Page 847 of 1226

DIAGNOSTIC PROCEDURE
SYMPTOM: Intake door does not change.
CHECK POWER SUPPLY FOR INTAKE
DOOR MOTOR.
Disconnect intake door motor harness con-
nector.
Do approx. 12 volts exist between intake
door motor harness terminal No.j
1and
body ground?
Ye s
cNo
Check 10A (No.) fuse
at fuse block.
(Refer to ``POWER SUP-
PLY ROUTING'' in EL sec-
tion and Wiring Diagram.)
CHECK GROUND CIRCUIT FOR INTAKE
DOOR MOTOR.
Check continuity between intake door
motor harness terminal and body ground.
Continuity should exist.
OK
cNG
Disconnect recirculation
switch harness connector.
Note
Check continuity between
recirculation switch harness
terminal No.j
1(j2) and
intake door motor harness
terminal No.j
13(j14).
Continuity should exist.
If OK, check harness for
short.
OK
CHECK INTAKE DOOR LINKAGE.
Refer to Control Linkage Adjustment. (HA-
27)
OK
Replace intake door motor.
jA
TerminalRecirculation
switch condition
Body groundj
14FRE
j
13REC
Note:
If the result is NG or No after checking circuit continuity, repair harness or
connector.
RHA350FB
RHA590G
RHA591G
.
.
.
..
TROUBLE DIAGNOSESMANUAL
Intake Door Motor (Cont'd)
HA-26
Page 848 of 1226

jA
Note
CHECK GROUND CIRCUIT FOR RECIR-
CULATION SWITCH.
Check circuit continuity between recircula-
tion switch harness terminal No.j
4and
body ground.
Continuity should exist.
If OK, check harness for short.
OK
CHECK RECIRCULATION SWITCH.
(Refer to Electrical Components Inspec-
tion.) (HA-27)
cNG
Replace recirculation
switch.
Note:
If the result is NG or No after checking circuit continuity, repair harness or
connector.
ELECTRICAL COMPONENTS INSPECTION
Recirculation switch
Check continuity between terminals at each switch position.
Terminal No.
Recirculation
switch conditionContinuity
(+) (þ)
j
1j4REC Yes
FRE No
j
2j4REC No
FRE Yes
CONTROL LINKAGE ADJUSTMENT
Intake door motor
1. Install intake door motor on intake unit.
Ensure that the intake door motor lever is ®tted into the slit
portion of intake door link.
2. Connect the intake door motor harness connector.
3. Turn ignition switch to ON.
4. Check that intake door operates properly when RECIRCULA-
TION switch is turned ON and OFF.
RHA582FB
RHA768F
RHA593F
.
.
TROUBLE DIAGNOSESMANUAL
Intake Door Motor (Cont'd)
HA-27
Page 856 of 1226

PERFORMANCE CHART
Test condition
Testing must be performed as follows:
Vehicle location: Indoors or in the shade (in a well-ventilated place)
Doors: Closed
Door window: Open
Hood: Open
TEMP.: Max. COLD
Discharge Air: Face Vent
REC switch: (Recirculation) set
FAN speed: High speed
Engine speed: Idle speed
Operate the air conditioning system to 10 minutes before taking
measurements.
Rear cooler: ON (For rear cooler equipped model only)
Test reading (Single A/C equipped model)
Recirculating-to-discharge air temperature table
Inside air (Recirculating air) at blower assembly inlet
Discharge air temperature at center ventilator ÉC (ÉF)
Relative humidity % Air temperature ÉC (ÉF)
50-6025 (77) 8.0 - 10.0 (46 - 50)
30 (86) 12.0 - 15.0 (54 - 59)
35 (95) 16.0 - 20.0 (61 - 68)
40 (104) 20.5 - 24.5 (69 - 76)
60-7025 (77) 10.4 - 13.0 (51 - 55)
30 (86) 15.0 - 18.0 (59 - 64)
35 (95) 19.5 - 23.4 (67 - 74)
40 (104) 24.5 - 28.5 (76 - 83)
Ambient air temperature-to-operating pressure table
Ambient air
High-pressure (Discharge side)
kPa (bar, kg/cm
2, psi)Low-pressure (Suction side)
kPa (bar, kg/cm2, psi)
Relative humidity %Air temperature
ÉC (ÉF)
50-7025 (77)1,373 - 1,471 (13.73 - 14.71,
14.0 - 15.0, 199 - 213)196 - 245 (1.96 - 2.45,
2.0 - 2.5, 28 - 36)
30 (86)1,275 - 1,520 (12.75 - 15.20,
13.0 - 15.5, 185 - 220)226 - 284 (2.26 - 2.84,
2.3 - 2.9, 33 - 41)
35 (95)1,412 - 1,716 (14.12 - 17.16,
14.4 - 17.5, 205 - 249)255 - 314 (2.55 - 3.14,
2.6 - 3.2, 37 - 46)
40 (104)1,608 - 1,932 (16.08 - 19.32,
16.4 - 19.7, 233 - 280)294 - 353 (2.94 - 3.53,
3.0 - 3.6, 43 - 51)
TROUBLE DIAGNOSESMANUAL
Insufficient Cooling (Cont'd)
HA-35
Page 859 of 1226

Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.
AC354A
+Air conditioner system does
not function and does not
cyclically cool the compart-
ment air.
+The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not discharge
cyclically.
¯
Moisture is frozen at expansion
valve outlet and inlet.
¯
Water is mixed with refrigerant.+Drain water from refrigerant
or replace refrigerant.
+Replace liquid tank.
Low-pressure side becomes
negative.
AC362A
Liquid tank or front/rear side of
expansion valve's pipe is
frosted or dewed.High-pressure side is closed
and refrigerant does not ¯ow.
¯
Expansion valve or liquid tank
is frosted.Leave the system at rest. Start
it again to check whether or not
the problem is caused by water
or foreign particles.
+If water is the cause, initially
cooling is okay. Then the
water freezes, causing a
blockage. Drain water from
refrigerant or replace refriger-
ant.
+If due to foreign particles,
remove expansion valve and
remove the particles with dry
and compressed air.
+If either of the above meth-
ods cannot correct the
problem, replace expansion
valve.
+Replace liquid tank.
+Check lubricant for contami-
nation.
TROUBLE DIAGNOSESMANUAL
Trouble Diagnoses for Abnormal Pressure
(Cont'd)
HA-38
Page 868 of 1226
ELECTRICAL COMPONENTS INSPECTION
A/C switch
Check continuity between terminals at each switch position.
Switch condition Terminal No.
Continuity
A/C (+) (þ)
ON
j
2j1Ye s
OFF No
A/C relay
Check continuity between terminalsj3andj5,j6andj7.
Condition Continuity
12V direct current supply between
terminalsj
1andj2Ye s
No current supply No
Dual-pressure switch
ON
kPa (bar, kg/cm2, psi)OFF
kPa (bar, kg/cm2, psi)
Low-pressure sideIncreasing to 157 - 216
(1.57 - 2.16, 1.6 - 2.2,
23 - 31)Decreasing to 157 - 196
(1.57 - 1.96, 1.6 - 2.0,
23 - 28)
High-pressure sideDecreasing to 1,863 -
2,256 (18.6 - 22.6,
19 - 23, 270 - 327)Increasing to 2,452 -
2,844 (24.5 - 28.4,
25 - 29, 356 - 412)
Thermo control amp.
Evaporator outlet air
temperature
ÉC (ÉF)Thermo amp. operation Tester
Decreasing to 0.1 - 0.9
(32 - 34)Turn OFF Approx. 12V
Increasing to 2.5 - 3.5
(37 - 38)Turn ON Approx. 0V
RHA626G
SEC202B
RHA628G
RHA736G
TROUBLE DIAGNOSESMANUAL
Magnet Clutch (Cont'd)
HA-47
Page 870 of 1226

Introduction
AIR CONDITIONER LAN SYSTEM OVERVIEW CONTROL SYSTEM
The LAN system consists of auto amp., air mix door motor and mode door motor.
A con®guration of these components is shown in the diagram below.
Features
SYSTEM CONSTRUCTION (LAN)
A small network is constructed between the auto ampli®er, air mix door motor and mode door motor. The auto
ampli®er and motors are connected by data transmission lines and motor power supply lines. The LAN net-
work is built through the ground circuits of the two motors.
Addresses, motor opening angle signals, motor stop signals and error checking messages are all transmitted
through the data transmission lines connecting the auto ampli®er and two motors.
The following functions are contained in LCUs built into the air mix door motor and the mode door motor.
+Address
+Motor opening angle signals
+Data transmission
+Motor stop and drive decision
+Opening angle sensor (PBR function)
+Comparison
+Decision (Auto ampli®er indicated value and motor opening angle comparison)
RHA439G
RHA440GA
DESCRIPTIONAUTO
HA-49
Page 883 of 1226

AUTO AMP. INSPECTION TABLE
TERMINAL
No.ITEM CONDITIONVoltage
V
1 Power supply for IGN
Ð Approximately 12
2 Power supply for BAT
Ð Approximately 12
3 Ground Ð Ð
4 Compressor ON signal
CompressorON Approximately 0
OFF Approximately 12
5Power supply for mode and air mix
door motor
Ð Approximately 12
8 In-vehicle sensor Ð Ð
9 Ambient sensor Ð Ð
10 Sunload sensor Ð Ð
11 Ground Ð Ð
12 Power supply for illumination
Illumination switch ON Approximately 12
13 Intake door position switchRECIRCULATION Approximately 0
FRESH or 20% FRESH Approximately 12
14 Intake door position switchFRESH Approximately 0
RECIRCULATION or 20% FRESH Approximately 12
15 LAN signal Ð Approximately 5.5
17 Fan control amp. control signal Fan speedLow, middle low or middle high Approximately 2.5 - 3.0
High Approximately9-10
18 Blower motor feed back Ð Approximately 12
20 Power supply for blower motor
Ð Approximately 12
21 Thermal transmitter Ð Ð
23 Intake door position switch
20% FRESH Approximately 0
RECIRCULATION or FRESH Approximately 12
24 Sensor ground Ð Ð
25 Intake sensor Ð Ð
28 Rear cooler relay
Rear cooler ON Approximately 0
Rear cooler OFF Approximately 12
35 Rear cooler switchRear cooler switch ON Approximately 0
Rear cooler switch OFF Approximately 12
TROUBLE DIAGNOSESAUTO
Auto Amp. Terminals and Reference Value
(Cont'd)
HA-62
Page 891 of 1226
Operational Check
The purpose of the operational check is to con®rm that the system
operates properly.
CONDITIONS
+Engine running and at normal operating temperature.
PROCEDURE
1. Check memory function
a. Set the temperature 25ÉC.
b. Press OFF switch.
c. Turn the ignition off.
d. Turn the ignition on.
e. Press the AUTO switch.
f. Con®rm that the set temperature remains at previous tempera-
ture.
g. Press OFF switch.
2. Check blower
a. Press fan switch one time.
Blower should operate on low speed.
The fan symbol should have one blade lit
.
b. Press fan switch one more time, and continue checking blower
speed and fan symbol until all speeds are checked.
c. Leave blower on MAX speed
.
3. Check discharge air
a. Press mode switch four times and DEF button.
RHA517G
RHA518G
RHA519G
RHA520G
TROUBLE DIAGNOSESAUTO
HA-70