CAUTION
When fasteners are removed, always
reinstall them at the same location from
which they were removed.  If a fastener
needs to be replaced, use the correct part
number fastener for that application.  If the
correct part number fastener is not available,
a fastener of equal size and strength (or
stronger) may be used. 
Fasteners that are not reused, and those
requiring thread locking compound, will be
called out.  The correct torque values must
be used when installing fasteners that
require it.  If the above conditions are not
followed, parts or system damage could
result.
SECTION 2C - HVAC AUTO AIR CONDITIONING
Full Automatic Air Conditioning System
General Description 
Full Automatic Air Conditioner Part Configuration
Circuit Diagram 
Function and Features
Full Automatic Air Conditioner Block Diagram
Air Conditioning Parts
Control Panel Layout
Air Control Functions 
Operation and Function of Control Panel Switches
Overview of Construction, Movement and Control of Major Parts of Full Automatic
Air Conditioner System
Overview of Automatic Control of Full Automatic Air Conditioner
Troubleshooting
Troubleshooting, Its Overview and Procedures 
Performance and Movement Checklist for Automatic Air Conditioner Related
Parts 
Troubleshooting with Self-Diagnosis Function
Inspection by Failed Location
Inspection of the Sensors
Inspection of the Intake Actuator System
Inspection of the Mix Actuator System
Inspection of the Mode Actuator System 
Inspection of the Fan Motor System
Inspection of the Magnet Clutch System
Inspection of the Air Conditioner Room Temperature Setup System 
Individual Inspection 
Sun Sensor..........................................................1B–128
Electronic Thermostat.................................................1B–128
Mode Actuator.......................................................1B–129
Mix Actuator.........................................................1B–129
Intake Actuator ......................................................1B–130
Techline

On-Vehicle Service

Power Transistor

Automatic Air Conditioner Control Unit

In Car Sensor

Ambient Sensor

Sun Sensor

Electronic Thermostat

Mode Actuator

Mix Actuator

Intake Actuator

FULL AUTOMATIC AIR CONDITIONING SYSTEM

GENERAL DESCRIPTION

Using a variety of sensors, this full automatic heater and air conditioner accurately senses outside air

temperature, solar radiation quantity, evaporator’s blowing temperature, heater core coolant temperature

and interior temperature, then enters these data to the automatic heater/air conditioner control unit

(equipped with the built-in micro-computer). The data provided to the control unit enables to automatically

control blow temperature and blow air quantity, turn on or off the compressor and switch the blow port as

well as switching between the fresh air intake and interior air circulation.

Resetting the automatic function allows you to switch to the manual control mode.

The self-diagnosis function of the automatic heater and air conditioner control unit (with the built-in micro-

computer) allows the unit to access and diagnose a failed part easier and quicker.

Full Automatic Air Conditioner Parts Configuration

865RY0004

Legend

(1) Lower Center Vent Box

(2) Sun Sensor

(3) Mix Actuator

(4) Mode Actuator

(5) Heater Unit

(6) In Car Sensor

(7) Pollen Filter

(8) Automatic Air Conditioner Control Unit

(9) Max-High Relay

(10) Blower Unit

(11) Intake Actuator

(12) Duct Sensor

(13) Evaporator Assembly

CIRCUIT DIAGRAM

6VE1

B-5

BLOWER

MOTOR

B-5

I-51

I-51I-51

MAX HI

RELAY

POWER

TRANSISTOR

I-50

H-20

H-26

H-20

2L/B

0.5P/G

I-32

P-2

0.85W/G

5W0.5R/W

0.3B

0.5R/W0.3R/W

TAIL RELAY(4)

ILLUMINATION

CONTROLLER 0.5G/R 0.85G/R

1.25B

1.25B 1.25B

0.5B

I-32

5W 3W

BATT

FL-1

80A

MAIN 4

B-36

3L/R C-19 25A

BLOWER C-20 10A

AIR CON

3L2L/B

0.3BR

0.5BR

0.3BR

2/B

0.3GR

0.3GR/L

0.5L/B

2/B

B-36

H-27

B-36H-14 1

B-36

HEATER & A/C RELAY

STARTER RELAY(1)

H-14

1H-13

I-32

H-26

C-16

10A CLOCK ROOM

BODY-RH

BODY-LH

B-18

B-19

B-1

AUTO A/C CONTROL UNIT AUTO A/C CONTROL UNIT

I-32

143521 12 33

I-32

296

I-33

H-20

H-16

I-33

I-50

D08RY00118

E-19

A/C TEHRMO

RELAY

THERMO

UNIT

PRESSURE

I-32

I-33

I-32

AUTO A/C CONTROL UNIT

H-16

H-241

H-611

H-16

H-416

0.5P/G

0.5Y/B 0.5Y/B

0.5P/G

0.5G/O

1.25B

0.5G/O

0.5G/B

0.5BR/Y0.5BR/Y 0.5BR/Y

0.3G/B

0.5L/O

0.5L/W

0.3L/R

0.3L/Y

0.3BR/B

0.5B1.25B

0.5G/B

0.5G/W0.5G/W 0.5G/W 0.5BR0.5LG0.5BR

0.5BR 0.5RB

0.5BR

0.3B/L

PCM(E15)

PCM(B14)

X - 5

X -5

H-16

H-24

X - 5

A/C COMPRESSOR

RELAY

MAGNETIC

CLUTCH

INTAKE

ACTUATOR

X - 7

X -7

X - 7

H-41

H-6

E-3

C-25

H-41

H-51

I-49

4612

MINCAR

SENSOR

I-34

I-49

I-49 I-49 I-49

I-34

I-33

101718193413317

H-41

D08RY00293

I-45

C-86

H-24

C-86 6

I-45

H-24

9 11 8 23 24 16 6 25 26 1 2 3 4

I-33

0.3LG/B 0.3LG/B 0.3B/L

0.3B/L

AMBIENT SENSOR

I-33 6

I-32

0.3V/W

0.3LG/W

0.3V/W

0.3B/L

0.3B/L 0.3B/L

0.3B/L

SUN SENSOR

MIX ACTUATOR

I-40

I-35

H-67

I-40 1

I-35

H-67

I-45

I-32

0.3V/R 0.3V/R

H-67

I-45 7

I-45

I-33

0.3V/G 0.3V/G 0.3B/L 0.3B/L

H-67

I-33

0.3V 0.3V

H-67

I-33

0.3LG/W

DUCT SENSOR

VENT B/L FOOT D/F DEF

B-69

H-26

B-69

I-32

0.3Y/BR0.3Y/BR

0.3Y/G

0.3GR/G

0.3GR

0.3GR/R

0.3Y/G

0.3GR

0.3GR/R

0.3GR/G0.3GR/G

0.3B/L 0.3B/L

0.3GR/L0.3GR/L

0.3GR/R

B-69

I-32

B-69 3

B-69

I-33

B-69

I-33

B-69

I-33

11 12 18 19 5 1

B-69 6

B-69

H-25 H-25 H-26 H-26 H-25 H-26

H-25

I-33 11

I-33

MODE ACTUATOR

AUTO A/C CONTROL UNIT

D08RY00120

4JX1

X-21

2 4

X-21

THERMO SW RELAY

0.5BR

0.5G/Y

QWS THERMO SW

0.5G/B

X-21

B-19

B-18

BODY-RH

I-32 I-33 I-32 I-32 I-33 I-33

I-32

10 7111213

1 2

B-36 B-36

H-26

5W 3W

3L/R

C-16

CLOCK, ROOM

BODY ENG. FRAME

10A

0.5Y/B 0.5Y/B 0.5Y/B

0.5R/G

0.5G/R 0.5G/R

ILLUMINATION

CONTROLLER

TAIL RELAY (4)

0.5R/W0.3R/W 0.5R/W0.5R/W

0.5BR 0.5BR

0.5BR

HEATER

& A/C RELAY

CHARGE

RELAY(1)

P-1

P-5

P-2

P-7P-10P-6

30B

8B/R

FL-1

80A MAIN

AUTO A/C CONTROL UNIT

I-32

H-27 1.25B

0.5B

1.25B

I-33

I-49

4612

I-49 I-49 I-49

I-49

0.5L/O

0.5L/W

0.3L/R

0.3L/Y

0.3B/L

1.25B 0.3B

0.5BR

C-25 C-25 21

H-26

0.5G/W

0.5LG

PRESSURE SW

INTAKE

ACTUATOR

H-14

H-13

10 0.85W/G0.85W/G

0.5B

0.5BR

H-16

H-4

0.5Y/B 0.5Y/B

H-17

H-24

0.5BR

3W/L

FL-3

40A C/HEAT

H-41 0.5G/Y ECM(J1-23)

