Page 3457 of 4179

TROUBLE DIAGNOSIS
ATC-61
C
D
E
F
G
H
I
K
L
MA
B
AT C
8. CHECK ACTUATORS
Refer to the following chart and confirm discharge air flow, air tem-
perature, blower motor voltage and compressor operation.
Checks must be made visually, by listening to any noise, or by touching air outlets with your hand, etc. for
improper operation.
*1: Step No. 41 to 46 are for differentiation and will not be displayed.
*2: FOOT position during automatic control. Refer to AT C - 6 3 , "
AUXILIARY MECHANISM: FOOT POSITION
SETTING TRIMMER" .
OK or NG
OK >> 1. Turn ignition switch OFF or intake switch ON.
2. INSPECTION END
NG >>
Air outlet does not change.
Go to Mode Door Motor Circuit. Refer to AT C - 7 3 , "
Mode Door Motor Circuit" .
Intake door does not change.
Go to Intake Door Motor Circuit. Refer to AT C - 7 9 , "
Intake Door Motor Circuit" .
Blower motor operation is malfunctioning.
Go to Blower Motor Circuit. Refer to AT C - 8 2 , "
Blower Motor Circuit" .
Magnet clutch does not engage.
Go to Magnet Clutch Circuit. Refer to AT C - 8 8 , "
Magnet Clutch Circuit" .
Discharge air temperature does not change.
Go to Air Mix Door Motor Circuit. Refer to AT C - 7 6 , "
Air Mix Door Motor Circuit" .
RJIA0492E
Mode control dial position
STEP-No.
*1STEP-41 STEP-42 STEP-43 STEP-44 STEP-45 STEP-46
Mode control dial posi-
tionAUTO VENT B/LFOOT or
FOOT2D/F or D/F2 DEF
Mode door position VENT VENT B/L
FOOT
*2D/F DEF
Intake door position REC REC REC FRE FRE FRE
Air mix door position FULL COLD FULL COLD FULL COLD FULL HOT FULL HOT FULL HOT
Blower motor voltage Approx. 4.5V Approx. 10.5V Approx. 8.5V Approx. 8.5V Approx. 8.5V Approx. 12V
Compressor ON ON OFF OFF ON ON
Page 3458 of 4179

ATC-62
TROUBLE DIAGNOSIS
9. CHECK MALFUNCTIONING SENSOR
Refer to the following chart.
*1: Perform self-diagnosis STEP-2 under sunshine.
When performing indoors, aim a light (more than 60W) at sunload
sensor, otherwise LED of A/C switch will not indicate despite that
sunload sensor is functioning properly.
CAUTION:
When switched to STEP-2, LED of REC position blinks for
approximately 25 seconds.
*2: ATC-109, "
DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR" .
*3: AT C - 11 2 , "
DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR" .
*4: AT C - 11 4 , "
DIAGNOSTIC PROCEDURE FOR SUNLOAD SENSOR" .
*5: AT C - 11 7 , "
DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR" .
*6: AT C - 6 9 , "
DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT" .
>> INSPECTION END
10. CHECK MALFUNCTIONING DOOR MOTOR POSITION SWITCH
Mode and/or intake door motor position switch(es) is/are malfunc-
tioning.
CAUTION:
When switched to STEP-3, LED of REC position blinks for
approximately 50 seconds.
*1: AT C - 7 5 , "
DIAGNOSTIC PROCEDURE FOR MODE DOOR
MOTOR" .
*2: AT C - 8 1 , "
DIAGNOSTIC PROCEDURE FOR INTAKE DOOR MOTOR" .
>> INSPECTION END
SJIA0393E
Mode control dial position Unusual Malfunctioning sensor (Including circuits) Reference page
VENT
A/C LED: OFFAmbient sensor *2
B/L In-vehicle sensor *3
FOOT or FOOT2
Sunload sensor
*1*4
D/F or D/F2 Intake sensor *5
DEF Air mix door motor (LCU) PBR *6
Unusual Mode or intake door position Reference page
REC LED: ON Mode door motor *1
FRE LED: ON Intake door motor *2
SJIA0394E
Page 3459 of 4179

