Page 3425 of 4179

AIR CONDITIONER CONTROL
ATC-29
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AT C
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
Page 3426 of 4179
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:
RJIA3093E
Page 3427 of 4179

AIR CONDITIONER CONTROL
ATC-31
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Control OperationEJS004G9
MODE CONTROL DIAL
Controls the air discharge outlets.
Positions the air outlet doors to the defrost position. Also positions the intake doors to the outside air position.
When shifting mode control dial to DEF under the following conditions, compressor is turned ON. (A/C LED
ON)
FAN: O N
A/C: OFF
TEMPERATURE CONTROL DIAL (POTENTIO TEMPERATURE CONTROL)
Increase or decrease the set temperature.
FAN CONTROL DIAL
Automatically or Manually control the blower speed. Twenty-five speeds are available for manual control.
Shifting fan control dial to AUTO, compressor is turned ON automatically.
REAR WINDOW DEFOGGER SWITCH
When illumination is ON, rear window is defogged.
INTAKE SWITCH
When intake switch is ON, REC indicator turns ON, and air inlet is fixed to REC.
When press intake switch again, FRE indicator turns ON, and air inlet is fixed to FRE.
When intake switch is pressed for approximately 1.5 seconds or longer, REC and FRE indicators blink
twice. Then, automatic control mode is entered. Inlet status is displayed even during automatic control.
When DEF position or FRE indicator is turned ON, or when compressor is turned from ON to OFF, REC
switch is automatically turned OFF (fixed to FRE mode).
REC mode can be re-entered by pressing intake switch again. (Except DEF position)
A/C SWITCH
The compressor is ON or OFF.
(Pressing the A/C switch when the fan control dial is ON will turn off the A/C switch and compressor.)
SJIA0386E
Page 3428 of 4179
ATC-32
AIR CONDITIONER CONTROL
Discharge Air FlowEJS000TM
SJIA0441E
Page 3429 of 4179
AIR CONDITIONER CONTROL
ATC-33
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System DescriptionEJS000TN
SWITCHES AND THEIR CONTROL FUNCTION
RJIA2821E
RJIA2822E
Page 3430 of 4179

ATC-34
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSISPFP:00004
How to Perform Trouble Diagnoses for Quick and Accurate RepairEJS004GO
WORK FLOW
SYMPTOM TABLE
*1ATC-65, "Operational Check".
SHA900E
Symptom Reference Page
A/C system does not come on. Go to Trouble Diagnosis Procedure for A/C System.ATC-67, "
Power
Supply and
Ground Circuit for
Auto Amp."
Air outlet does not change.
Go to Trouble Diagnosis Procedure for Mode Door Motor. (LAN)ATC-73, "Mode
Door Motor Cir-
cuit"Mode door motor does not operate normally.
Discharge air temperature does not change.
Go to Trouble Diagnosis Procedure for Air Mix Door Motor. (LAN)AT C - 7 6 , "
Air Mix
Door Motor Cir-
cuit"Air mix door motor does not operate nor-
mally.
Intake door does not change.
Go to Trouble Diagnosis Procedure for Intake Door Motor. (LAN)AT C - 7 9 , "
Intake
Door Motor Cir-
cuit"Intake door motor does not operate normally.
Blower motor operation is malfunctioning.
Go to Trouble Diagnosis Procedure for Blower Motor.AT C - 8 2 , "
Blower
Motor Circuit"Blower motor operation is malfunctioning
under out of starting fan speed control.
Magnet clutch does not engage. Go to Trouble Diagnosis Procedure for Magnet Clutch.AT C - 8 8 , "
Magnet
Clutch Circuit"
Insufficient cooling Go to Trouble Diagnosis Procedure for Insufficient Cooling.ATC-96, "Insuffi-
cient Cooling"
Insufficient heating Go to Trouble Diagnosis Procedure for Insufficient Heating.ATC-105, "Insuffi-
cient Heating"
Noise Go to Trouble Diagnosis Procedure for Noise.ATC-107, "Noise"
Self-diagnosis cannot be performed. Go to Trouble Diagnosis Procedure for Self-diagnosis.ATC-108, "Self-
diagnosis"
Page 3431 of 4179
TROUBLE DIAGNOSIS
ATC-35
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AT C
Component Parts and Harness Connector LocationEJS004GP
ENGINE COMPARTMENT
RJIA0677E
Page 3432 of 4179
ATC-36
TROUBLE DIAGNOSIS
PASSENGER COMPARTMENT
RJIA2823E