H-2413

H-41

E-23

THERMO UNIT

I-32

2L/B2L/B

C-19 25A

BLOWER

MOTOR

C-20 10A

A/C

I-50

0.3GR/W

0.5L/B

0.3BR0.3BR

2L/B2B

I-33 33 22 34 19 18 1712

0.3GR/L

MAX HI RELAY

POWER

TRANSISTOR

I-513

H-26

I-51

I-50

I-51

I-50

I-51

B-5

H-20

I-33

143536721

H-20 1

B-1

D08RY00114

AUTO A/C CONTROL UNIT

0.3B/L

0.3G/W 0.3G/W

I-34

10 9 8 11 23 24 16 6 25 26 1 2 3 4 32 31 20 13

I-34

C-86

H-24

0.3LG/B

C-86

H-24

I-33

I-35

I-33

0.3BR/B

0.5B

0.3LG/B

I-352

0.3LG/W

0.3B/L

0.3LG/W

I-33

0.3B/L

I-32

I-45

H-674

I-45

H-67

I-33

H-676

I-32

H-675

I-33

H-677

I-45 I-45 I-45

0.3V/W

0.3V/R

0.3V/G

0.3V

0.3V/W

0.3V/R

0.3V/G

0.3V

B-69

H-25

H-26

0.3Y/BR

0.3Y/G

0.3GR

I-32 I-32 I-33

0.3Y/BR

0.3Y/G

0.3GR

B-69 B-69 B-69

B-69

VENT FOOT DEFB/L D/F

H-26

11 18

I-33I-33

X-12

2 4

X-12

X-5

2 4

1 3

X-5

X-5 X-5

0.5BR

H-41 0.5G/W

0.5G/O

0.5P/G

H-6H-41

H-17 E-27

0.5G/O

A/C THERMO

RELAY

0.5G/O

ECM(J1-31)

INCAR SENSOR

AMBIENT SENSOR

SUN SENSOR

DUCT SENSOR

MIX

ACTUATOR

MODE

ACTUATOR

I-33

B-69

27 6

B-69 B-69 B-69

I-32

MAGNETIC

CLUTCH

I-40

H-26

0.3GR/R

I-33

0.3GR/R

H-255

0.3GR/G

I-33

0.3GR/G

H-261

0.3GR/L

I-33

0.3GR/L

0.3GR/R

0.3B/L0.3B/L

0.3B/L

0.3G/B

0.3GR/G

0.5P/G

0.5P/G 16

H-16

CERAMIC

HEATER RELAY

CERAMIC

HEATER

DIODE

I-32

B-1

3W/L

0.5G/B 1B-44 2

B-44

0.5Y/G 0.5Y/G

H-15 0.3G/W

B-48

3W/G 15

H-13 3W/G 2B

BODY-LH

X-12

H-16

H-25

D08RY00115

FUNCTIONS AND FEATURES

• Automatic interior temperature control

This function enables to maintain the interior temperature at the level specified from the temperature

control switch despite of changes in factors such as vehicle speeds, outside air temperature and number

of passengers.

• Maximum cooling and heating function

You can select FC (Full cool, namely maximum cooling temperature) or FH (Full heat, maximum heating

temperature) from the temperature control lever.

• Automatic air flow control

Air flow is automatically and consecutively fine tuned according to the specified interior temperature and

changes in aperture of the heater unit mix door.

• Mode (blow port) control

This function automatically selects either one of the VENT, BI-LEVEL, FOOT or DEP mode for the blow

port according to changes of temperature on the blow port. Using the mode switch allows you to select a

desired blow port manually.

• Intake (switching between the fresh air intake and circulation of interior air) control

The intake (switching between fresh air intake and circulation of interior air) mode automatically selects

either FRESH (fresh air intake), MIX or RECIRC (interior air circulation) according to changes of the blow

port temperature. Using the intake switch allows you to select a desired intake port manually (in the

manual operation, FRESH and RECIRC modes alone are available). Pressing the DEF (defrost) mode

switch selects the FRESH (fresh air intake).

• Cooler start-up timing control

This function is used for maintaining the air flow at "LOW" level until the evaporator is sufficiently cooled

down. It is intended to prevent a large volume of hot air being blowing into inside of a vehicle when the

cooler is turned on in hot summer season.

• Heater start-up timing control

This function is used for maintained the air flow at "LOW" level and also for maintaining the defrost

mode until temperature of coolant in the heater core is sufficiently heated. It is intended to prevent a

large volume of cool air being blown into inside of a vehicle when the heater is turned on in cold winter

season.

• Solar radiation quantity offset control

The photodiode on the solar radiation sensor determines solar radiation quantity accurately to offset

interior temperature quickly.

• Switch position storing function

This function is used for storing switch positions being selected in the immediately preceding operation,

namely the last time the ignition has been turned off. It simplifies the setup procedures when restarting

the system.

• Self-diagnosis function

The self-diagnosis function turned on from the panel switch makes your troubleshooting easier (for detail

of this function, refer to the section titled "Self-Diagnosis").

FULL AUTO display

INTAKE indication

(LED)

(switching between

fresh and interior air)

MODE indication

(LED) (Blow port)

AC display (LED)

FAN indication (LED)

FAN KNOB

AUTO SET

REC FRESH SWITCH

TEMP LEVER

(temperature control)

MODE SWITCH

(blow port selection)

AC SWITCH

IN CAR SENSOR

AMBIENT SENSOR

SUN SENSOR

DUCT SENSOR

MIX ACTUATOR

POTENTIOMETER

MODE ACTUATOR

POTENTIOMETER

AIR MIX DOOR

MODE DOOR

INTAKE ACTUATOR

REC INTAKE DOOR

FAN MOTOR

POWER

TRANSISTOR

AUTOMATIC HEATER/AIR CONDITIONER CONTROL UNIT (with the built-in micro-computer)

MAX HI RELAY

PRESSURE

SWITCH AIR CONDITIONER

THERMO RELAY

COMPRESSOR

SWITCH

MAGNET

CLUTCH

PCM

PRESSURE

SWITCH AIR CONDITIONER

THERMO RELAY MAGNET

CLUTCH

(4JX1engine)

MIX FRESH

FULL AUTOMATIC AIR CONDITIONER BLOCK DIAGRAM

F01RY00009

12 13

852RY00001

Legend

(1) Liquid Line (High Pressure Pipe)

(2) Pressure Switch

(3) Ambient Sensor

(4) Receiver Drier

(5) Discharge Line (High Pressure Hose)

(6) Suction Line (Low Pressure Hose)

(7) Compressor

(8) Condenser Assembly

(9) Drive Belt

(10) Compressor Bracket

(11) Drain Hose

(12) Evaporator Assembly

(13) O-ring

AIR CONDITIONING PARTS

6VE1

852RY00003

Legend

(1) Liquid Line (High-Pressure Pipe)

(2) Pressure Switch

(3) Receiver Drier

(4) Ambient Sensor

(5) Compressor Bracket

(6) Discharge Line (High-Pressure Hose)

(7) Suction Line (Low-Pressure Hose)

(8) Compressor

(9) Condenser Assembly

(10) O-ring

(11) Insulator Pipe

(12) Suction Line (Low-Pressure Pipe)

(13) Drain Hose

(14) Evaporator Assembly

(15) A/C Switch

4JX1

865RY00026

678

345

MAX MAX

Legend

(1) Auto Switch

(2) Mode Switch

(3) DEF/FOOT Switch

(4) DEF Switch

(5) Intake Switch

(6) Fan Switch

(7) Air Conditioning Switch

(8) Temperature Control Knob

Control Panel Layout

C01RY00001

10 9

A B

A A B B

Vent Door

Mode Position Display of Intake Status Set Temperature

ON FULL

COLD FULL

HOT

20~30

B B A A

Blue

VENT BI-LEVEL FOOT DEF Red

OFF

Foot Door

DEF Door

Intake Door

Air Mix Door

Sub Air Mix Door

White

DEF/FOOT

Legend

(1) Interior Air Intake

(2) Fresh Air Intake

(3) Pollen Filter

(4) Evaporator Core

(5) Air Mix Door

(6) DEF Door

(7) Vent Door

(8) Foot Door

(9) Sub Air Mix Door

(10) Heater Unit

(11) Heater Core

(12) Evaporator Unit

(13) Blower Unit

Air Control Functions

OPERATION AND FUNCTIONS OF CONTROL PANEL SWITCHES

1. Auto Switch

(1) Pressing this switch turns on the automatic control mode. It resets all manual switches except that

for the fan control. However, when the Manual REC is selected for the intake or the Manual Open is

selected for the C/V, these modes are maintained.

(2) It causes the A/C (air conditioner) to the ON mode (this function, however, available only when the

fan is turned on and also the compressor is turned on because of the given outside air temperature

level).

• The AUTO LED comes on.

• Currently selected mode for the Mode and Intake are respectively indicated.

2. Mode Switch

(1) Pressing the VENT, B/L or FOOT switch selects the corresponding mode.