TROUBLE DIAGNOSIS
ATC-63
C
D
E
F
G
H
I
K
L
MA
B
AT C
AUXILIARY MECHANISM: TEMPERATURE SETTING TRIMMER
The trimmer compensates for differences in range of ±3°C between temperature setting (Temperature control
dial position) and temperature felt by driver.
Operating procedures for this trimmer are as follows:
1. Set temperature at 25°C.
2. Set fan control dial to OFF.
3. Turn ignition switch ON.
4. Set in self-diagnostic mode as follows. Within 10 seconds after starting engine (ignition switch is turned
ON.), press intake switch for at least 5 seconds.
5. Turn temperature control dial as desired. Temperature will change at a rate of 1°C each time a dial is
turned.
When battery cable is disconnected, trimmer operation is canceled. Temperature set becomes that of initial
condition, i.e. 0°C.
AUXILIARY MECHANISM: FOOT POSITION SETTING TRIMMER
Wind distribution ratio in FOOT mode can be set.
Operating procedures for this trimmer are as follows:
1. Set temperature at 25°C.
2. Set fan control dial to AUTO.
3. Turn ignition switch ON.
4. Set in self-diagnostic mode as follows. Within 10 seconds after starting engine (ignition switch is turned
ON.), press intake switch for at least 5 seconds.
5. Turn temperature control dial as desired.
Setting temperatureLED status of each switch
FRE REC A/C
−3°CON ON ON
−2°CON ON OFF
−1°CON OFF ON
0°C (Initial setting) OFF OFF OFF
1°COFFOFF ON
2°COFF ON OFF
3°C OFF ON ON
RJIA2825E
Page 3460 of 4179

ATC-64
TROUBLE DIAGNOSIS
AUXILIARY MECHANISM: INLET PORT MEMORY FUNCTION
When ignition switch is turned from OFF to ON, inlet port can be set to AUTO or manual.
Operating procedures for this trimmer are as follows:
1. Set fan control dial to 1st-25th speed.
2. Turn ignition switch ON.
3. Set in self-diagnostic mode as follows. Within 10 seconds after starting engine (ignition switch is turned
ON.), press intake switch for at least 5 seconds.
4. Press intake switch as desired.
Ty p eLED status of each switch
FRE REC A/C
Type-A (initial setting) OFF OFF ON
Ty p e - B O F F O N OF F
Ty p e - C O F F O N O N
Ty p e - D ON O F F OF F
LED status
of FRE
positionLED status
of REC posi-
tionSetting status
Setting changeover method
FRE REC
OFF OFF AUTO control AUTO control
Intake SW: ON OFF ON AUTO control (Initial setting)Manual REC status is memorized.
(Initial setting)
ON OFF Manual FRE status is memorized. AUTO control
ON ON Manual FRE status is memorized. Manual REC status is memorized.
Page 3461 of 4179

TROUBLE DIAGNOSIS
ATC-65
C
D
E
F
G
H
I
K
L
MA
B
AT C
Operational CheckEJS004GU
The purpose of the operational check is to confirm that the system operates properly.
CHECKING BLOWER
1. Turn fan control dial to 1st speed. Blower should operate on low
speed.
2. Turn fan control dial to 2nd speed, and continue checking
blower speed until all speeds are checked.
3. Leave blower on Max. speed.
If NG, go to trouble diagnosis procedure for AT C - 8 2 , "
Blower Motor
Circuit" .
If OK, continue the check.
CHECKING DISCHARGE AIR
1. Turn mode control dial to each position.
2. Confirm that discharge air comes out according to the air distri-
bution table. Refer to AT C - 3 2 , "
Discharge Air Flow" .
Intake door position is checked in the next step.
If NG, go to trouble diagnosis procedure for AT C - 7 3 , "
Mode Door
Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at FRESH when the D/F, D/F2
or DEF position is selected.
CHECKING INTAKE DOOR
1. Press intake switch. Recirculation indicator should illuminate.
2. Press intake switch again. Fresh indicator should illuminate.
3. Listen for intake door position change (you should hear blower
sound change slightly).
If NG, go to trouble diagnosis procedure for AT C - 7 9 , "
Intake Door
Motor Circuit" .
If OK, continue the check.Conditions : Engine running at usual operating temperature
SJIA0395E
SJIA0396E
RJIA0492E
SJIA0397E
Page 3462 of 4179

