
INSPECTION FLOW ............................................ 95
Ambient Sensor Circuit ........................................... 96
COMPONENT DESCRIPTION ............................ 96
AMBIENT TEMPERATURE INPUT PROCESS ... 96
DIAGNOSIS PROCEDURE FOR AMBIENT
SENSOR .............................................................. 96
COMPONENT INSPECTION ............................... 98
In-vehicle Sensor Circuit ......................................... 99
COMPONENT DESCRIPTION ............................ 99
DIAGNOSIS PROCEDURE FOR IN-VEHICLE
SENSOR ............................................................100
COMPONENT INSPECTION .............................101
Sunload Sensor Circuit .........................................102
COMPONENT DESCRIPTION ..........................102
SUNLOAD INPUT PROCESS ...........................102
DIAGNOSIS PROCEDURE FOR SUNLOAD
SENSOR ............................................................102
COMPONENT INSPECTION .............................104
Intake Sensor Circuit .............................................105
COMPONENT DESCRIPTION ..........................105
DIAGNOSIS PROCEDURE FOR INTAKE SEN-
SOR ...................................................................105
COMPONENT INSPECTION .............................106
REFRIGERATION SYSTEM
ATC-19
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REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleBJS000FF
REFRIGERANT FLOW
The refrigerant flows form 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 amp. will make the A/C relay go OFF and stop the compressor.
Refrigerant System ProtectionBJS000FG
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 (27.46 bar, 28 kg/cm
2 , 398 psi), or below
about 134 kPa (1.34 bar, 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 (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.
RJIA1745E
ATC-46
TROUBLE DIAGNOSIS
Self-diagnosis FunctionBJS000FX
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 A/C switch for at least 5 seconds. The A/C
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 to the next step is
accomplished by means of pressing temperature control switch (driver side), as required.
Additionally sifting from STEP-5 to AUXILIARY MECHANISM is accomplished by means of pressing (fan)
control switch (UP).
SJIA1670E
TROUBLE DIAGNOSIS
ATC-47
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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 A/C switch for at least 5 seconds.
CAUTION:
Press A/C switch after indicating LED of intake switch.
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 control switch (UP, 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 switch (DOWN, 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 AT C - 9 4 , "
Self-diagno-
sis" .
5. STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED
Press temperature control switch (UP, driver side).
Does code No. 30 appear on the display?
YES >> GO TO 6.
NO >> GO TO 14.
RHA970DB
RHA869DD
TROUBLE DIAGNOSIS
ATC-49
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8. STEP-5: TEMPERATURE OF EACH SENSOR IS CHECKED
1. Press temperature control switch (UP, 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 AT C - 9 6 , "
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 AT C - 9 9 , "
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 ATC-105, "
Intake
Sensor Circuit" .
RJIA3240E
RJIA3241E
RJIA3242E
TROUBLE DIAGNOSIS
ATC-57
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COMPONENT DESCRIPTION
Unified Meter and A/C amp. (Automatic Amplifier)
The unified meter and A/C amp. has a built-in microcomputer which
processes information sent from various sensors needed for air con-
ditioner operation. The air mix door motor, mode door motor, intake
door motor, blower motor and compressor are then controlled.
When the various switches and temperature contorol switch are
operated, data is input to the unified meter and A/C amp. from the
display unit / display control unit using CAN communication.
Self-diagnosis functions are also built into unified meter and A/C
amp. to provide quick check of malfunctions in the auto air condi-
tioner system.
Potentio Temperature Control (PTC)
The PTC is built into the A/C and AV switch. It can be set at an inter-
val of 0.5°C in the 18°C to 32°C temperature range by turning tem-
perature control switch. The set temperature is displayed.
DIAGNOSIS PROCEDURE FOR A/C SYSTEM
SYMPTOM: A/C system does not come on.
RJIA2732E
RJIA3253E
SJIA0301E
ATC-66
TROUBLE DIAGNOSIS
Air Mix Door Motor CircuitBJS000G2
SYMPTOM
Discharge air temperature does not change.
Air mix door motor does not operate normally.
INSPECTION FLOW
*1ATC-47, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2 to 6.*2ATC-96, "
Ambient Sensor Circuit"*3ATC-99, "In-vehicle Sensor Circuit"
*4ATC-102, "Sunload Sensor Circuit"*5ATC-66, "Air Mix Door Motor Circuit"*6ATC-47, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.
*7ATC-59, "
LAN System Circuit"*8ATC-124, "AIR MIX DOOR MOTOR"*9ATC-54, "Operational Check"
*10ATC-35, "SYMPTOM TABLE"*11ATC-105, "Intake Sensor Circuit"
RJIA3256E
ATC-70
TROUBLE DIAGNOSIS
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
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
SJIA1651E
RJIA4067E