(2) When the Auto is selected for the Mode and Intake, pressing the mode switch fixes the Intake to the

immediately preceding status.

• Turns off the Auto LED.

• Currently selected blow port is indicated.

3. DEF Switch

Press this switch to select the DEF mode.

*1: When the manual REC is selected for the Intake, the manual REC is maintained.

*2: The ON mode is enabled only when the fun is turned on, and also the compressor is turned on

because of the given outside air temperature level.

• The Auto LED is turned off.

• DEF is indicated for the blow port, A/C LED comes on (only when the fan is turned on), and status

display is provided for the Intake.

Example 1:

4. Intake Switch

Pressing this switch sequentially selects a different intake port in the following order.

Example 1:

Example 2:

PUSH

Auto REC FRESH REC

PUSH PUSH

PUSH PUSH PUSH

Auto REC

MIX REC FRESH

DEF SW:ON

(Selects the DEF

mode)

A/C OFF

mode A/C ON

mode A/C ON mode is

maintained.

Mode switches for other than

the DEF mode: ON

(Resets the DEF mode)

Blow port Intake port A/C MIX

DEF Auto FRESH *1 ON mode *2 Auto

• The Auto LED maintains unaffected.

• Currently selected intake port is

indicated.

5. Fan Switch

(1) Sets the fan to the specified mode.

(2) Even when the fan switch is turned off, status display for the Model and Intake is maintained.

6. Temperature Control Knob

(1) This knob is operable only when the fan is turned on. It may be used for the MAX control of each

block except the fan.

(2) When the manual mode is selected for the fan control, this manual mode is maintained.

*1: In the A/C: OFF mode, FRESH shall be selected.

*2: The ON mode is available only when ON is selected for the fan as well as for the cold outside air

ON/OFF selection.

*3: When the MAX control is selected from the DEF mode, this DEF mode shall be maintained.

Example 1:

Example 2:

• As long as the MAX control is selected, the immediately preceding indication shall be maintained for

the AUTO.

• Status display is provided for others.

7. Air Conditioning Switch

Pressing this switch turns on or off the A/C (air conditioning) control. (The compressor remains turned

off if the fan is turned off and also the compressor has been turned off because of the given outside air

temperature level.)

(1) The A/C LED remains turned on even if the compressor has been turned off because of the given

outside air temperature level. In this case, however, the AUTO or DEF switch must be turned on and

the A/C ON mode must also be turned on (by the MAX/C mode).

(2) Pressing the A/C switch from the above state (1) turns off the A/C LED.

REC

MIX

FRE

Off

Selects MAX/COOL

(1): Mode

Manual B/L VENT Resets MAX/COOL Returns to (1) status.

Mode: Manual B/L

Selects MAX/COOL

(1): Mode

Manual B/L VENT Resets MAX/COOL Returns to (1) status.

Mode: Manual B/L

Mix Fan Mode Intake A/C

MAX/COOL Full cool MAX/HI VENT REC*1 ON mode*2

MAX/HEAT Full hot AUTO/HI FOOT*3 FRESH Current status

is maintained

OVERVIEW OF CONSTRUCTION,

MOVEMENT AND CONTROL OF MAJOR

PARTS OF FULL AUTOMATIC AIR

CONDITIONER SYSTEM

Automatic Heater/Air Conditioner Control Unit

Equipped with the built-in micro-computer, this

control unit operates on signals from sensors and

input signals from switches to offer total control of

the blower fan, and actuators used for the mode

door, intake door and air mix door.

Its self-diagnosis function enables quicker access to

a failed part and its more accurate troubleshooting.

In Car Sensor

It is a sensor used for detecting room temperature

of a vehicle. This sensor converts a given room

temperature into a resistance value before entering

the data to the automatic heater/air conditioner

control unit.

This in car sensor unites the power driven aspirator

and the motor fan so that a small amount of room

air may be constantly fed to the sensor.

This sensor is provided on the control panel.

Legend

(1) In Car Sensor

(2) Full Automatic Air Conditioner Control Unit

Ambient Sensor

This sensor is used for detecting temperature

outside the vehicle. It converts a given outside air

temperature into a resistance value before entering

the data to the automatic heater/air conditioner

control unit.

Thermal effects from the condenser and radiator

during idling after a run can be measured and offset

the automatic amplifier.

This sensor is provided on the side plate situated at

upper right side of the condenser.

Legend

(1) Ambient Sensor

(2) Condenser Assembly

•Duct Sensor

The sensor is the sensor to detect temperature

change of the side of evaporator blower coming

by fresh recirculation of intake door or "on" "off"

of compressor.

The temperature is converted to resistant rate.

And it works as thermostat to control to prevent

freezing of evaporator.

This sensor is installed in the upper case of

evaporator.

865RY00006

845RY00001

Legend

(1) Duct Sensor

(2) Evaporator Assembly

(3) Amplifierblock

In Car Sensor

It is a photodiode used for detecting quantity of

solar radiation. This sensor converts the offset

signal generated by changes in the interior

temperature (which results from fluctuations in

solar radiation) into photoelectric current to enter

into the automatic heater/air conditioner control

unit.

This sensor is provided at top of the defroster grill.

Legend

(1) Sun Sensor

Actuator

The actuators are power driven type containing a

small motor. Receiving output current from the

automatic heater/air conditioner control unit,

actuators drive the heater and blower unit mode

doors.

Actuators consist of the mode actuator used for

switching the mode (blow port selection), the mix

actuator used for changing aperture of the air mix

door, the intake actuator used for switching the

intake mode(fresh air/interior air).

Legend

(1) Mix Actuator

(2) Heater Unit

(3) Mode Actuator

(4) Blower Unit

(5) Intake Actuator

The actuator changes the motor speed using the

gear and drives each door rotating the output axis

united with the sliding contact.

860RX013

826RY00001

This illustration is based on RHD

860RX012

This illustration is based on RHD

Legend

(1) Out put Axis

(2) Motor

(3) Printed Circuit Board

(4) Sliding Contact

The mode and mix actuators are common actuators

with the built-in potentiometer. For the intake

actuator, the contact switch type is selected.

The potentiometer is a register assembled to the

printed circuit board of the mix and mode

actuators. It detects the air mix door position

specified by rotation of the output axis as a ratio of

the variable terminal (VM) voltage against the

reference voltage (VDD: 5V), then signals the value

to the automatic heater/air conditioner control unit.

•Movement of Mix Actuator

Position of the air mix door is determined by the

controller on the automatic heater/air conditioner

control unit.

As the heat or cool side of the controller is

grounded, the transistor on the driver is activated

and, thus, the motor rotation is turned on. The

sliding contact connected to the motor sends the

position detection signal from the potentiometer

to the automatic heater/air conditioner control

unit. As the set temperature and interior

temperature are balanced, the controller returns

to the neutral and the motor rotation is stopped.

860RW026

C01RX016

Potentiometer

Connection

Position

Detection

Block

Automatic Heater / Air

Conditioner Control Unit

Controller

Sliding Contact

Full Heat PositionTerminal Plate

Full Cool Position

Driver

Cool Side

Heat Side

C01RY00016

Full cool

0.5

1.0

50 100%

Aperture of air mix door

Voltage ratio VM/VDD

Full heat

Full heat VDD

–

I-45 Rotation

(+) side (–) side direction Remarks

8 6 Clockwise Full heat side

6 8 Counter Full cool side

clockwise

•Movement of Mode Actuator

As target position of the mode door is decided on

the controller of the control unit, the control unit

reads the position detection signal from the

actuator to select the clockwise or counter

clockwise motor rotation direction.

Grounding the controller VENT or DEF side after

the direction selection activates the transistor on

the driver, thus turning on the motor rotation.

Accompanying the motor rotation, the sliding

contact rotates, too. When the target position is

reached, the controller on the control unit returns

to the neutral and the motor stops.

•Movement of Intake Actuator

The controller on the automatic heater/air

conditioner control unit selects an intake mode to

be used.

As the Terminal No.5 is grounded via the

sliding contact on the terminal plate, the

transistor on the driver is activated, thus turning

on the motor rotation. Then, accompanying

move of the motor, the sliding contact rotates

until grounding of the Terminal No.5 is

removed, thus stopping the motor. I-49

I-49

Driver

Controller

DEF side

VENT

side

Position

detection

block

Control unit

Sliding

contact

Actuator side

78910

HLHL

HHHL

HHLL

HHLH

HLLH

HLHH

LLHH

LHHH

LHLH

Interconnected

motor

VENT

Mid point between VENT - B/L

B/L

Mid point between B/L - FOOT

FOOT

Mid point between FOOT - D/F

D/F

Mid point between D/F - DEF

DEF

DEF 7

C01RX017

6543

REC

MIX

FRESH

Com

4++

—

Terminal Plate

Auto A/C

Control Unit

(Actuator Side)

Driver Controller

Sliding Contact

Connected

C01RX006

Conducting pin Rotation

(+) side (–) side direction Remarks

5 1 Clockwise VENT to

DEF direction

1 5 Counter DEF to

clockwise VENT diction

Grounding Rotation

terminal direction Remarks

No.5 Clockwise RE-CIRCULA

TION→MIX

→FRESH

I-49

OVERVIEW OF AUTOMATIC CONTROL OF

FULL AUTOMATIC AIR CONDITIONER

The full automatic heater and air conditioner on this

vehicle has the following features:

•Interior temperature control.