ATC-66
TROUBLE DIAGNOSIS
CHECKING TEMPERATURE DECREASE
1. Turn temperature control dial until 18°C.
2. Check for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for AT C - 9 6 , "
Insufficient
Cooling" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Turn temperature control dial until 32°C.
2. Check for hot air at discharge air outlets.
If NG, go to trouble diagnosis procedure for ATC-105, "
Insufficient
Heating" .
If OK, continue the check.
CHECKING A/C SWITCH
1. Turn fan control dial to AUTO position.
2. Press A/C switch.
Confirm that the compressor clutch engages (sound or visual
inspection). (Discharge air and blower speed will depend on
ambient, in-vehicle, and set temperatures.)
If NG, go to AT C - 6 7 , "
Power Supply and Ground Circuit for Auto
Amp." , then if necessary, trouble diagnosis procedure for AT C - 8 8 ,
"Magnet Clutch Circuit" .
If all operational checks are OK (symptom cannot be duplicated), go
to Incident Simulation Tests in GI-23, "
How to Perform Efficient Diag-
nosis for an Electrical Incident" and perform tests as outlined to sim-
ulate driving conditions environment. If symptom appears, refer to
AT C - 3 4 , "
SYMPTOM TABLE" and perform applicable trouble diagnosis procedures.
SJIA0398E
SJIA0399E
SJIA0400E
Page 3463 of 4179
TROUBLE DIAGNOSIS
ATC-67
C
D
E
F
G
H
I
K
L
MA
B
AT C
Power Supply and Ground Circuit for Auto Amp.EJS004GV
SYMPTOM: A/C system does not come on.
INSPECTION FLOW
COMPONENT DESCRIPTION
Auto Amp. (Automatic Amplifier)
The auto amp. has a built-in microcomputer which processes infor-
mation sent from various sensors needed for air conditioner opera-
tion. The air mix door motor, mode door motor, intake door motor,
blower motor and compressor are then controlled.
The auto amp. is unitized with control mechanisms. Signals from
various switches and Potentio Temperature Control (PTC) are
directly entered into auto amp.
Self-diagnostic functions are also built into auto amp. to provide
quick check of malfunctions in the auto air conditioner system.
*1AT C - 6 5 , "Operational Check".*2ATC-68, "DIAGNOSTIC PROCE-
DURE FOR A/C SYSTEM".
RJIA2826E
RJIA2824E
Page 3464 of 4179

ATC-68
TROUBLE DIAGNOSIS
Potentio Temperature Control (PTC)
The PTC is built into the auto amp. It can be set at an interval of 1°C
in the 18°C to 32°C temperature range by turning the temperature
control dial.
DIAGNOSTIC PROCEDURE FOR A/C SYSTEM
SYMPTOM: A/C system does not come on.
1. CHECK POWER SUPPLY CIRCUIT FOR AUTO AMP.
1. Disconnect auto amp. connector.
2. Check voltage between auto amp. harness connector M52 ter-
minal 1 (BR/Y), 2 (L), 20 (L/W) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check 10A fuses (Nos. 15 and 28) and 15A fuses (Nos. 19 and 24), located in the fuse block (J/
B). Refer to PG-75, "
FUSE BLOCK - JUNCTION BOX (J/B)" .
If fuses are OK, check harness for open circuit. Repair or replace if necessary.
If fuses are NG, replace fuse and check harness for short circuit. Repair or replace if necessary.
SJIA0402E
RJIA0504E
Terminals Ignition switch position
(+)
(-) OFF ACC ON
Auto amp.
connectorTe r m i n a l N o .
(wire color)
M52 1 (BR/Y)
GroundApprox.
0VApprox.
0VBattery
voltage
M52 2 (L)Battery
voltageBattery
voltageBattery
voltage
M52 20 (L/W)Approx.
0VApprox.
0VBattery
voltage
RJIA2856E