•Air flow control.

•Mode (blow port) control.

•Intake (switching between fresh air and interior

air) control.

•Heater start timing control.

•Cooler start timing control.

•Evaporator anti-freeze control.

1. Interior Temperature Control

The automatic heater/air conditioner control unit

operates on the setup temperature signal from

the temperature control switch and other sensor

signals to derive the total signal. Then, the

control unit compares this signal against the

signal from the potentiometer to determine

rotation direction of the mix actuator. The mix

actuator moves the air mix door to the aperture

specified by the total signal so that the specified

interior temperature is achieved.

If the compressor is turned off in the A/C (air

conditioning) mode, aperture of the air mix door

is offset according to the outside air temperature

or the specified interior temperature. This

function removes the difference in the blowing

temperature in this state and that of when the

compressor is turned on.

When FH or FC is selected for the setup

temperature, the air mix door is accordingly

fixed to the Full Heat or Full Cool mode.

When the VENT mode is selected, aperture of

the air mix door is controlled so that excessively

heated air may not be blown from the VENT

blow port.

140 104 68 32

Air mix door aperture

Full cool

Heater

side

Restriction on the

aperture enabied

in the VENT mode

Air conditioning

ON mode

Full heat

Set temperature

signal

Mix

actuator

Potentio

meter

Air mix door

In car sensor

Ambient sensor

Sun sensor

Control unit

Air conditioning

switch

Set up temperature

signal

Air conditioning

OFF mode

Total signal Cooler

side

C01RY00011

2. Air Flow Control

•In the Auto Mode

The automatic heater/air conditioner control unit

operates on the setup temperature signal and

other sensor signals to derive the total signal.

Then, the control unit adjusts base potential of

the power transistor to match it to the voltage

pattern of the target fan so that stage-less fan

speed control can be achieved.

When solar radiation quantity is detected in the

VENT or B/L mode, the control unit increases the

minimum fan voltage to offset.

When FH or FC is selected from the temperature

control switch, air flow is accordingly fixed to

MAX HI or AUTO HI.

•In the Manual Mode

Air flow specified from the fan switch is entered

to the automatic heater/air conditioner control

unit as the manual signal. The signal modifies

the air flow to the level specified from the fan

switch so that the required fan voltage is

attained.

3. Mode (Blow Port) Control

The automatic heater/air conditioner control unit

operates on the setup temperature from the

control switch, and temperature and solar

radiation quantify from the sensors to determine

the total mode control signal. According to the

pattern specified by this signal, the control unit

selects either one of the VENT, BI-LEVEL, FOOT

or DEF/FOOT mode.

The mode actuator determines the rotation

direction comparing the target position against

the current position being determined by the

position detection signal.

When FH or FC is selected for the temperature

from the temperature control switch, mode is

accordingly fixed to the VENT or FOOT.

•In the manual operation of the mode switch, you

can select a desired blow port mode pressing

the corresponding mode switch.

•Operating the DEF mode switch selects the DEF

for the blow port mode.

4.5

(V)

MAX

HI Relay

Power

transistor

4.8

10.5

MAX HI

Set up

temperature signal

Control unit

In car sensor

Ambient sensor

Sun sensor

Mode control

signal

Fan switch

AUTO HI

Heater

side Cooler

side

Total signal

VENT mode

Blower fan motor terminal voltage

C01RY00008

Mode control

DEF / FOOT

Set up temperature

signal

Mode actuator

Mode door

Position

detection

switch

Control unit

In car sensor

Sun sensor

Air conditioning

switch

Mode control

signal

Ambient sensor

FOOT

BI-LEVEL

VENT

Heater

side Cooler

side

Mode total signal

C01RY00009

4. Intake (Fresh air/interior air switching) Control

In the Full Auto mode, the automatic heater/air

conditioner control unit operates on the setup

temperature signal and other sensor input

signals to derive the total signal. According to

the pattern specified by this signal, the control

unit provides the intake control.

When the fan is turned off or the A/C (air

conditioning) is turned off, the intake is fixed to

the FRESH mode.

When FC or FH is selected from the control

switch, the intake mode is accordingly fixed to

the RECIRC or FRESH.

•In the Manual Operation

Pressing the FRESH (fresh air intake) or the

RECIRC (room air circulation) accordingly selects

the FRESH or RECIRC mode.

•When the DEF Mode Switch is depressed

The intake mode is fixed to the FRESH. When

the MANU REC is selected, however, the mode

is fixed the RECIRC.

•When the Mode Switch is depressed

If the automatic intake control is selected, the

intake is fixed to the currently selected mode.

5. Compressor Control

In the automatic control mode, the automatic

heater/air conditioner control unit turns on or off

the compressor with the evaporator anti-freeze

mechanism using the duct sensor. And, when

outside air is detected to be low through the

ambient sensor signal, the control unit turns off

the compressor using the compressor control

function.

•Manual Control

In the automatic control mode, pressing the A/C

(air conditioning) switch turns off the

compressor.

•Pressing the DEF mode switch automatically

turns on the compressor.

Intake door open / close

RECIRC

Setup temperature

signal

Intake

actuator

Position

detection

switch

In car sensor

Ambient sensor

Sun sensor

Compressor

ON / OFF

Fan ON / OFF

Intake switch

Control unit

Intake door

MIX

FRESH

Heater

side Cooler

side

Total mode signal

C01RY00012

Ambient sensor

Control unit

Pressure switch

Thermo switch relay

ECM

Compressor relay

Compressor

Electronic

thermostat

Air conditioning

switch

Set up temperature

signal

C01RY00010

6. Heating Start Timing Control

When the automatic heater/air conditioner is

started, heating is turned on under following

conditions.

•The detected temperature of thermo unit is

136°F or less.

•The temperature setting signal and the total

signal by each sensor meet the condition of

heating.

When the detected temperature by the coolant

temperature sensor is 136°F or less the blower

fan motor is set to work at low speed and the

"DEF" mode is selected.

When the detected temperature by the coolant

temperature sensor is 77°F or more, the blow

mode changes automatic control. And the

blower fan speed is controlled to be lineally up

from "LO" to "MAX HI".

7. Cooling Start Timing Control

When the automatic heater/air conditioner is

started, cooling is turned on under following

conditions.

•The in car sensor is 86°F or more.

•The temperature setting signal and the signals

from each sensor meet the specified condition.

The blower fan speed is set to "LO" for

maximum 7 seconds when cooling start

conditions meet, and then, is controlled to be

lineally up to "MAX HI" by 5.32%/S.

Ignition swich

"ON" Time

Blower voltage to turn

on the cooling

7 SEC maximum

3 SEC

100%

(MAX HI)

33.5%

(LO)

5.32%/S

C06RY00001

33.5%

(LO)

2.63%/S

Mode

DEF

Auto

Mode

100%

(MAX HI)

Ignition

switch "ON"

Thermo Unit 58¡C(Gasoline)

52¡C(Diesel)

Time

840RY00009

TROUBLESHOOTING

Troubleshooting - It's Overview and Procedures

The full automatic heater and air conditioner equips with the "Self-Diagnosis Function" to check its major

components.

This function makes access to the sensors, actuators and blower fan motor system easier when checking

them up and, when a failed part is located, this function restores its original performance.

When implementing the troubleshooting, this self-diagnosis function narrows the range to be searched at

the first step, then check relevant parts one by one according to the "Checking Procedures by Failed

Location" As for a location this function is unappreciable, the system accurately determines characteristics

of a given trouble and checks relevant parts according to the "Checking Procedures by Failed Location".

The following illustrates basic troubleshooting flow.

1. Basic Troubleshooting Flow

Occurrence of a trouble

Refer to the check list for

the inspection. Locate the failed location.

Check the failed part.

Correction

Troubleshooting by the

self-diagnosis function.

Reference the "Check

Procedure by Failed

Location" for the inspection.

Reference the "Check

Procedure by Failed

Location" for the inspection. Correction

Check the cooling / heating

cycles.

End

Check if the automatic

heater / air conditioner

control unit indicator LED

is turned on.

Check the power supply and

circuit on the automatic

heater / air conditioner control

unit.

Troubleshooting not relying

on the self-diagnosis

function(troubleshooting

by failure type).

F01RX009

Techline

Check of Auto Amplifier (Automatic air conditioner control unit) Power Supply System

•This check is required because a trouble on the auto amplifier (control unit) power supply circuit or

grounding circuit prevents accurate troubleshooting.

Check of auto amplifier

power supply circuit and

grounding circuit.

Chart A

B-18

FL-1 Main

80A

0.5G/R

I-32

C-16

10A

0.3R/W

0.5BR

Backup

Power supply (12V)

Unit ground

Automatic heater/air conditioner control unit

B-18 B-36 H-14

C-20

10A A/C

Relay:

Heater and air

conditioner

0.5B

1.25B

Lighting switch

H-14 1H-26 9

H-26 14

H-27 20

H-16 14

B-36

H-16

H-26 H-27 I-32

109876 54321

2221201918 151413121117 16

12345

1112131415

678910

181920212216 17

101112131415

12345

17181920

6789

9876

20191817 16

1415

10 20

12 34 43 21

12111098765

1314151617181920 12345678

9 10111213141516

D08RY00175

Chart "A" : Check of Auto Amplifier Power Supply System

NO Harness disconnection or improper grounding.

NO Harness disconnection or trouble on lighting

switch.

NO Harness disconnection or improper grounding.

Turn off ignition switch.

Power supply system is free of

trouble.

YES

Is battery voltage present between chassis

harness connector terminal No.7

and ground? I-32

Is battery voltage present between

chassis harness connector No.8

and ground? I-32

Are chassis harness connector No.16

and body ground conducted?

B-18 I-32

Turn on ignition switch (engine is started).

Turn on lighting switch.

Is battery voltage present between chassis

harness connector No.10 and

ground? I-32

Performance and Movement checklist for Automatic Air Conditioner Related Parts

Start the engine, and when the engine coolant reached 60°C check performance and movement of the

related parts according the following checklist.

1. Performance Check Using the Manual Switch

Checking Approach

No. Item Acceptance criteria

Condition Operation

Blowing

temperature

(check movement

of air mix door)

Airflow volume

(check movement

of the mode door)

Set temperature to

25.0°C. (1) Turn the fan knob

off.

(2) Turn the fan knob

from LOW to HI.

(1) The fan shall be stopped, thus

stopping air blow, too.

(2) Airflow volume shall change

from LOW to HI.

Blowing

temperature

(check movement

of the mode door)

Set temperature to

25.0°C.

Set the fan knob to HI.

Press the mode switch

to change the blow port

mode sequentially from

the VENT through BI-

LEVEL, FOOT up to

DEF.

LED corresponding to each mode

shall be turned on and the blow

port mode shall be switched

smoothly.

The

interior/outside air

switching mode

(check movement

of intake door)

Set temperature to

25.0°C. Turn the LED off using

the interior/outside air

switch (this introduces

the outside air intake

mode). Then, the set

fan knob to HI and

press the

interior/outside switch

to turn on the LED.

The LED indication shall be

switched from OFF to ON

accompanying a change in air

blowing sound.

Compressor Set the temperature to

FC. (Outside air

temperature is 0C or

above and interior

temperature at ordinary

temperature.)

Press the "OFF" switch.

(1) Press the Auto

switch.

(2) Press the Air

Conditioner switch.

(1) As the fan knob is set to the

Auto position, the A/C switch

LED shall come on and the

compressor shall be turned on.

(2) As the A/C LED comes off, the

compressor shall be turned off.

Auto switch must be

turned on

(FAN-AUTO

MODE-AUTO)

(1) Select FC for the

setup temperature.

(2) Select FH for the

setup temperature.

→Then, select the

MAX Control.

(1) Cold air shall be blown out.

(2) Hot air shall be blown out.

Checking Approach

No. Item Acceptance criteria

Condition Operation

Change the

temperature gradually

starting with 20°C up to

30°C.

The following phenomena shall be

recognized.

•Temperature of blown air: Cold

air is changed to hot air.

•Change in the air flow volume.

•The blow port mode LED

indication changes in the

following sequence:

Select FH for the

temperature.

Cold air shall be blown out.

The following LEDs shall come on.

• Blow port mode :

• Fan speed: Max Hi

Select FC for the

temperature.

The LED shall come on.

Cold air shall be blown out.

The following LEDs shall come on:

• Blow port mode :

• Intake mode

• Fan speed : MAX Hi

• A/C

1 Full Auto function FAN KNOB “AUTO”

MODE SW “AUTO”

2. Check of Full Auto Function

(VENT) (FOOT)(BI-LEVEL)

F01RX003

F01RX002

F01RX004

TROUBLESHOOTING WITH SELF-DIAGNOSIS FUNCTION

1. Overview of Self-Diagnosis Function

The self-diagnosis is implemented in 3 steps for each target. For detail of check procedure contained in

each step, refer to the relevant section of "Check Procedure by Failed Location" listed in the Self-

Diagnosis Operation Procedure.

For turning on the self-diagnosis function and switching of the check step, refer to the flow chart given

below. You can reset the self-diagnosis function by turning the ignition switch off or turning the DEF

switch on for 3 seconds.

2. Self-Diagnosis Operation Procedure

While holding both the Auto switch and the DEF switch on the

automatic heater/air conditioner panel, turn the IG off and then

on.

Does the A/C LED flash every 0.5 second interval?

Press the A/C switch once. (The past trouble

diagnosing function will

be turned on.)

Does the A/C LED flashes every 0.5 seconds?

Does each output equipment functions normally according to

operation of the temperature setting lever?

Press the DEF switch for 3

seconds consecutively or turn on

and off the IG.

Failure on the

output equipment

or the harness.

Preparations

(1) Set the IG to the OFF mode.

(2) Apply 60W bulb light to the sun sensor.

(3) Set the temperature setting lever on the automatic heater/air

conditioner panel to the center position (25C).

(4) Set the fan switch on the same panel to the Auto position.

End of the self-diagnosis.

(The current trouble diagnosing function will be turned on

approximately in 10 seconds.)

YES

Refer to *1.

Refer to *2.

*1. Displaying the Current Trouble Diagnosing Table

Start the engine while holding down both the Auto switch and the DEF switch on the control panel, and

the table will appear in approximately 10 seconds to the indicator lamp (LED) of the air conditioning

switch. Result of the diagnosis along the following 9 items will be shown one by one in 0.5 second

interval irrespective of presence or absence of a trouble for a given item. When the display 9 items is

completed, it is repeated with 3 seconds of interval in between. A failed item is indicated by flashing of

the LED that is repeated 3 times within 0.5 seconds. If a trouble is indicated, you can locate the failed

section by knowing when in the total sequence it has been displayed.

Items for Current Trouble Diagnosis

As shown above, display of result along nine items is repeated with 3-second interval in between.

Note 1: When checking the solar radiation sensor, apply sufficient light using a 60W bulb.

Otherwise, it can be diagnosed as failed.

Note 2: If the temperature setting lever is set on both ends (one set to 18°C, blue scale = Full cool and

the other to 31°C, red scale = Full hot), they can be diagnosed as failed.

Note 3: Likewise, the fan switch can be diagnosed as failed if set on both ends.

LED on

LED off

Indication for presence

of a trouble Indication for normal state

0.5 0.5 0.5 3 seconds interval

OFF

Display pattern Failed part

Normal pattern

In car sensor

Ambient sensor

Sun sensor (Note 1)

Duct sensor

Temperature control lever (Note 2)

Fan switch (Note 3)

Mix actuator

Mode (blow port) control

Intake (fresh air/interior air switching) control

F01RX010

F01RY00008

*2. Displaying the Past Trouble Diagnosing Table

The past trouble diagnosis displays only the items on which trouble has recurred 16 times in the past.

If you press the air conditioning switch once while the current trouble diagnosis is taking place, display

of the past trouble diagnosis will appear on the indicator lamp (LED) of the air conditioning switch.

Results of the diagnosis along the following five items are displayed one by one in 0.5 second interval

irrespective of presence or absence of a trouble. A failed item is indicated by flashing of the LED that is

repeated 3 times within 0.5 seconds. You can locate the failed section by counting in what sequence it

has been displayed.

Items for Past Trouble Diagnosis

LED on

LED off

Indication for presence of a trouble Indication for normal state

0.5 0.5 0.5 3 second interval

Display pattern

OFF Normal pattern

In car sensor

Ambient sensor

Sun sensor

Duct sensor

Mix actuator

Failed part

F01RX011

F01RY00007

*3. Check of Output Equipment

FAN

MIX

MODE

DOOR

INTAKE

DOOR

SET UP

TEMPERATURE

100

(%)

33.5

F/H

VENT

B/L

FOOT

D/F

DEF

REC

MIX

FRE

F/C 20 21 22 23 24 25 26 27 28 29 30 F/H

(%)

F/C

F01RY00001

Independent check of sensors

Replace the control unit.

Sensors Allowable range Check method

In car sensor

Ambient sensor

Sun sensor

Refer to the sensor resistance curve.

100 ohms maximum in forward and 0.02 mA

minimum when exposed to 60W incandescent lamp.

Chart 1

Chart 2

Chart 3

Replace the harness and

connector.

Replace the sensors.

Check the related harness and

connector

Normal ?

YES

INSPECTION BY FAILED LOCATION

Inspection of the Sensors

When the self-diagnosis function has determined that trouble is present on the sensors, check them

according to the following flow chart.

F01RY00005

Chart 1: In Car Sensor

NO Replace the sensor.

NO Disconnection of the harness.

Failure on the automatic heater/air

conditioner control unit.

YES

Disconnect the in car sensor connector (I-34).

YES

Is the sensor performance normal? (refer to

the later section on "Check Up")

Are conduction provided between the

following connector terminals on chassis

harness side?:

No.3 and No.1 .

No.4 and No.11 .

I-33I-34 I-33I-34

I-33 I-34

0.3 BR/B

0.5 B/L

In car Sensor

Auto A/C Control Unit

(In car Sensor)

(Sensor GND) 4

I-33 I-34

12 43

D08RY00174

Chart 2: Ambient Sensor

NO Replace the ambient sensor.

NO Failure on the harness.

Connect the ambient sensor connector.

Replace the automatic heater/air conditioner

control unit.

YES

Disconnect the Ambient sensor connector

(C-86).

YES

Is performance of the ambient sensor

normal? (Refer to the later section on

"Check Up".)

Is resistance between the following

connectors normal?

No.2 and No.11 .

I-33I-33

I-33C-86

H-24

0.3 LG/B

0.3 B/L

Ambient Sensor

Auto A/C Control Unit

(Ambient Sensor)

(Sensor GND) I-33

0.3 LG/B

0.3 B/L

H-24

C-86

1718161514

7865

121311109

4132

5678

15161718 14

2341

10111213 9

D08RY00176

Chart 3: Sun Sensor

NO Replace the sun sensor.

NO Replace the harness.

Replace the automatic heater/air conditioner

control unit.

YES

Disconnect the sun sensor connector (I-35).

YES

Is performance of the sun sensor normal?

(Refer to the later section on "Check Up".)

Is the conduction provided between the

following chassis harness side connector

terminals?

No.3 and No.1 .

No.11 and No.2 .

I-35I-33 I-35I-33

0.3 LG/W

0.3 B/L

Sun Sensor

Auto A/C Control Unit

(Sun Sensor)

(Sensor GND)

I-33

I-35 1

I-35 2

I-33 I-35

2 1

D08RY00177

Inspection of the Intake Actuator System

B-19 I-32

B-36

H-26 H-13

I-49I-33

12345678

9 10111213141516

101112131415

12345

17181920

6789

9876

20191817 16

1415

B-36

FL-1 80A

MAIN

11 0.5 L/O

STARTER RELAY

I-33

0.3 L/R

0.5 L/W

0.3 B/L

0.3 L/Y

Intake Actuator

Auto A/C Control Unit

BATT.

(Intake Actuator)

GND(COM)

CIRC

FRESH

MIX

I-32

0.5 BR0.5 BR3.0 L/R

C-20 10A

A/C

I-49

H-13

I-49

H-26 14

B-19

3456

123

456

Type of the

trouble

Control failure.

Chart B

Does not work at all.

Chart A

D08RY00178

Chart A: Does Not Work At All

NO Failure on the power supply circuit.

NO Failure on the actuator.

NO The harness is disconnected.

NO Replace the automatic heater/air conditioner

control unit.

YES

Turn on the ignition switch (the engine is

started).

Switch between the fresh air intake and the

interior air circulation.

Failure on the intake link unit (intake door

lock).

Is the battery voltage present between the

chassis harness side connector terminal

No.3 and the ground?

I-49

Is the battery voltage present between

the chassis harness side connector

terminal No.4 and the ground?

I-49

Is the battery voltage present between

the chassis harness side connector

terminal No.11 and the ground?

I-32

During the above switch operations, did

the voltage between the chassis harness

side connector terminal No.11 and

the ground go below 0.5V? I-32

Chart B: Failure on the Intake Control

NO The harness is disconnected.

NO Failure on the automatic heater/air

conditioner control unit.

NO Failure on the automatic heater/air

conditioner control unit.

YES

Turn on the ignition switch (the engine is

started).

Disconnect the intake actuator connector

(I-49).

Failure on the intake actuator.

Is the intake actuator stopped?

Is conduction provided between the

following chassis harness side connector

terminals?

No.5 and No.11 .

No.6 and No.12 .

No.1 and No.13 .

No.2 and No.14 .

I-33I-49 I-33I-49 I-33I-49 I-33I-49

Is voltage (approximately 5V) present

between the following?

No.12 and the ground.

No.13 and the ground.

No.14 and the ground.

I-33

Inspection of the Mix Actuator System

H-67I-32 I-33

12345678

9 10111213141516

I-45

I-32

0.3 V/W

I-33

11 3

0.5 B/L

0.3 V

15 2

0.3 V/G

24 8

0.3 V/R

I-45

3 KW

Heat

(Potentio Meter)

Cool

CoolHeat

Mix Actuator

Auto A/C Control Unit

HEAT TO COOL

Cool side

Heat side

COOL TO HEAT

GND

(Mix Potentio Meter)

5 V

0.3 V/W

0.3 B/L

0.3 V

0.3 V/G

H-67

0.3 V/R

89712 3

4567

123

84567

Type of the

trouble

Control failure.

Chart B

Does not work at all.

Chart A

D08RY00179

Chart A: Does Not work At All

NO The harness is disconnected.

NO Replace the automatic heater/air

conditioner control unit.

NO Replace the automatic heater/air

conditioner control unit.

YES

Turn on the ignition switch (the engine is

started).

Disconnect the mix actuator connector

Short-circuit he chassis harness side

connector terminal No.3 and No.7

I-45 I-45

I-45

Using the temperature control lever,

select FC for the temperature.

Using the temperature control lever,

select FC for the temperature.

Failure on the actuator.

Is the battery voltage present on a regular

interval basis between the chassis

harness side connector terminals No.6

(+) and No.5 (-)?

I-32I-32

Is conduction provided between the

following chassis harness side connector

terminals?

No.6 and No.6 .

No.5 and No.8 .

I-45I-32 I-45I-32

Is the battery voltage present on a regular

interval basis between the chassis

harness side connector terminals No.6

(-) and No.5 (+)?

I-32I-32

Chart B: Mix Actuator Control Failure

NO Replace the actuator.

NO The harness is disconnected.

NO Mix actuator control failure due to the

failed sensor.

YES

Turn on the ignition switch (the engine is

started).

Replace the automatic heater/air conditioner

control unit.

Is conduction provided between the

following chassis harness side

connector terminals?

No.3 and No.11 .

No.7 and No.5 .

No.2 and No.15 .

I-33

I-45 I-33I-45 I-33I-45

Is sum of the voltages between the

following chassis harness side connector

terminals approximately 5V?

Voltage between No.15 and No.5

plus voltage between No.5

and No.11 .

I-33 I-33I-33 I-33

Does the self-diagnosis function (the

current trouble display) indicate failure

on the mix actuator potentiometer?

Is full stroke of the air mix door available

when you selected FH or FC using the

temperature control lever? Failure on the air mix door or the link

unit.

Inspection of the Mode Actuator System

H-26

101112131415

12345

17181920

6789

9876

20191817 16

1415

H-25

I-32 I-33

12345678

9 10111213141516

I-32

0.3Y/BR 0.3Y/BR

B-69

I-33

DEF TO VENT

VENT side

DEF side

MODE1

MODE2

MODE3

MODE4

MODE5

S.GND

25 11

0.5Y/G 0.3Y/G12

0.3GR 0.3GR

0.3GR/G

0.5GR/R 0.5GR/R19

0.5GR/G 0.3GR/G5

0.3GR/L 0.3GR/L1

0.5B/L 0.3B/L4

Auto A/C Control Unit

VENT

FOOT

DEF

B/L

D/F

Mode Actuator

(Heater Unit)

VENT TO DEF

H-25

H-26

H-25

H-26

0.5B/L 8 H-25

B-69

897

10 9 8 7 6 5 4 3 2 1

2221201918 151413121117 16

12345

1112131415

6 7 8 9 10

181920212216 17

Type of the

trouble

Control failure.

Chart B

Does not work at all.

Chart A

D08RY00180

Chart A: Does Not Work At All

NO The harness is disconnected.

NO Replace the automatic heater/air

conditioner control unit.

NO Replace the automatic heater/air

conditioner control unit.

YES

Turn on the ignition switch (the engine is

started).

Disconnect the mode actuator connector

(B-69).

Select VENT pushing the mode actuator

switch.

Turn on the DEF mode switch.

Failure on the actuator.

Is the battery voltage provided on a

regular interval between the following

chassis side connector terminals?

No.3 (+) and No.4 (-).

I-32I-32

Is conduction provided between the

following chassis harness side connector

terminal?

No.1 and No.4 .

No.5 and No.3 .

I-32B-69 I-32B-69

Is the battery voltage provided on a

regular interval between the following

chassis harness side connector

terminals?

No.4 (+) and No.3 (-).

I-32I-32

Chart B: Mode Actuator Control Failure

NO The harness is disconnected.

NO Replace the actuator.

NO Failure on the mode door or the link unit.

YES Mode control failure due to the failed

sensor.

YES

Turn on the ignition switch (the engine is

started).

Replace the automatic heater/air conditioner

control unit.

Is conduction provided between the

following chassis harness side

connector terminals?

No.9 and No.11 .

No.3 and No.10 .

No.4 and No.8 .

I-33B-69 I-33B-69 I-33B-69

Is sum of the voltages between the

following chassis harness side connector

terminals approximately 5V?

Voltage between No.15 and No.1

plus voltage between No.15

and No.11 .

I-33 I-32I-32 I-32

Does the mode work normally through

manual operation?

Is full stroke available from the mode

door when the defrost mode and vent

mode are selected?

Inspection of the Fan Motor System

H-26

101112131415

12345

17181920

6789

9876

20191817 16

1415

H-20

I-32 I-33

12345678

9 10111213141516

B-1 B-5 I-50B-36

I-33

19 I-50

0.3 GR

2.0L/B

I-50

B-5

I-51

B-1 2.0 B 1

2 B

2 L/B

0.3 BR

0.5 L/B 2 L/B

2 B

0.3 GR/L

3.0 L3.0 L/R

C-19 25A

FUSE

C-20 10A

FUSE

Blower Motor

Max High

Relay

Power

Transistor

Auto A/C

Control Unit

B-36

I-51

I-51I-51

I-32

I-33

H-20

H-26

I-51

H-20 2

1 2

D08RY00181

Chart A: Fan Does Not Rotate At All

NO Failure on the power supply system.

NO Failure on the ground or the harness is

disconnected.

NO Replace the fan motor.

YES

Turn on the ignition switch (the engine is

started).

Refer to Charts B and C.

Is the battery voltage present between the

chassis harness side connector terminal

No.2 and the ground?

B-5

Are the chassis harness side connector

terminals No.4 and the ground

(No. ) conducted?

B-1 I-51

Is the battery voltage present between

the chassis harness side connector

terminals No.1 and No.2 ?

B-5B-5

Type of trouble

The fan does not

rotate in any mode

other than MAX HI. The fan does not stop.

Chart B Chart C Chart D

The fan does not

rotate in the MAX HI

mode.

The fan does not

rotate at all.

Chart A

Chart B: Fan Does Not Rotate in MAX HI Mode

NO The harness is disconnected.

YES

NO NO

YES

Turn on the ignition switch (the engine is

started).

Set the fan switch to the MAX HI.

The harness is

disconnected. Failure on the automatic

heater/air conditioner

control unit.

Failure on the MAX

HI relay. Failure on the

ground or the

harness is

disconnected.

Is the battery voltage present between the

chassis harness side connector terminal

No.12 and the ground?

I-32

Are the chassis harness side connector

terminal No.4 and the body ground

(No. ) conducted?

B-1 I-51

Are the chassis harness side connector

terminals No.1 and No.2

conducted? I-51B-5

Is the battery voltage present between

the chassis harness side connector

terminal No.1 and No.3 ?

I-51I-51

Chart C: Fan Does Not Rotate In Any Mode Other Than MAX HI

NO Replace the power transistor.

NO Failure on the ground or the harness is

disconnected.

NO The harness is disconnected.

YES

Failure on the automatic heater/air

conditioner control unit.

Is the power transistor performance

normal? (Refer to the later section on

"Check Up".)

Is the battery voltage present between

the chassis harness side connector

terminal No.3 and the ground No.

B-1 I-50

Is conduction provided between the

following chassis harness side connector

terminals?

No.1 and No.1 .

No.1 and No.17 .

I-33B-5 I-50B-5

Are the chassis harness side connector

terminals No.2 and No.19

conducted? I-33I-50

Chart D: Fan Does Not Stop

NO Replace the power transistor.

NO Replace the relay.

YES

Turn on the ignition switch (the engine is

started).

YES

Is the power transistor performance

normal? (Refer to the later section on

"Check Up".)

Is the MAX HI relay performance

normal? (Refer to the later section on

"Check Up".)

Is the battery voltage present between

the chassis harness side connector

terminals No.1 and No.3 ?

I-51I-51

The chassis harness side connector

terminals No.1 and No.2 , or

No.1 and No.1 is short

circuited. I-50B-5 I-51B-5

Failure on the automatic heater/air

conditioner control unit. Or, the harness

line is short circuited between the chassis

harness side connector terminals No.3

and No.12 .

I-32I-51

Inspection of the Magnet Clutch System

6VE1 Engine

I-32

C-1 C-3I-33

E-3 E-19

12345678

9 10111213141516

B-19 C-25

B-36

H-14

C-19

25A

BLOWER

MOTOR

C-20

10A

A/C

FL-1

80A

MAIN

Heater

Relay

B-36

H-13

0.3

0.85

W/G

0.85

W/R

3.0

L/R

0.5

1.25

B-19

BODY-LH

B-36

BATT.(+)

Blower

Motor Intake

Actuator

STARTER

RELAY(1)

0.5

BR 0.5

0.5

G/W

0.5

P/G

0.5

P/G

0.5

G/O

0.5

G/O

PCM

(C3-E15)

31 13

COMP-F/B

0.5

BR/Y

0.3

G/B

0.5

G/B

0.5

BR/Y

0.5

Triple

Pressure

Switch 0.5

A/C

Thermo Relay

Auto A/C Control Unit

X-5

H-16 17

H-16

I-32

I-33

X-5

H-24

H-41

C-25

X-5 X-5

X-5

H-16

A/C

Compressor

Relay

Magnetic

clutch

X-7

X-7 4

X-7

PCM

(C-1-B14)

E-3

H-6

H-41

Engine

Coolant

Temperature

Sensor

ENGINE COOLANT

TEMPERATURE GAUGE

0.5

Y/B 0.5

Y/B

0.5

Y/B

E-19

H-6

H-24

I-33

B-36 X-5 X-7

H-14

H-16

H-24

H-13

H-6 H-41

3412 111

123

456

10 9 8 7 6 5 4 3 2 1

2221201918 151413121117 16

12345

1112131415

6 7 8 9 10

181920212216 17

H-41

4321

8765

12 11 10 9

16 15 14 13

1234

5678

9101112

13 14 15 16

1718161514

7865

121311109

4132

5678

15161718 14

2341

10111213 9 A1 A2 A3 A4 A5 A6 A7A8 A9

A10A11A12 A13A14 A15 A16

B1 B2 B3 B4 B5 B6 B7 B8 B9

B10 B11 B12 B13 B14 B15 B16

E1 E2 E3 E4 E5 E6 E7 E8 E9

E10 E11 E12 E13 E14 E15 E16

F1 F2 F3 F4 F5 F6 F7 F8 F9

F10 F11 F12 F13 F14 F15 F16

D08RY00182

Chart A: Magnet Clutch Does Not work

NO The harness is disconnected.

NO Replace the failed relay.

NO Failure on the power supply system.

NO Replace the fuse.

YES Failure on the magnet clutch.

NO Replace the electronic thermostat.

YES

The harness is disconnected.

Failure on the pressure switch or

refrigerant is insufficient.

Turn the A/C (air conditioner) switch on.

Are the pressure switch side connector

terminals No.1 and No.2

conducted? C-25C-25

Are relays normal?

Is fuse (C-20) 10A normal?

Is the electronic thermostat normal?

Is the battery voltage present between

the chassis harness side connector

terminal No.1 and the ground?

E-3

Is the battery voltage present between

the chassis harness side connector

terminal No.1 and the ground.

C-25

Is the battery voltage present between

the chassis side relay terminal No.3

and the ground, and No.1

and the ground? X-7X-5

YES

Turn the ignition switch off.

Is conduction provided between the

following chassis harness side connecter

terminals?

No.2 and No.2 .

No.4 and No.1 .

E-3X-7 X-7X-5

Turn the ignition switch on (the engine is

started).

Magnet clutch does not work

Chart A

Type of trouble

NO The harness is disconnected.

YES

Failure on PCM (see Chapter 6E for A/C

control with PCM).

Is the battery voltage present between the

chassis harness side connector terminal

No.14 and the ground?

I-32

Is conduction provided between the

following chassis harness side connector

terminals?

No.B14 and No.3 .

No.E15 and No.4 .

X-5C-3 X-7C-1

Disconnect the connector on the

automatic heater/air conditioner control

unit.

I-32

The harness is disconnected between No.1

and No.14 .

I-32X-5

YES

When you turned on the "Auto" switch,

does the battery voltage appear

between the chassis harness connector

terminal No.14 and the ground?

I-32

Failure on the automatic heater/air conditioner

control unit.

4JX1 Engine

Magnet clutch does not work.

Chart A

Type of trouble

C-25

0.5 BR

C-25

X-5X-5

0.5 P/G

FL-1 MAIN

80A C-20

10A A/C

0.5 G/W

0.5 G/O

C-25 E-27 H-16

Pressure

switch

Relay:

Air conditioning

thermostat

Automatic heater/air conditioner

control unit

Relay:

Air conditioning 0.5 BR

I-32 14

Fan ON

I-32 X-5

E-27

Magnet

clutch

B-36

H-16 16

11718161514

7865

121311109

4132

5678

15161718 14

2341

10111213 9

12345678

9 10111213141516

D08RY00183

Chart A: Magnet Clutch Does Not Work

NO Replace the fuse.

NO Replace the failed relay.

NO Replace the electronic thermostat.

YES Failure on the magnet clutch.

NO The harness is disconnected.

NO Failure on the power supply system.

YES

Is fuse C-20 (10A) normal?

Are relays normal?

YES

Is the electronic thermostat normal?

YES

Turn the A/C (air conditioner) switch on.

Is the battery voltage present between the

chassis harness side connector terminal

No.1 and the ground?

E-27

Is the battery voltage present between the

chassis harness side connector terminal

No.1 and the ground.

C-25

YES

NO Failure on the pressure switch or refrigerant is

insufficient.

NO The harness is disconnected.

Is the battery voltage present between the

chassis side relay terminal No.1

and the ground? X-5

Are the pressure switch side connector

terminals No.1 and No.2

conducted? C-25C-25

YES

Failure on the automatic heater/air

conditioner control unit.

NO The harness is disconnected.

Is conduction provided between the

chassis harness side connecter terminals

No.1 and No.4 ?

X-5E-27

YES

Are the chassis harness connector

terminals No.14 and No.3 ?

X-5I-32

Inspection of the Air Conditioner Room Temperature Setup System

• Conflicts Between the Set Temperature and Actual Room Temperature

NO Replace the failed sensor.

Failure on the automatic heater/air

conditioner control unit.

YES

Is the in car sensor intaking the room

air? (Refer to the later section on "Check

Up".)

Is the air mix link properly attached?

(Make sure that selecting FH or FC using

the lever respectively sets the mix door

to the full hot or full cool.)

Are the interior temperature sensor and

the outside air temperature sensor

functioning normally?

Failure on the in car sensor.

Failure on the air mix link or the actuator.

INDIVIDUAL INSPECTION

In Car Sensor

1. Disconnect the in car sensor connector (I-34).

2. Measure resistance between the in car sensor

side terminal No.3 and No.4 .

Sun Sensor

1. Disconnect the sun sensor connector (I-35).

2. Measure the current value on the sun sensor

when placed it approximately 15 cm away from

60W incandescent lamp.

Ambient Sensor

1. Disconnect the connector (C-86) on the ambient

sensor.

2. Measure resistance between the ambient

sensor side terminals.

I-34

Temperature on the Sensor

Temperature Detector(¡C)

Sensor Resistance

Value(k‰)

4321

-20

-10 0 10 20 30 40

17.09

9.93

3.75

2.24

6.0

1.6

30.69

865RX007

‰

0100-10-20 30 4020

Temperature on the Sensor

Temperature Detector(¡C)

Sensor Resistance

Value(k‰)

17.09

30.69

9.93

6.0

3.75

2.24

1.6

C01RX012

—

Testing rod

Current

value

40 A or more

1 2

D06RY00001

Power Transistor

1. Remove the power transistor connector (I-47)

from the evaporator assembly.

2. Check the conduction between the power

transistor side terminals.

MAX HI Relay

1. Remove the MAX HI relay connector (B-64) from

the blower assembly.

2. Check the conduction between the MAX HI relay

side terminals.

In Car Sensor

1. Turn on the ignition switch (the engine is

started). Start the air conditioner in "Full Auto".

2. Make sure that the in car sensor suctions

cigarette smokes and such.

3. Dismount the in car sensor from the automatic

heater/air conditioner control unit. Connect (+)

end and (-) end of the battery to the aspirator

motor side terminals No.1 and No.2

, respectively, then

check if the motor runs normally.

I-34 I-34

4321

C01RW020

43 34

No continuity between terminals (2) and (4).

Continuity between terminal (2) and (4) when battery

voltage is applied between (1) and (3).

C01RY00003

Terminal

No. Conduction

Conducted (50‰ maximum)

Conducted (100‰ maximum)

Conducted (220‰ maximum)

Not conducted

123

Testing

rod

C01RY00002

ON-VEHICLE SERVICE

Power Transistor

Legend

(1) Evaporator Assembly

(2) Passenger Knee Bolster Reinforcement(3) Lower Cluster(4) Front Console(5) Glove Box

(6) Instrument Panel Passenger Lower Cover(7) Power Transistor Connector(8) Power Transistor

Removal1. Remove front console.

2. Remove lower cluster.

3. Remove glove box.

4. Remove instrument panel passenger lowercover.5. Remove passenger knee bolster reinforcement.6. Disconnect the power transistor connector.

7. Remove power transistor.

InstallationTo install, follow the removal step in the reverse

order.

Automatic Heater/Air Conditioner ControlUnit

Legend

(1) Connector

(2) Automatic Heater / Air Conditioner Control

Unit

(3) Instrument Panel Cluster

(4) Set Screw

Removal

1. Disconnect the battery ground cable.

2. Remove instrument panel cluster.

• Refer to Instrument Panel Assembly in Body

Structure section.

3. Disconnect the automatic heater / air conditioner

control unit connector.

4. Remove automatic heater/ air conditioner

control unit.

Installation

To install, follow the removal step in the reverse

order.

874RY00001

865RY00007

In Car Sensor

Legend

(1) In Car Sensor(2) Automatic Heater / Air Conditioner Control

Unit

Removal1. Disconnect the battery ground cable.2. Remove the automatic heater / air conditionercontrol unit.

•Refer to the automatic heater / air conditionercontrol unit section.

3. Remove in car sensor.

Installation

To install, follow the removal step in the reverse

order.

Ambient Sensor

Legend

(1) Ambient Sensor

(2) Sensor Connector

(3) Radiator Grill

Removal

1. Disconnect the battery ground cable.

2. Remove radiator grille.

• Refer to Radiator Grille in Body Structure

section.

3. Disconnect the ambient sensor connector.

4. Remove the ambient sensor.

Installation

To install, follow the removal step in the reverse

order.

865RY00006

875RY00001

Sun Sensor

Legend

(1) Sun Sensor

Removal

1. Disconnect the battery ground cable.

2. Remove the sun sensor.

3. Disconnect the sun sensor connector.

Installation

To install, follow the removal step in the reverse

order.

Electronic Thermostat

Legend

(1) Duct Sensor

(2) Thermostat Assembly

(3) Evaporator Assembly

Removal

1. Disconnect the battery ground cable.

2. Remove evaporator assembly.

• Refer to Evaporator Assembly section.

3. Remove electronic thermostat.

Installation

To install, follow the removal step in the reverse

order.

826RY00001

874RY00002

Techline

Mode Actuator

Legend

(1) A/T Control Unit

(2) Mode Actuator

(3) Actuator Rod

Removal

1. Disconnect the battery ground cable.

2. Remove the A/T control unit.

•The connector shall remain connected.

3. Remove the actuator rod.

4. Remove the mode actuator.

Installation

To install, follow the removal step in the reverse

order.

MIX Actuator

Legend

(1) Instrument Panel Assembly

(2) Instrument Panel Center Bracket

(3) Actuator Rod

(4) Mix Actuator

Removal

1. Disconnect the battery ground cable.

2. Remove the instrument panel assembly.

• Refer to the Instrument Panel Assembly in

Body Structure section.

3. Remove the instrument panel center bracket.

4. Remove the actuator rod.

5. Remove the mix actuator.

Installation

To install, follow the removal step in the reverse

order.

860RW030

20 25 30

AUTO

A/C

OFF

AUTO

860RY00004

Intake Actuator

Legend

(1) Evaporator Assembly

(2) Intake Actuator

(3) Intake Actuator Connector

Removal

1. Disconnect the battery ground cable.

2. Discharge and recover refrigerant.

• Refer to Refrigerant Recovery in this section.

3. Remove the evaporator assembly.

• Refer to Evaporator Assembly section.

4. Disconnect the intake actuator connector.

5. Remove the intake actuator.

Installation

To install, follow the removal step in the reverse

order.

860RX018